Manual-DucTester Operation &

Commercial DucTester
Operation Manual
Model 400 Blower
Model 441, 451, 442 &
452 Systems
rev-2017-04-20
Made by Retrotec
1060 East Pole Road
Everson, WA USA 98247
For support:
Call 1(888) 330-1345 in USA
+1 (360) 738-9835 outside USA support@retrotec.com or
Fax +1(360) 647-7724
Manual for:
Models 441 & 451 (with DM32) and Model 442 & 452 (with DM32 WiFi)
Page 2 of 79
© Retrotec 2017
Copyright © 2014-2017 Retrotec
All rights reserved.
This document contains materials protected under International and Federal Copyright Laws. No part of
this book may be reproduced or transmitted in any form or by any means, electronic or mechanical,
including photocopying, recording, or by any information storage and retrieval system without express
written permission from Retrotec.
Retrotec makes no warranties with respect to this documentation and disclaims any implied warranties
of merchantability, quality, or fitness for any particular purpose. The information in this document is
subject to change without notice. Retrotec reserves the right to make revisions to this publication
without obligation to notify any person or entity of any such changes.
DucTester, Infiltrometer, FanTestic are Trademarks of Retrotec. Other trademarks or brand names
mentioned herein are trademarks or registered trademarks of their respective owners.
Retrotec test fans, blower door systems, duct testing systems and gauges have been calibrated in our laboratory
which is accredited by the ANSI-ASQ National Accreditation Board to meet requirements of international standard
ISO/IEC 17025:2005. All pressure and flow devices used in the calibration are traceable to the National Institute of
Standards and Technology and themselves have ISO 17025 accreditation.
Retrotec equipment and software complies with the following standards:
ASTM E779-10, ASTM E-1554, ATTMA TSL1, ATTMA TSL2, CGSB 149.10, DW/143, Energy Star, EN12237, EN13829,
EN15004, FD E51-767, ISO 9972-2015, ISO 14520-2006, NEN2686, NFPA 2001-2015, RESNET, SMACNA-2002, All
USA State Energy Codes, Title 24 and USACE Protocol.
Custom calibration available upon request
2016-08-17 Appendix H on calibration added.
Page 3 of 79
© Retrotec 2017
Table of Contents
Important equipment-related safeguards .......................................................................... 6
Important occupant safeguards during testing ................................................................... 7
1. Model 300 / 400 System Types: ....................................................................9
2. DucTester systems using Model 400 Calibrated fan .................................... 10
2.1
Retrotec calibrated fan: Model 400 Operation ...................................................... 11
2.2
451 systems include 10-2.5 (250-63 mm) Adapter for 4 inch (100mm) Flex Duct .... 13
2.2.1.
451 Range Configurations ..................................................................................... 13
2.2.2.
451 Flows .............................................................................................................. 13
2.3
441 systems connect directly to 10” (250 mm) Flex Duct ....................................... 15
2.3.1.
Flow Range Configurations ................................................................................... 15
2.3.2.
Test Blower Min/Max Flows ................................................................................. 16
2.4
Digital Gauge ........................................................................................................ 17
2.5
Flex Duct .............................................................................................................. 17
2.6
Additional duct testing components ..................................................................... 18
2.6.1.
Grill Mask for sealing registers ............................................................................. 18
2.6.2.
Umbilical for connecting fan and DM32 gauge .................................................... 18
2.6.3.
Optional 10 to 2.5 (250 to 63 mm) inch adapter makes it a Model 451 .............. 18
2.6.4.
Duct Connection Flange ........................................................................................ 18
2.6.5.
Toolbag keeps all testing components in one place ............................................. 18
2.6.6.
Tubing Accessory Kit ............................................................................................. 19
3. Types of Duct Leakage Tests ....................................................................... 20
4. Prepare for the Duct Leakage Test .............................................................. 21
4.1
Unpack, connect the gauge to the DucTester ........................................................ 21
4.2
Charge the gauge .................................................................................................. 22
4.3
Follow the Quick Guide that came with your system ............................................. 23
5. Test Procedure – (Steps 1 to 7) ................................................................... 24
5.1
Step 1 - Prepare the gauge .................................................................................... 24
5.2
Step 2 – Determine test criteria and prepare the ducts.......................................... 25
5.3
Step 3 – Connect DucTester to ducts ..................................................................... 26
5.3.1.
Select a test direction ........................................................................................... 26
5.3.2.
Setting up for pressurization ................................................................................ 27
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© Retrotec 2017
5.3.3.
Setting up for depressurization ............................................................................ 27
5.3.4.
Install Range Configuration on fan ....................................................................... 27
5.4
Step 4 –Tubing, control and power connections .................................................... 28
5.5
Step 5 – Set up Test Pressure and Area in Gauge ................................................... 30
5.6
Step 6 – Run Test Blower to Measure the Leakage ................................................ 31
5.7
Step 7 – Test Passes .............................................................................................. 31
6. Troubleshooting ......................................................................................... 32
6.1
If test fails ............................................................................................................ 32
6.2
If no Results are displayed (“--” appears on display) .............................................. 32
6.3
Cannot achieve test pressure ................................................................................ 33
6.4
Gauge “Flow” reading does not change? Turn off [@] ........................................... 33
6.5
Fan does not run................................................................................................... 33
6.6
Avoid common mistakes ....................................................................................... 33
7. Find duct leaks ........................................................................................... 34
7.1
Using a smoke puffer ............................................................................................ 34
7.2
Using theatrical smoke ......................................................................................... 34
7.3
Using an infrared camera ...................................................................................... 34
7.4
Using a wet hand .................................................................................................. 34
8. Field Check the DucTester to find out what is not working ......................... 35
8.1
Field Check the gauge ........................................................................................... 35
8.2
Field Check the DucTester as a system .................................................................. 35
Appendix A
Flow Conversion Tables .............................................................. 37
Appendix B
U.S. Duct Leakage - Calculation (SMACNA) ................................. 42
B.1
Leakage Class........................................................................................................ 42
B.2
Leakage Class Lookup ........................................................................................... 44
B.3
Leakage Factor ..................................................................................................... 45
B.4
Pressure Class ....................................................................................................... 48
Appendix C
U.S. Duct Leakage - Measurement Procedure 1 (CFM/100 sq ft) . 49
C.1
How much duct surface area can be tested at one time? ....................................... 50
C.2
Checklist ............................................................................................................... 51
C.2.3.
Step 2 – Determine test criteria and prepare the ducts....................................... 52
C.2.4.
Step 3 – Connect DucTester to ducts.................................................................... 53
C.2.5.
Step 4 –Tubing, control and power connections .................................................. 53
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© Retrotec 2017
C.2.6.
Step 5 – Set up Test Pressure and Area in Gauge ................................................. 53
C.2.7.
Step 6 – Measure Leakage Factor in CFM/100 sq ft ............................................. 54
C.2.8.
Step 7 – Test Passes .............................................................................................. 54
C.3
If ducts fail, measure the Leakage Class ................................................................. 54
Appendix D U.S. Duct Leakage - Measurement Procedure 2 (CFM at Test
Pressure or % Leakage) ..................................................................................... 55
D.1
How much duct surface area can be tested at one time? ....................................... 56
D.2
What Air Handler Flow Rate can be tested at one time? ........................................ 57
D.3
Checklist ............................................................................................................... 58
Appendix E
UK Duct Leakage Calculation (DW/143) ...................................... 62
E.1
Ductwork Classification and Air Leakage Limits ..................................................... 62
E.2
Test Sheet ............................................................................................................ 62
E.3
UK Measurement Procedure (Summary) ............................................................... 63
E.4
UK Measurement Procedure (Detailed)................................................................. 64
Appendix F
European Duct Leakage Calculation (EN12237)........................... 68
F.1
Ductwork Classification ........................................................................................ 68
F.2
Air Leakage Limits ................................................................................................. 68
F.3
EU Measurement Procedure ................................................................................. 69
F.4
EU How much duct surface area can be tested at one time? .................................. 70
F.5
European Measurement Procedure for Airtightness Class ..................................... 71
Appendix G
Calculate Flow using gauge readings .......................................... 75
Appendix H
Calibration Procedure for Model 450 ......................................... 76
H.1
Pressure Gauge..................................................................................................... 76
H.2
Flow Measurement............................................................................................... 76
H.3
Flow Calibration Field Check ................................................................................. 77
H.4
Fan Calibration Data ............................................................................................. 77
Glossary ............................................................................................................ 78
Important equipment-related safeguards
When using electrical appliances, basic safety precautions should always be followed. If Retrotec
equipment is used in a manner that does not follow the information provided in this manual, safety to
the operator and equipment performance may be impaired.
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© Retrotec 2017
Please read the following carefully before using your DucTester:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
This blower will create high pressures that may damage duct work if speed is not increased
slowly.
Avoid contact with moving parts.
Special attention should be made to keep children and pets away from the fan when it is
operating.
Do not insert anything into the fan casing while the fan is moving.
Ensure that no debris is inside the blower housing before operating it.
Keep hands, hair and clothing away from fan at all times.
The fan can cause damage or injury if it were to fall on someone/something.
Do not use equipment for other than its intended use.
Do not stand on the fan, or use the fan to support the weight of another object.
To protect against risk of electric shock, do not place this equipment or power cord in water or
other liquid.
Press the power plug firmly into the power receptacle on the fan. Failure to do so can cause
over-heating of the power cord and damage the fan.
Do not use ungrounded outlets or adapter plugs. Never remove or modify the grounding prong.
Do not operate any device with a damaged electrical cord, or after an equipment malfunction.
Use only the included power plug to operate the fan.
Turn the unit off and unplug from any electrical outlet before moving and when not in use, or
when making any adjustments to the fan motor or electrical components.
For use under indoor conditions only.
For use where there is no exposure to water or dusty substances or explosive materials or
flammable materials.
Ensure proper cooling of the blower motor by leaving the openings in the rear of the blower
housing open at all times.
Equipment is intended for diagnostic testing and to be operated for brief periods under
supervision by a qualified operator. Not to be used in a role as a household appliance for the
purpose of moving air.
Failure to follow these instructions carefully may result in bodily injury, damage to property
and/or equipment failure. Failing to operate equipment as intended may void warranty and
compliance with CE mark and other listings.
Important occupant safeguards during testing
Please read the following carefully before carrying out tests:
•
•
•
•
If dust, pollen, mold spores, chemicals or other undesirable substances can get blown into
working spaces, keep those susceptible to these substances away from the test area, and wear
dust masks.
Do not pressurize a duct system with air that is polluted or exposed to any toxic substances. For
example, blowing air from a car-port into a house or duct system while a motor vehicle is
running can quickly fill a house with toxic carbon monoxide.
If combustion safety problems are found, tenants and building owners should be notified
immediately and steps taken to correct the problem including notifying a professional heating
contractor if basic remedial actions are not available.
Air sealing duct work may change the pressure balance in a building and cause back drafting
where it did not occur before. For example, a return leaking to outdoors may have pressurized a
building but when corrected, leaky supplies may reverse that and cause depressurization which
could result in back drafting hot water heaters, furnaces or fireplaces.
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© Retrotec 2017
•
•
Be aware of all possible sources of combustion. Ensure any appliances do not turn on during the
test. Turn off power to the appliance, or set the appliance to the "Pilot" setting. It is possible
for flames to be sucked out of a combustion air inlet (flame rollout) during a test, which is a fire
hazard and can result in high carbon monoxide levels.
If combustion safety problems are found, tenants and building owners should be notified
immediately and steps taken to correct the problem (including notifying a professional heating
contractor if basic remedial actions are not available). Remember, the presence of elevated
levels of carbon monoxide in ambient building air or in combustion products is a potentially life
threatening situation. Air sealing work should not be undertaken until existing combustion
safety problems are resolved, or unless air sealing is itself being used as a remedial action.
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© Retrotec 2017
1. Model 300 / 400 System Types:
341
351
301
441/451
The US DucTester system
is powerful enough to test
leaky ducts that are found
in both new and existing
homes. New ranges will
go down to tight ducts
also.
‘European DucTester’
tailored for European
ducts. Comes with all the
Ranges needed for the
tightest ducts but just
add the aluminum frame
to test houses.
The Model 300 is ideal
for testing tight houses
as large as a 1600
square feet of floor area
that leak as much as 3
Airchanges per Hour.
Commercial duct
testing up to 20 in WC
(5000 Pa) in a
compact package.
The Model numbers with only 00 400 refer to the fan body.
The 1 in system 451 is used to show the system comes with a DM32 gauge, whereas the 2 in Model 452
means it comes with a DM32 WiFi gauge.
The middle 4 in the Model 441 shows the system has a 10 to 2.5 inch (250 to 63 mm) Adapter that goes
over the fan inlet to allow for pressurization.
The Model 400 Blower shares its housing, inlet nozzles and Flow Plates with the 300 models as shown
below. Each system is specialized for a certain application, and uses the most appropriate Blower for
the application.
The Model 451 is meant exclusively for testing commercial ducts at 10 to 100 times the test pressure
used for US residential duct that are tested at 25 Pa normally and sometimes 50 Pa. The Model 451 has
10 times the power and is much heavier than the 351 but still a fraction of the weith of old fashioned
Commercial duct testers in common use. The Model 441 system is for pressurization testing only, and
the Model 451 can be used to test both directions.
The Model 341 is used primarily in the US for relatively leaky US made ducts.
The Model 351 is for tighter European ducts that often have to be 100 times tighter than US ducts. The
Model 301 is simply the same fan but attached to a door panel for testing tight houses, apartment,
rooms or enclosures.
This manual focuses on the Model 400 Blower and attachments that make up 441 and 451 Systems. Be
sure to refer to the Quick Guide that came with your system or which can be obtained online at:
http://retrotec.com/support/manuals-guides
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© Retrotec 2017
2. DucTester systems using Model 400 Calibrated fan
Retrotec’s DucTester was specifically designed for testing ducts and tight enclosures. It has more than
three times the power necessary to test the leakiest duct system to current standards. The backward
curved centrifugal impeller is perfect for creating high test pressures. The elliptical nozzle is extremely
stable in both the pressurization and depressurization test directions, where it offers equivalent
accuracy in both directions.
A Flow Conditioner is not needed with Retrotec fans for depressurization testing. Some duct testing
fans require a flow conditioner when depressurizing a duct system, in order to get correct readings. The
Retrotec DucTester does not require a flow conditioner because it uses a flow nozzle, which is
intrinsically stable in either direction because the flow gets compressed as it goes through the nozzle.
All Retrotec models comply with ASTM E1554-07, ANSI/ASHRAE 152, ASTM E779-10, EN 13829, ATTMA
TS-1, CGSB 149.10, ASME and RESNET standards.
The calibrated fan measures flow by measuring the pressure developed inside the fan, which is often
called Fan Pressure. As the fan speeds up, a suction pressure develops at the inlet of the fan that causes
air to flow. By measuring this Fan Pressure, airflow is calculated using flow equations that are inside the
Retrotec gauge and FanTestic software.
When the test blower is operated, the Fan (Blower) Pressure can become too small to accurately
measure flow. To increase the Fan Pressure, a restriction plate is placed in front of the fan. The fan,
consequently, has to turn faster to maintain the same room or duct pressure, which creates a larger,
more accurate Fan Pressure. By providing a set of flow restricting plates with calibrated holes, Retrotec
DucTester fans can measure flows from 0.01 to 1400 m3/h. These restricting plates are called Ranges or
Range Configurations.
The Model 400 blower will create a variable flow over a wide range of pressures. Models 441 and 442
systems include all the accessories needed to connect to ducts under a positive test pressure. Models
451 and 452 include additional accessories to test under negative pressure also.
Many U.S. Standards require the test apparatus to have an accuracy of +/- 7.5% for flow rate and test
pressure and must have a certificate signifying conformance with the ASME. The Model 40 has a
standard accuracy of 3% for flow and less than 1% for pressure and complies with ASME, ASTM and ISO
standards. Accuracies of 1.5% for flow and 0.5% for pressure that are NIST traceable are available with
special calibrations but the standard accuracy is much greater than necessary for normal testing.
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© Retrotec 2017
2.1
Retrotec calibrated fan: Model 400 Operation
The Model 400 fan has 1700 Watt blower. Choose 120 or 240 Volts AC; 50 to 60 Hz is acceptable for
either choice. The powercord on the 120V AC unit is permanently mounted through the front of the fan
housing while the 240 V AC unit’s power cord is detatchable and mounts on the left side. The Model
400 Fan has an on/off switch on the left hand Control Panel.
The Model 400 Fan has a speed control built into the Fan . Speed is controlled using the knob on the
400 fan which is located on the right hand control panel or the Retrotec digital gauge. Either choice can
control the fan to any desired Set Speed.
The right hand control panel has two CAT-5 connectors. One of these is used to connect to any Retrotec
gauge for speed control purposes; the fan itself is never connected to the Internet. The second CAT-5
connection allows this fan to be daisy chained to a second fan, making them receive the same % speed
signal and making two fans run in unison. The control signal from one gauge will thus run both fans.
power input connection
.
Figure 1: Retrotec Model 400 has a speed control knob and two Ethernet style Speed Control Ports for daisy chaining
speed controls for running many fans together. The yellow and green color coded tubing connections to the gauge are
shown.
The Model 400 has 8 Flow (Fan Pressure) sensors located inside the fan inlet, and 4 self-referencing
pickups located just above and below the fan inlet which are connected to the single green and yellow
ports. The End Plate is permanently taped on so you normally don’t get this view. The Polyurethane
tape may be removed for cleaning: use the long lasting tape that comes with your system to reinstall
the End Plate.
Figure 2: Fan Pressure sensors are located in the fan inlet.
The 4 Flow sensors are located just inside the fan inlet, behind the protective grill. Together, they
measure the Fan Pressure, from which the fan airflow is calculated in the gauge. If the sensors become
Page 11 of 79
© Retrotec 2017
blocked, it is possible to clear them by attaching a pressure tube to the yellow Ref B port, and blowing
air through the tube gently.
The exterior of the inlet has the 4 self-referencing pressure pickups. They are connected to the green
Input B port, and are used as the reference for the Flow (Fan Pressure) Sensors. Self-referencing
ensures that the measured pressure difference is always accurate, no matter what the direction of flow
is with respect to the location of the gauge and operator and whether or not a flex duct is attached to
the inlet of the fan.
Figure 3 Back view shows massive blower with cover and cooling openings that should not be restricted.
Figure 4: Self-referencing pressure pickup connect to the green port and must never be taped over.
Page 12 of 79
© Retrotec 2017
2.2
451 systems include 10-2.5 (250-63 mm) Adapter for 4 inch
(100mm) Flex Duct
A complete 451 DucTester includes a calibrated fan, a digital dual-channel Model DM32 digital touch
screen pressure gauge, and a Flex Duct with flange to attach the fan to a register. Systems also include a
hard-sided fan case, an AC adaptor for the gauge, and a roll of Grill Mask. All pressure tubing and
Control Cables are bundled together securely in one easy to use Umbilical cable (included), and the
optional tubing accessory kit contains T connectors and tube lengths for other non-typical tasks.
2.2.1.
451 Range Configurations
All Retrotec calibrated fans have multiple Range Configurations in order to measure a wide range of air
leakage flow rates. Select the correct Range Configuration by running the fan speed up to over 50%
speed and checking that the gauge is giving a flow result. If not, change to a lower range and repeat.
Open cannot be used for
ducts
74
47
29
18
11
7
Figure 5: Range 74 is for the leakiest ducts while the smaller ranges are for progressively tighter ducts.
A calibrated fan measures flow by measuring the pressure developed inside the fan, which is often
called Fan Pressure. As the fan speeds up, a suction pressure develops at the inlet of the fan that causes
air to flow. By measuring this Fan Pressure, airflow is calculated using flow equations that are inside the
Retrotec gauge and FanTestic software.
When the fan slows down, the Fan Pressure can become too small to accurately measure flow. To
increase the Fan Pressure, a restriction plate is placed in front of the fan. The fan, consequently, has to
turn faster to maintain the same room or duct pressure, which creates a larger, more accurate Fan
Pressure. By providing a set of flow restricting plates with calibrated holes, Retrotec DucTester fans can
measure flows from 0.01 to 1400 m3/h.
The 450 system has 4 standard Range Configurations: 74, 47, 29, 18. The numbered Ranges are 100 mm
Plugs that snap into the End Plate, (labeled “300”), and will restrict the flow to allow you to develop
enough fan pressure to measure lower flow rates. The numbers refer to the approximate hole diameter
in millimeters. Most ducts can be tested using Range 47.
2.2.2.
451 Flows
When depressurizing, the Flex Duct or Flex Duct Adapter must be removed in order to change the
Ranges.
Page 13 of 79
© Retrotec 2017
3
CFM
CFM
minimum maximum
115
305
110
274
48
206
17
77
6.8
30
2.7
12
1.1
4.7
0.29
1.3
0.14
0.49
0.05
0.20
m3/h
m3/h
minimum maximum
195
500
187
495
81
350
29
130
12
51
4.6
20.5
1.8
8.0
0.50
2.2
0.25
0.83
0.09
0.33
Range
Name
74
74*
47
29
18
11
7
3
2
1
Included
Range
Name
74
74*
47
29
18
11
7
3
2
1
Included
yes
yes
yes
yes
yes
optional
optional
optional
optional
optional
yes
yes
yes
yes
yes
optional
optional
optional
optional
optional
*When Range 74 is used with 10-4” adapter on fan inlet (fan is depressurizing duct and Channel A is negative)
Table 1 Minimum and Maximum flows for 451 Range Plugs
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© Retrotec 2017
Figure 6: A complete Model 451 duct testing system showing 3 optional Flow Plugs and one blanking plug.
2.3
441 systems connect directly to 10” (250 mm) Flex Duct
A complete 441 DucTester includes a calibrated fan, a digital dual-channel Model DM32 digital touch
screen pressure gauge, and a 4” Flex Duct to attach the Test Blower to the duct.
2.3.1.
Flow Range Configurations
All Retrotec calibrated fans have multiple Range Configurations in order to measure a wide range of air
leakage flow rates. Select the correct Range Configuration by running the fan speed up to over 50%
speed and checking that the gauge is giving a flow result. If not, change to a lower range and repeat.
Open cannot be used for
ducts
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© Retrotec 2017
74
47
29
18
11
7
3
Figure 7: Range 74 is for the leakiest ducts while the smaller ranges are for progressively tighter ducts.
The 440 system has 4 standard Range Configurations: 74, 47, 29, 18. The numbered Ranges are 100 mm
Plugs that snap into the End Plate, (labeled “300”), and will restrict the flow to allow you to develop
enough fan pressure to measure lower flow rates. The numbers refer to the approximate hole diameter
in millimeters. Most ducts can be tested using Range 47.
2.3.2.
Test Blower Min/Max Flows
When depressurizing, the Flex Duct or Flex Duct Adapter must be removed in order to change the
Ranges.
CFM
CFM
Range
Included
minimum maximum
name
115
285
74
yes
48
206
47
yes
17
77
29
yes
6.8
30
18
yes
2.7
12
11
optional
1.1
4.7
7
optional
0.29
1.3
3
optional
0.14
0.49
2
optional
0.05
0.20
1
optional
m3/h
m3/h
minimum maximum
195
485
81
350
29
130
12
51
4.6
20.5
1.8
8.0
0.50
2.2
0.25
0.83
0.09
0.33
Table 2 Minimum and Maximum flows for 441 Range Plugs
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© Retrotec 2017
Range
name
74
47
29
18
11
7
3
2
1
Included
yes
yes
yes
yes
optional
optional
optional
optional
optional
2.4
Digital Gauge
Figure 8: DM32-20A digital gauge.
Systems called 451 come with the DM32 gauge while those called 452 come with the WiFi enabled
gauge. The DM32 and the DM32 WiFi work exactly the same in every other respect except WiFi
Connectivity.
The latest Retrotec Digital Gauge is included with all Retrotec DucTester systems. The gauge is a dualchannel manometer, which can automatically convert the measured Fan Pressure into a range of useful
results that meet every major testing standard in the world.
The gauge can be combined with a calibrated fan for automatic control to Set Pressure in an enclosure,
or to Set Speed. The gauge is also capable of taking a Baseline pressure reading, and automatically
recalculating results, in order to reflect this bias pressure. It can auto zero itself to ensure pressure
readings do not drift away from the true pressure value during a test. It is also capable of displaying
results that are extrapolated to any pressure.
For more information on configuring and using the DM-32, see the DM-32 Operation Manual.
2.5
Flex Duct
Retrotec's duct testing systems US351 and EU351 include a 4" diameter, 12' long flexible duct to
connect the test fan to a register, or duct system. The 250 mm Adapter friction fits over the inlet OR
outlet of the fan to provide a quick means to test in both the depressurize and pressurize directions.
Figure 9: Flex Duct for duct testing system with 10 to 2.5 inch (250 to 63 mm) Adapter.
Page 17 of 79
© Retrotec 2017
2.6
Additional duct testing components
In addition to the calibrated fan and digital dual-channel pressure gauge, a Retrotec DucTester system
includes a few additional items.
2.6.1.
Grill Mask for sealing registers
Grill Mask is used to seal over registers and vents. Grill Mask comes in a 12" wide roll.
It is perforated at 12" intervals to provide easy-to-tear pieces that can seal nearly
anything. Be careful applying Grill Mask to painted surfaces, as paint can be pulled off
when removing it after testing. Grill Mask can be ordered from Retrotec as a single roll
or in three roll bundles. A handy Grill Mask dispenser is also available as an optional
accessory.
2.6.2.
Umbilical for connecting fan and DM32 gauge
An umbilical neatly bundles the needed pressure tubes and Control Cable, to prevent
the user from being greeted by a tangled mess of tubes and cables before each test.
The standard 7 foot (2m) long DucTester umbilical includes a yellow, green, and blue
pressure tube, as well as the Control Cable used for the DM32 to communicate with
the fan.
2.6.3.
Optional 10 to 2.5 (250 to 63 mm) inch adapter
makes it a Model 451
Adapters included have a 10 inch opening on one end that
must fit over the inlet of the Test Blower for
depressurization testing. The inlet end is 2.5 inches which
accepts the 2.5 inch male connector on the flex.
2.6.4.
Duct Connection Flange
Connection Plate, for flex to duct. Female collar on flex slips over
the double seal for fast leak proof connection. Blue connection
point for measuring duct pressure. Tape flange to duct; screws
may be added for additional strength of connection.
2.6.5.
Toolbag keeps all testing components in one place
The Deluxe Cordura Tool bag provides enough volume to hold all the system
components of a DucTester System. It includes a shoulder strap for easy carrying.
The vented exterior pocket is an important feature, useful for storing your smoke
puffer which will destroy your gauge and laptop if stored together.
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2.6.6.
Tubing Accessory Kit
The Tubing Accessory Kit comes with blue, red, yellow and green pressure
tubes approximately 37 ft each, 1/8” inner diameter (11 m each, 3 mm ID), four
short male-to-male pressure tube connectors, two T-connectors for pressure
tubes, a Static Pressure Probe, and a metal tube. Attaching a Static Pressure
Probe to the pressure tube can prevent pressure reading interferences from
wind or other air flows blowing on the pressure tube. The metal tube can be passed through a small
such as under a door or window to prevent the tube from being pinched, and affecting the pressure
reading.
For parts, look at:
http://retrotec.com/products/accessories-parts
.....................................................................................all on the Retrotec website
For more information on these parts, contact:
sales@retrotec.com
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3. Types of Duct Leakage Tests
Locate the step by step Quick Guide that came with your equipment or access it at www.retrotec.com.
Figure 10: DucTester setup, including tubing locations and necessary connections.
In all tests, ducts are first pressurized and the leakage rate measured at a test pressure. In some
geographic areas, that test can be followed by a depressurization test. Readings are usually written
down but may have to be recorded over a prolonged period and the data logged. Retrotec FanTestic
software performs that task and provides a formatted report. Data can be logged automatically or
entered manually.
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4. Prepare for the Duct Leakage Test
4.1
Unpack, connect the gauge to the DucTester
Prior to beginning any test, it is important to verify that the system is functioning properly. Check that
the batteries have enough power, and that the fan can be controlled either automatically or manually.
Model 441 above can be packed as shown.
Model 451 above is a tight fit and needs to be packed in exactly the correct order, or the components
will not fit.
1. Blower with Flow Plug facing to right.
2. Flex with 2 180 bends placed as shown.
3. Gauge case
4. Connector with plate flat on bottom of case. Slide it under the gauge case.
5. Adapter. Additional items may be placed inside Adapter.
6. Fit other components in open spaces.
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Model 451 with the 10 to 2.5 Adapter above can be packed as shown.
4.2
Charge the gauge
The rechargeable batteries should be charged when you get it but leave it on the charger overnight to
make sure. These rechargeables will save you about $300 per year so it’s worth having a charger with
the equipment and one in your vehicle. Battery life is about 11 hours on a single charge with WiFi
disabled. Battery life will last 9 hours on a single charge with WiFi enabled.
The batteries will charge more quickly if the DM32 is turned off, and when plugged to a wall outlet
(instead of to a computer). A large battery icon will be displayed on the screen, as shown below.
Figure 11: The screen of the DM32 while the batteries are being charged.
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4.3
Follow the Quick
Guide that came with
your system
The Quick Guide is intended to walk you
through the test Step by Step. Check it off as
you go. Use this manual for additional
guidance and watch the videos on the
Retrotec website and take the on-line
training course.
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5. Test Procedure – (Steps 1 to 7)
5.1
Step 1 - Prepare the gauge
Once the Gauge has been set up, all settings are restored when the gauge is turned back on.
Appendices C,D and F show specific set up for US, UK and European testers.
□ Home screen must
show Model 450 on
Range 47
If not, tap picture, then tap [Change Device].
Tap ... until “Retrotec DucTester” page appears.
Tap “450”.
Tap the icon with 47 below it to get Range 47
□ Home screen must show
pressure units of CFM, m3/h,
CFM per 100 square feet or
m3/(h*m2).
If not, tap [Settings] and [Result to be displayed].
Tap pressure units until you see “in WC” for
inches of Water Column:
Then tap flow units until you see:
or
Tap On button to return Home.
Once set, you’ll never have to change it again.
□ Home screen must time
average as 5 seconds.
If not, tap [Settings] and [Time Averaging] until “ 5 s
avg” is displayed. Tap On button to return Home.
This will create a running average that will smooth
out results, making them easier to read. If the result
fluctuates, increase up to 30 seconds. Refer to
manual for more information.
The Gauge is set up now and you’re ready for your first test.
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5.2
Step 2 – Determine test criteria and prepare the ducts
How the ducts are prepared will be impacted by the test
pressure and test direction required. Determine the specified
Leakage Class and Test Pressure in order to decide how to break
up the ducts in sections for the test. You will need to have
sufficient blower power to take the ducts up to the specified test
pressure. In other words, you should have enough flow to test
the ducts if they just pass.
Extremely leaky ducts may require much more flow to get them
to the test pressure but that is not needed to see if they fail.
After all it is unfair to provide excessive amounts of flow if you
can determine the ducts will fail anyway. Blowing power is
expensive.
Once you determine the maximum flow you’ll need, use
Table 3 to see if your Model 450 is up to the task.
If Test Pressure is not specified, use a Pressure Class of 1 in WC
except upstream of VAV boxes, use 2 in WC. Use a positive test
pressure unless specified otherwise. Use 1000 Pa in Europe.
Select a limited section of duct that you have sufficient power to test. Measure the duct surface area in
square feet.
Ensure sealing is complete. Ensure sealing materials have cured for the prescribed time or at least 24
hours OR follow manufacturer’s directions.
Blank off and seal the tested ductwork by inserting temporary plugs plates, sheets, balloons, bags into
intentional openings.
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5.3
Step 3 – Connect DucTester to ducts
The DucTester has a 4 inch (100 mm) flex with a 4 inch (100 mm) collar that connects to the duct
system. When considering where to connect the DucTester to the duct system, it is important to think
about airflow restriction and accessibility. Always pressurize first. If you pass and need to test in the
other direction, do so afterwards.
Figure 12 Model 400 Blower set up to test ducts prior to installation of the Flow Plug that is needed to measure flow.
1.
2.
3.
4.
Attach the 4 inch (100 mm) Flange to the ductwork.
Attach 4 inch (100 mm) collar on flex to flange.
Connect DucTester exhaust to flex with the 2.5 inch (63mm) connector.
Install Range 47 Flow Plug. Range 47 provides 52 to 206 CFM, which is sufficient to test most
duct runs. Refer to Table Minimum and Maximum flows for all Range Plugs.
5.3.1.
Select a test direction
Duct leakage can be measured by blowing air into the ducts to pressurize the ducts, or by pulling air out
of the ducts to depressurize the ducts. Program guidelines may specify a particular test direction but
generally in the USA ducts are pressurized only and in Europe they are tested in both directions. Both
test directions provide similar results, however pressurization testing is faster.
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5.3.2.
Setting up for pressurization
The advantage of pressurizing is that it makes
changing Range Rings on the fan easier so always
test in this direction first. Simply install the Flex
Duct on the outlet side of the Blower. Wiggle the
fitting inside the rubber collar on the Blower
Housing.
5.3.3.
Setting up for depressurization
Install Range 47, since most systems can be tested on this Range Configuration. For more information
about selecting and changing Range Configurations, refer to section xx. Install the Flex Duct over the fan
inlet, covering the Range Rings and tighten the strap.
Figure 13: Install Flex Duct over the fan inlet, covering the Range Rings, for depressurization. Later systems have a 2.5 inch
connector instead of the 4 inch (100 mm) shown.
5.3.4.
Install Range Configuration on fan
Each Retrotec Model 400 Blower includes four Range Configurations to maximize accuracy and
versatility: Range 74, 47, 29 and 18 as standard. The selected Range Configuration will determine the
range of air flow that the DucTester can measure.
While it is easy to change the Range Configuration when pressurizing, it is better to make your best
guess at the correct Range Configuration when testing in the depressurization direction since the Flex
Duct Adapter must be removed to change Range Configurations. The Flow Plugs must always go on the
inlet of the fan.
Use a Range with a larger opening for leakier ducts and smaller opening for tighter ducts. Testing should
always be done at the highest possible fan speed, which means using the most restrictive Range
Configuration possible (the one with the smallest hole possible). Higher fan speeds lead to the highest
degree of accuracy. If the fan is running too slowly, “-----“will appear on the DM32 gauge display
indicating you must change to a more restrictive range.
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Figure 14: Inserting a Flow Plug into the end plate.
5.4 Step 4 –Tubing, control and power connections
If the rechargeable batteries in the DM32 are below one quarter power during a test, the battery
charger should be connected to the micro-USB port on the DM32. Always charge them fully overnight.
Connect yellow and green tubes between DucTester and gauge. Often, the yellow, green and blue tubes
and the Control Cable are left permanently connected to the gauge but if not, make those connections.
Figure 15: Pressure ports on the top of the gauge are color-coded to match the tubing
Connect blue tube to gauge and to ducts using static probe or
connection on flange. In duct systems that are relatively tight (200
CFM or less), the induced test pressure in the system is uniform, and
all locations will provide similar results.
Figure 16: A Static Pressure Probe attached to a
pressure tube allows the measurement of
pressure without disturbances due to turbulence.
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Plug in the Speed Control Cable between DucTester and Gauge. Connect the Control Cable to the fan,
unless you wish to use the Manual Speed Control Knob. When the Control Status light is illuminated
solid green, this means the fan is connected to the gauge and is ready to perform automated testing.
Having the Speed Control Cable connected disables the manual Speed Control Knob. To enable the
manual Speed Control Knob, disconnect the yellow Speed Control Cable and turn the knob on, off and
on again.
Figure 17: Electrical connections on the bottom of the gauge include Network (Ethernet) Cable that goes from the DM32 to a
PC (if Retrotec PC software is used for data collection), micro USB cable for PC software and/or charging, and a reset button.
Plug in to power source. Ensure the power switch is Off which means speed control is set to 0. Connect
the power cord to a wall outlet and to the fan. The Mains Power status light turns green, indicating
power is connected. Before connecting the Control Cable, the manual speed control knob can be used
to test run the fan. If the Control Cable is connected it must be disconnected to use the Manual Speed
Control Knob. The Manual Speed Control Knob must be turned to zero and back on again to re-activate
it.
Figure 18: Model 300 Fan Top with power cord, color-coded tubing connections (green and yellow) and Control Cable.
Model 400 is the same except the power comes in on the other side of the Blower Housing
.
To test control of the fan, press [Set Speed] [1] [Set] on the DM32. This sets the fan to 1% speed on the
gauge but achieves about 15% speed on the blower.
Do not use [Set Pressure] since this control has not been linearized and it will oscillate. Future models
will have a fix for this.
Press [Stop] to stop the fan.
For details on DM32 operation, see DM32 manual.
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5.5 Step 5 – Set up Test Pressure and Area in Gauge
Default in gauge must match the specified Test Pressure. If not, tap [Settings]
and
to advance to:
Then,”Default @ Pressure”
and [Set] value to specified Test Pressure.
Since you must not exceed the test pressure, the actual pressure will be lower but entering this default
will ensure that all flow results are displayed as a value extrapolated to the exact test pressure entered.
Measure the duct surface area in square feet and enter it into the DM32. Select a limited section of
duct for which the estimated leakage will not exceed the capacity of the test apparatus. Area can also
be accessed from [Settings].
[Area] then use the number pad and tap [Set].
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5.6 Step 6 – Run Test Blower to Measure the Leakage
Running the blower requires adjusting the speed from low to high to avoid damage to ducts. Always
start by pressurizing since it’s easier to change ranges in this configuration and ducts are stronger under
positive pressure. Usually, the same result will be achieved in each test direction
Tap [Set Speed] on the Home screen and [1] on the number pad to
achieve 1% Blower speed. Since this unit as of 2015-04-02 has not yet
been linearized, 1% actually represents closer to 10% of maximum speed.
If well below your desired test pressure, tap the jog arrow.
WARNING – if 5% is displayed on the Up / Down Jog keys, update your
firmware online by downloading and operating the Configurator. Your
gauge will not function correctly if you have the old 5% Jog function.
To prevent over-pressurizing, slowly increase fan speed using Set Speed.
If the pressure increments are too large, Tap [Set Speed], 1.2% for
example to get a smaller increase in flow rate. Otherwise Jog the speed
up 1% at a time until a CFM value appears on the display. Continue to
increase fan speed up to but do not exceed the Pressure Class. If you do not reach the Pressure Class,
results will still be calculated at that Pressure Class.
Tap “@” on the display to get flow at the Default pressure set earlier. This will give a result at the exact
Test Pressure entered even though you might be slightly below it which is preferred. Or above which is
not preferred. Once close to your desired test speed, when “@” is displayed, the flow will vary very
little as speed is changed.
5.7 Step 7 – Test Passes
Complete the test reports and, if required, obtain witness’s signature. Use Retrotec’s FanTestic
Software to generate a report automatically. You can edit a template to add logos and other details that
will print out each time you complete a test. In minutes.
Remove temporary blanks and seals. Restore ducts to pre-test conditions after testing is complete.
Notice the conditions in the building upon arrival and be sure to restore it to that condition before
leaving.
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6. Troubleshooting
Occasionally simple problems do occur with a DucTester system. If the problem is described in any of
the following sections, follow the steps to attempt to resolve the problem. If the problem persists,
contact support@retrotec.com.
6.1
If test fails
If you can create 0.1 In WC (25 Pa), the DM32 or the software will still give an accurate result. There is
usually no need to achieve the test pressure if the ducts will still fail. First check all seals and
connections for leaks. Use a positive pressure and survey all sections of ducts with your hands if you
have access. To increase the sensitivity, wet your hands. If ductwork is hard to reach, you can use
smoke inside the duct to locate the leak but this can be messy.
If it fails, additional sealing is needed.
6.2
If no Results are displayed (“--” appears on display)
Backpressure refers to the pressure that the DucTester fan works against while running. Under most
testing conditions, backpressure is not a concern. If the backpressure is too great, the DM32 gauge will
automatically sense it and display “--“, indicating the fan pressure signal is too low compared to the
pressure the fan is working against. Changing to a more restrictive Range Configuration will solve this
problem.
If the target pressure has been reached, but “--“ appears as a flow reading, the fan is running too slowly
to measure flow. Perform the following to get a duct leakage result:
1.
1.
2.
Add the next smaller Range Ring.
Change Range Configuration on the gauge to match the Range Ring installed on the fan.
Re-adjust DucTester fan speed.
If the Range Ring installed is the smallest hole, there are no more Range Rings to install, and “--“still
appears:
1.
2.
3.
4.
Make sure Range Configuration on the gauge actually matches the installed Range Ring.
Check that the blue tube is connected to the gauge and then check that it is reading pressure – put a
finger on the open end of the blue tube and ensure that the Channel A pressure reading changes. If it
does not, then the tube is blocked or pinched.
Check that there is no blockage in the ducts between the DucTester and the register containing the
blue tube. To do this, move the blue tube to a different section of duct and compare the reading on
Channel A to the original reading. If the pressures in the two locations are not similar, there may be
blockage in the duct system that needs to be removed.
Check that the DucTester is actually reading properly on Channel B. To do this, remove the flex duct to
provide more leakage to get a reading. If the flow still reads “--” then the yellow or green tubes could
be blocked or disconnected.
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6.3
Cannot achieve test pressure
If the Test Blower reaches 100% speed on the “Range 74” Range Ring before reaching the target
pressure, the fan is not providing enough air flow to reach the target pressure. Look for large
disconnects in the duct system by pressurizing the ducts then use your hand to find leaks.
If that fails, use the @ feature to read the flow that would
occur if you reached the desired test pressure. Set the @
by tapping [Settings} then [Default @ Pressure]. Set to the
desired test pressure.
6.4
Gauge “Flow” reading does not change? Turn off [@]
When the measured flow or fan pressure does not increase as fan speed increases the
gauge has likely been set to calculate a value for result extrapolation. To remove result
extrapolation, press the [@] button until “is Off” is shown.
If [@] is active, the gauge calculates a reading for flow at the extrapolation pressure, no matter what the
actual “PrA” measures. Therefore, regardless of fan speed, the measured flow will appear relatively
unchanging.
6.5
Fan does not run
Make sure the power light is on and the power switch is set to “1”. If the yellow Speed Control Cable
(Ethernet-style) has been connected previously to a gauge, the Speed Control Knob must be turned off
and then on again. This is a fail-safe feature so the fan does not go on unless you want it to.
Alternatively, turning the power switch off and back on will activate the Speed Control Knob as long as
the Speed Control Cable is not connected.
6.6
Avoid common mistakes
The following mistakes are commonly made when performing a duct test, and can significantly affect
the results.
•
•
•
•
•
Wrong Range Configuration and or wrong Device selected on gauge
Water in tube, pinched tube
No green reference tube attached while depressurizing ducts
Not covering all intentional duct openings
Tape sealing being blown off, usually happens in pressurization
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7. Find duct leaks
Locating leaks in the ducts can be a tricky process, and there are a number of methods that are used.
7.1
Using a smoke puffer
Smoke puffers work similarly to theatrical smoke for finding leaks, but on a much smaller scale. The
chemical smoke of Retrotec’s Air Current Tester is the same density as air, and therefore does not move
unless there is air movement. Puff out a small amount of smoke near suspected leaks, (for example,
near joints, or in front of registers), while the DucTester is connected to the ducts and running, and
notice the smoke either being blown away or being sucked in, depending on the direction of the test.
7.2
Using theatrical smoke
The use of theatrical smoke can be a very effective way to find leaks in a duct system. A theatrical
smoke machine is used to inject non-toxic chemical smoke through the DucTester fan, and into the duct
system. Walking around to check the duct systems will point out obvious leak locations where smoke
appears. This can help find hard-to-detect leaks in attics and crawlspaces. Using this type of detection is
called theatrical for a reason – it is quite a sight to see for homeowners and builders.
Caution: Make sure not to inject the smoke directly into the fan motor, but instead into the edge of the
fan housing. Also, make sure to clean any residue away from the flow sensors, motor and fan housing
when the show is over. The particles can block the sensors needed for measurements.
7.3
Using an infrared camera
An infrared camera can graphically display areas where cold air is infiltrating into a building or building,
or show from the outside, where hot air is exfiltrating. The camera can also show zones that are poorly
insulated, and would otherwise be invisible without opening up wall sections.
7.4
Using a wet hand
Sometimes, a damp hand is more than enough to feel the movement of air around a leak. Wet skin will
feel cool or cold in the path of moving air.
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8. Field Check the DucTester to find out what is not working
Standard procedure says you calibrate your gauges every year or two, but does this really make sense?
The gauge can be calibrated regularly but when did the gauge go out of calibration? Last week or last
year?
There is a quick way to field-check your gauge regularly or before an important test. Gauge calibration,
where errors are typically a few %, is not as frequent a cause of problems when compared to blocked,
leaking or pinched tubes that happen more often and can yield errors of 10 or 90%. Sending your gauge
in for calibration does not address those problems but doing a field check will.
8.1
Field Check the gauge
To verify the calibration of a gauge, the easiest method is to compare the readings of one channel with
respect to the other channel. If the pressures are equal, then it is likely the gauge is accurate, because
the chance of both channels being out of calibration by the same amount is very small.
To perform a cross port check
Download the Pressure Gauge Operation Manual for DM32 from:
http://retrotec.com/sites/default/files/manual-guides-specs/Manual-DM32%20Operation.pdf
and look at the Section named “Verify your gauge accuracy between factory calibrations”.
You will also Field Check the tubes using the procedure outlined there.
This test requires one color of tube be connected between channel A and B. If both channels don’t
display the same pressure or the pressure drops rapidly the tubes are blocked or leaking. Water can be
whipped or blown out of tubes and crimped tubes can be adjusted.
If the readings are different, either one tube is blocked or the gauge is faulty. Try another tube to see if
it’s the tube or the gauge. Check each tube separately. If differences on the gauge persist with different
tubes connected, repeat the test against another gauge. Only then should a gauge return be
considered.
Pressure dropping to zero in 10 seconds or less indicates a leak somewhere; try another tube and try the
same tube on a different port to see which piece is faulty, the tube or the gauge. If the tube end is
damaged, slice 1/8 inch off the tube and try again.
The tubes have now all been checked, removing that major source of error.
8.2
Field Check the DucTester as a system
This check will ensure that the DucTester is connected properly, and will ensure that the measured
results for flow are within 10% of the true value when using the DucTester as a system with Flex Duct. a
temporary one can be easily manufactured using thin, solid, cardboard or metal with a 2" x 2" square
hole (4 sq in) cut in the center. If making your own, a 1/4 inch diameter hole should be made in one
corner of the plate, as far away from the larger hole as possible, into which the blue tube can be
inserted.
To field check the DucTester calibration
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1.
2.
3.
4.
5.
6.
Tape the Field Calibration Plate to the Flex Duct Flange, and attach the blue tube to the pressure
pickup (or into the small cut hole if using a homemade one).
Install Range 74 Flow Plug and set same Range on the Gauge.
Attach the Flex Duct to the outlet side of the fan to pressurize the Flex Duct. If depressurizing ducts
normally, you can also check the DucTester in that direction by attaching the flex to the inlet of the fan
where you must connect the green reference tube.
Stretch the Flex Duct to its full length. Set the “Mode” to “Flow”.
Set % Speed until 1 in WC (250 Pa) is reached. The flow should read 68 CFM (32 l/s)
Compare this value with the reading on the DucTester.
The calibrated fan and flex duct has now been checked as a system, removing that major source of
error.
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Appendix A
Flow Conversion Tables
Table 4: Flow in CFM for various fan pressures, Retrotec 400 series fans
*When Range 74 is used with 10-4” adapter on fan inlet, i.e. fan is depressurizing duct and Channel A is negative
Fan Pressure
Pa
In WC
250
Range
74
74*
47
29
18
11
7
3
2
1
1.0
114.7
113.0
49.6
17.2
6.79
2.69
1.06
0.294
---
---
275
1.1
120.4
118.6
51.9
18.0
7.12
2.82
1.11
0.310
---
---
300
1.2
125.8
123.9
54.2
18.8
7.43
2.95
1.16
0.325
---
---
325
1.3
131.0
129.0
56.4
19.6
7.73
3.07
1.21
0.340
---
---
350
1.4
136.0
133.9
58.4
20.3
8.03
3.19
1.25
0.354
0.145
0.054
375
1.5
140.8
138.7
60.4
21.1
8.31
3.30
1.29
0.368
0.150
0.056
400
1.6
145.5
143.3
62.4
21.7
8.58
3.41
1.34
0.381
0.156
0.058
425
1.7
150.0
147.7
64.2
22.4
8.84
3.51
1.38
0.394
0.161
0.060
450
1.8
154.4
152.0
66.1
23.1
9.10
3.61
1.42
0.407
0.166
0.062
475
1.9
158.6
156.2
67.8
23.7
9.35
3.71
1.46
0.420
0.170
0.064
500
2.0
162.8
160.3
69.5
24.3
9.59
3.81
1.50
0.432
0.175
0.066
525
2.1
166.8
164.3
71.2
24.9
9.83
3.91
1.53
0.443
0.180
0.068
550
2.2
170.8
168.2
72.9
25.5
10.1
4.00
1.57
0.455
0.184
0.070
575
2.3
174.7
172.1
74.5
26.1
10.3
4.09
1.60
0.466
0.189
0.072
600
2.4
178.5
175.8
76.0
26.6
10.5
4.18
1.64
0.478
0.193
0.073
625
2.5
182.2
179.4
77.5
27.2
10.7
4.26
1.67
0.488
0.197
0.075
650
2.6
185.8
183.0
79.0
27.7
10.9
4.35
1.71
0.499
0.201
0.077
675
2.7
189.4
186.6
80.5
28.2
11.1
4.43
1.74
0.510
0.205
0.078
700
2.8
192.9
190.0
82.0
28.7
11.3
4.51
1.77
0.520
0.209
0.080
725
2.9
196.3
193.4
83.4
29.3
11.5
4.59
1.80
0.530
0.213
0.082
750
3.0
199.7
196.7
84.8
29.8
11.7
4.67
1.83
0.540
0.217
0.083
775
3.1
203.1
200.0
86.1
30.2
11.9
4.75
1.86
0.550
0.221
0.085
800
3.2
206.3
203.2
87.5
30.7
12.1
4.83
1.89
0.560
0.225
0.086
825
3.3
209.6
206.4
88.8
31.2
12.3
4.90
1.92
0.570
0.228
0.088
850
3.4
212.8
209.6
90.1
31.7
12.5
4.97
1.95
0.579
0.232
0.089
875
3.5
215.9
212.6
91.4
32.1
12.7
5.05
1.98
0.589
0.236
0.091
900
3.6
219.0
215.7
92.6
32.6
12.9
5.12
2.01
0.598
0.239
0.092
925
3.7
222.0
218.7
93.9
33.0
13.0
5.19
2.03
0.607
0.243
0.093
950
3.8
225.0
221.7
95.1
33.5
13.2
5.26
2.06
0.616
0.246
0.095
975
3.9
228.0
224.6
96.3
33.9
13.4
5.33
2.09
0.625
0.250
0.096
1000
4.0
230.9
227.5
97.5
34.3
13.6
5.40
2.12
0.634
0.253
0.098
1025
4.1
233.8
230.3
98.7
34.8
13.7
5.46
2.14
0.642
0.256
0.099
1050
4.2
236.7
233.1
99.9
35.2
13.9
5.53
2.17
0.651
0.260
0.100
1075
4.3
239.5
235.9
101.0
35.6
14.1
5.60
2.19
0.660
0.263
0.102
1100
4.4
242.3
238.7
102.2
36.0
14.2
5.66
2.22
0.668
0.266
0.103
1125
4.5
245.1
241.4
103.3
36.4
14.4
5.73
2.24
0.676
0.269
0.104
Page 37 of 79
© Retrotec 2017
Fan Pressure
Pa
In WC
1150
Range
74
74*
47
29
18
11
7
4.6
247.8
244.1
104.4
36.8
14.5
5.79
2.27
0.685
0.272
0.106
1175
4.7
250.5
246.7
105.5
37.2
14.7
5.85
2.29
0.693
0.275
0.107
1200
4.8
253.2
249.4
106.6
37.6
14.8
5.91
2.32
0.701
0.279
0.108
1225
4.9
255.8
252.0
107.7
38.0
15.0
5.98
2.34
0.709
0.282
0.109
1250
5.0
258.4
254.6
108.8
38.4
15.2
6.04
2.37
0.717
0.285
0.111
1275
5.1
261.0
257.1
109.8
38.8
15.3
6.10
2.39
0.725
0.288
0.112
1300
5.2
263.6
259.7
110.9
39.1
15.5
6.16
2.41
0.733
0.291
0.113
1325
5.3
266.2
262.2
111.9
39.5
15.6
6.22
2.44
0.741
0.294
0.114
1350
5.4
268.7
264.7
112.9
39.9
15.7
6.28
2.46
0.748
0.296
0.116
1375
5.5
271.2
267.1
113.9
40.3
15.9
6.33
2.48
0.756
0.299
0.117
1400
5.6
273.7
269.6
114.9
40.6
16.0
6.39
2.50
0.764
0.302
0.118
1425
5.7
276.1
272.0
115.9
41.0
16.2
6.45
2.53
0.771
0.305
0.119
1450
5.8
278.5
274.4
116.9
41.3
16.3
6.50
2.55
0.779
0.308
0.120
1475
5.9
281.0
276.7
117.9
41.7
16.5
6.56
2.57
0.786
0.311
0.121
1500
6.0
283.3
279.1
118.9
42.0
16.6
6.62
2.59
0.793
0.314
0.123
1525
6.1
285.7
281.4
119.8
42.4
16.7
6.67
2.61
0.801
0.316
0.124
1550
6.2
288.1
283.8
120.8
42.7
16.9
6.73
2.64
0.808
0.319
0.125
1575
6.3
290.4
286.1
121.7
43.1
17.0
6.78
2.66
0.815
0.322
0.126
1600
6.4
292.7
288.3
122.7
43.4
17.1
6.83
2.68
0.822
0.324
0.127
1625
6.5
295.0
290.6
123.6
43.8
17.3
6.89
2.70
0.829
0.327
0.128
1650
6.6
297.3
292.8
124.5
44.1
17.4
6.94
2.72
0.836
0.330
0.129
1675
6.7
299.6
295.1
125.5
44.4
17.5
6.99
2.74
0.843
0.332
0.130
1700
6.8
301.8
297.3
126.4
44.8
17.7
7.05
2.76
0.850
0.335
0.131
1725
6.9
304.0
299.5
127.3
45.1
17.8
7.10
2.78
0.857
0.338
0.133
1750
7.0
306.3
301.7
128.2
45.4
17.9
7.15
2.80
0.864
0.340
0.134
1775
7.1
308.5
303.8
129.1
45.7
18.1
7.20
2.82
0.871
0.343
0.135
1800
7.2
310.6
306.0
129.9
46.0
18.2
7.25
2.84
0.878
0.345
0.136
1825
7.3
312.8
308.1
130.8
46.4
18.3
7.30
2.86
0.884
0.348
0.137
1850
7.4
315.0
310.2
131.7
46.7
18.4
7.35
2.88
0.891
0.350
0.138
1875
7.5
312.4
132.6
47.0
18.6
7.40
2.90
0.898
0.353
0.139
1900
7.6
314.4
133.4
47.3
18.7
7.45
2.92
0.904
0.355
0.140
1925
7.7
316.5
134.3
47.6
18.8
7.50
2.94
0.911
0.358
0.141
1950
7.8
135.1
47.9
18.9
7.55
2.96
0.917
0.360
0.142
1975
7.9
136.0
48.2
19.0
7.60
2.98
0.924
0.363
0.143
2000
8.0
136.8
48.5
19.2
7.64
2.99
0.930
0.365
0.144
2025
8.1
137.6
48.8
19.3
7.69
3.01
0.937
0.368
0.145
2050
8.2
138.5
49.1
19.4
7.74
3.03
0.943
0.370
0.146
2075
8.3
139.3
49.4
19.5
7.79
3.05
0.950
0.372
0.147
2100
8.4
140.1
49.7
19.6
7.83
3.07
0.956
0.375
0.148
2125
8.5
140.9
50.0
19.8
7.88
3.09
0.962
0.377
0.149
2150
8.6
141.7
50.3
19.9
7.93
3.10
0.968
0.379
0.150
Page 38 of 79
© Retrotec 2017
3
2
1
Fan Pressure
Pa
In WC
2175
Range
47
29
18
11
7
8.7
142.5
50.6
20.0
7.97
3.12
0.975
0.382
0.151
2200
8.8
143.3
50.9
20.1
8.02
3.14
0.981
0.384
0.152
2225
8.9
144.1
51.2
20.2
8.06
3.16
0.987
0.386
0.153
2250
9.0
144.9
51.5
20.3
8.11
3.18
0.993
0.389
0.154
2275
9.1
145.7
51.8
20.4
8.16
3.19
1.00
0.391
0.155
2300
9.2
146.4
52.0
20.5
8.20
3.21
1.01
0.393
0.156
2325
9.3
147.2
52.3
20.7
8.24
3.23
1.01
0.395
0.157
2350
9.4
148.0
52.6
20.8
8.29
3.25
1.02
0.398
0.158
2375
9.5
148.8
52.9
20.9
8.33
3.26
1.02
0.400
0.158
2400
9.6
149.5
53.2
21.0
8.38
3.28
1.03
0.402
0.159
2425
9.7
150.3
53.4
21.1
8.42
3.30
1.04
0.404
0.160
2450
9.8
151.0
53.7
21.2
8.46
3.31
1.04
0.407
0.161
2475
9.9
151.8
54.0
21.3
8.51
3.33
1.05
0.409
0.162
2500
10.0
152.5
54.2
21.4
8.55
3.35
1.05
0.411
0.163
2525
10.1
153.3
54.5
21.5
8.59
3.37
1.06
0.413
0.164
2550
10.2
154.0
54.8
21.6
8.64
3.38
1.06
0.415
0.165
2575
10.3
154.7
55.1
21.7
8.68
3.40
1.07
0.417
0.166
2600
10.4
155.5
55.3
21.8
8.72
3.41
1.08
0.420
0.167
2625
10.5
156.2
55.6
22.0
8.76
3.43
1.08
0.422
0.168
2650
10.6
156.9
55.8
22.1
8.80
3.45
1.09
0.424
0.169
2675
10.7
157.7
56.1
22.2
8.85
3.46
1.09
0.426
0.169
2700
10.8
158.4
56.4
22.3
8.89
3.48
1.10
0.428
0.170
2725
10.9
159.1
56.6
22.4
8.93
3.50
1.10
0.430
0.171
2750
11.0
159.8
56.9
22.5
8.97
3.51
1.11
0.432
0.172
2775
11.1
160.5
57.1
22.6
9.01
3.53
1.12
0.434
0.173
2800
11.2
161.2
57.4
22.7
9.05
3.54
1.12
0.436
0.174
2825
11.3
161.9
57.7
22.8
9.09
3.56
1.13
0.438
0.175
2850
11.4
162.6
57.9
22.9
9.13
3.58
1.13
0.441
0.176
2875
11.5
163.3
58.2
23.0
9.17
3.59
1.14
0.443
0.176
2900
11.6
164.0
58.4
23.1
9.21
3.61
1.14
0.445
0.177
2925
11.7
164.7
58.7
23.2
9.25
3.62
1.15
0.447
0.178
2950
11.8
165.4
58.9
23.3
9.29
3.64
1.15
0.449
0.179
2975
11.9
166.0
59.2
23.4
9.33
3.65
1.16
0.451
0.180
3000
12.0
166.7
59.4
23.5
9.37
3.67
1.16
0.453
0.181
3025
12.1
167.4
59.7
23.6
9.41
3.68
1.17
0.455
0.181
3050
12.2
168.1
59.9
23.7
9.45
3.70
1.18
0.457
0.182
3075
12.3
168.7
60.1
23.8
9.49
3.71
1.18
0.459
0.183
3100
12.4
169.4
60.4
23.9
9.53
3.73
1.19
0.461
0.184
3125
12.5
170.1
60.6
23.9
9.56
3.74
1.19
0.463
0.185
3150
12.6
170.7
60.9
24.0
9.60
3.76
1.20
0.465
0.186
3175
12.7
171.4
61.1
24.1
9.64
3.77
1.20
0.466
0.186
Page 39 of 79
© Retrotec 2017
74
74*
3
2
1
Fan Pressure
Pa
In WC
3200
Range
47
29
18
11
7
12.8
172.1
61.4
24.2
9.68
3.79
1.21
0.468
0.187
3225
12.9
172.7
61.6
24.3
9.72
3.80
1.21
0.470
0.188
3250
13.0
173.4
61.8
24.4
9.76
3.82
1.22
0.472
0.189
3275
13.1
174.0
62.1
24.5
9.79
3.83
1.22
0.474
0.190
3300
13.2
174.7
62.3
24.6
9.83
3.85
1.23
0.476
0.191
3325
13.3
175.3
62.5
24.7
9.87
3.86
1.23
0.478
0.191
3350
13.4
175.9
62.8
24.8
9.90
3.88
1.24
0.480
0.192
3375
13.5
176.6
63.0
24.9
9.94
3.89
1.24
0.482
0.193
3400
13.6
177.2
63.2
25.0
10.0
3.91
1.25
0.484
0.194
3425
13.7
177.9
63.5
25.1
10.0
3.92
1.25
0.486
0.195
3450
13.8
178.5
63.7
25.2
10.1
3.93
1.26
0.487
0.195
3475
13.9
179.1
63.9
25.3
10.1
3.95
1.26
0.489
0.196
3500
14.0
179.7
64.2
25.3
10.1
3.96
1.27
0.491
0.197
3525
14.1
180.4
64.4
25.4
10.2
3.98
1.27
3550
14.2
181.0
64.6
25.5
10.2
3.99
1.28
3575
14.3
181.6
64.8
25.6
10.2
4.01
1.28
3600
14.4
182.2
65.1
25.7
10.3
4.02
1.29
3625
14.5
182.9
65.3
25.8
10.3
4.03
1.29
3650
14.6
183.5
65.5
25.9
10.3
4.05
1.30
3675
14.7
184.1
65.7
26.0
10.4
4.06
1.30
3700
14.8
184.7
66.0
26.1
10.4
4.08
1.31
3725
14.9
185.3
66.2
26.1
10.4
4.09
1.31
3750
15.0
185.9
66.4
26.2
10.5
4.10
1.32
3775
15.2
186.5
66.6
26.3
10.5
4.12
3800
15.3
187.1
66.8
26.4
10.6
4.13
3825
15.4
187.7
67.1
26.5
10.6
4.14
3850
15.5
188.3
67.3
26.6
10.6
4.16
3875
15.6
188.9
67.5
26.7
10.7
4.17
3900
15.7
189.5
67.7
26.7
10.7
4.18
3925
15.8
190.1
67.9
26.8
10.7
4.20
3950
15.9
190.7
68.2
26.9
10.8
4.21
3975
16.0
191.3
68.4
27.0
10.8
4.22
4000
16.1
191.9
68.6
27.1
10.8
4.24
4025
16.2
192.4
68.8
27.2
10.9
4.25
4050
16.3
193.0
69.0
27.3
10.9
4.26
4075
16.4
193.6
69.2
27.3
10.9
4.28
4100
16.5
194.2
69.4
27.4
11.0
4.29
4125
16.6
194.8
69.6
27.5
11.0
4.30
4150
16.7
195.3
69.9
27.6
11.0
4.32
4175
16.8
195.9
70.1
27.7
11.1
4.33
4200
16.9
196.5
70.3
27.8
11.1
4.34
Page 40 of 79
© Retrotec 2017
74
74*
3
2
1
Fan Pressure
Pa
In WC
4225
Range
74
74*
47
29
18
11
7
17.0
197.0
70.5
27.8
11.1
4.36
4250
17.1
197.6
70.7
27.9
11.2
4.37
4275
17.2
198.2
70.9
28.0
11.2
4.38
4300
17.3
198.7
71.1
28.1
11.2
4.39
4325
17.4
199.3
71.3
28.2
11.3
4.41
4350
17.5
199.9
71.5
28.2
11.3
4.42
4375
17.6
200.4
71.7
28.3
11.3
4.43
4400
17.7
201.0
71.9
28.4
11.4
4.44
4425
17.8
201.5
72.1
28.5
11.4
4.46
4450
17.9
202.1
72.3
28.6
11.4
4.47
4475
18.0
202.7
72.5
28.6
11.5
4.48
4500
18.1
203.2
72.7
28.7
11.5
4.49
4525
18.2
203.8
72.9
28.8
11.5
4.51
4550
18.3
204.3
73.1
28.9
11.6
4.52
4575
18.4
204.8
73.3
29.0
11.6
4.53
4600
18.5
205.4
73.5
29.0
11.6
4.54
4625
18.6
205.9
73.7
29.1
11.6
4.56
4650
18.7
206.5
73.9
29.2
11.7
4.57
4675
18.8
207.0
74.1
29.3
11.7
4.58
4700
18.9
207.6
74.3
29.4
11.7
4.59
4725
19.0
208.1
74.5
29.4
11.8
4.61
4750
19.1
208.6
74.7
29.5
11.8
4.62
4775
19.2
209.2
74.9
29.6
11.8
4.63
4800
19.3
209.7
75.1
29.7
11.9
4.64
4825
19.4
210.2
75.3
29.7
11.9
4.65
4850
19.5
210.8
75.5
29.8
11.9
4.67
4875
19.6
211.3
75.7
29.9
12.0
4.68
4900
19.7
211.8
75.9
30.0
12.0
4.69
4925
19.8
212.4
76.1
30.1
12.0
4.70
4950
19.9
212.9
76.3
30.1
12.1
4.71
4975
20.0
213.4
76.5
30.2
12.1
4.73
3
2
1
The Flow Calibration Equations used to create this were generated using an ISO 17025 Accredited Flow Chamber to
calibrated a Model 400 Fan.
Page 41 of 79
© Retrotec 2017
Appendix B
U.S. Duct Leakage - Calculation (SMACNA)
When testing, these factors may have to be calculated prior to the test. In some cases, this calculation is
done by the design engineer so the tester only has to supply leakage values.
B.1
Leakage Class
Leakage Class, CL
CL = F / P 0.65
CL = F (leakage rate in CFM/ 100 sq ft) divided by the Pressure in in WC to the 0.65
Power.
Leakage Constant is an equivalent term.
Leakage classification identifies a permissible leakage rate in CFM per 100 square feet of duct surface
according to the relationship CL = F / P 0.65.
F is the leakage factor, a rate in CFM/100 sq ft of duct surface area and varies with pressure.
P is the pressure.
CL is the Leakage Class
If, at the specified test pressure, the leakage factor (F), by test, is lower than or equal to that associated
with the specified leakage class, the duct is in compliance. Alternatively, if the leakage constant (CL)
determined from tests is lower than or equal to the specified leakage class, the duct is in compliance.
Assignment of leakage classes involves careful consideration of system size, duct location, sealing and
construction class. Arbitrary assignment of an allowable % of leakage in disregard of these factors can
require unobtainable results.
A ½% allowance, for example, on a 3900 CFM system with 1300 sq ft of duct or on a 39,000 CFM system
with 13,000 sq ft of duct would mean an unrealistic leakage factor of 1.5 CFM/100 sq ft in each case.
Similarly, arbitrary assignment of 10″ wg class construction for a system operating at 1″ wg in order to
get leak class 3 rectangular duct would not be cost effective. Assigning a leakage class 3 to a 1″ wg
rectangular duct system may address an achievable result but the associated difficulty and costs will be
excessive.
SMACNA Table 4-1 Leakage Class, 1985 version
Duct Construction Class
Seal Class
Sealing applicable
½″, 1″, 2″ wg
3″ wg
4″, 6″, 10″ wg
C
B
A
Transverse joints only
All transverse joints and
longitudinal seams only
All transverse joints, longitudinal
seams, and duct to wall penetrations
Leakage Class
Rectangular metal
24
12
6
Round metal
12
6
3
Table 5 SMACNA 1985 Leakage Class
SMACNA Table 4-1 (reproduced here) represents the leakage expected using Seal Classes A, B, and C as
indicated on duct construction of the types typically selected for each pressure class. Conceivably Seal
Page 42 of 79
© Retrotec 2017
Class B or A could be applied at construction pressure classes lower than indicated in SMACNA Table 4-1.
However, unless joint type, seam type, duct wall thickness and specific sealing method were already
collectively prequalified by tests (or by an acceptable experience record at a higher pressure) leakage
rate is less predictable. The benefits of setting allowable leakage rates lower than shown in SMACNA
Table 4-1 should be carefully weighed against the costs of achieving them.
SMACNA Table 4-1 Leakage Class, 2012 version
Duct Construction Class
Seal Class
Sealing applicable
½″, 1″, 2″ wg
3″ wg
4″, 6″, 10″ wg
C
B
A
Transverse joints only
All transverse joints and
longitudinal seams only
All transverse joints, longitudinal
seams, and duct to wall penetrations
Leakage Class
Rectangular metal
16
8
4
Round metal
8
4
2
Table 6 SMACNA 2012 Leakage Class
1. Leakage classes in SMACNA Table 4-1 apply when the designer does not designate other
limits and has specified Seal Class C for ½″ and 1″ wg See text on sealing in the HVAC-DCS
manual.
2. Unsealed rectangular metal duct may follow Leakage Class 48.
3. Fibrous glass duct may follow Leakage Class 6 (at 2″ wg or less).
4. Unsealed flexible duct leakage average is estimated to be Class 30. Sealed nonmetal flexible
duct is an average of Class 12.
5. See SMACNA HVAC Duct Systems Design Manual Table 5-1 for longitudinal seam leakage
rates.
6. Although Seal Class A or B might be assigned for lower pressures, the leakage class may not
conform to those associated with the higher pressure. Other construction details influence
results.
7. The duct pressure classification is not the fan static pressure nor the external static pressure
(on an HVAC unit) unless the system designer has made such an assignment in his contract
documents. Unless construction class is otherwise specified it means a static pressure
classification in the SMACNA HVAC-DCS. Those classifications pertain to maximum
operating pressure in the duct as follows: 0.5″ wg maximum.
0.6″ to 2″ wg maximum
1.1″ to 2″ wg maximum
2.1″ to 3″ wg maximum
3.1″ to 4″ wg maximum
4.1″ to 6″ wg maximum
6.1″ to 10″ wg maximum
Page 43 of 79
© Retrotec 2017
B.2
Leakage Class Lookup
If you know the Leakage Factor and the Pressure Class, use the following table to determine Leakage
Class. You may also use Retrotec FanTestic Software or a calculation spreadsheet.
Select the pressure value shown under the flow rate on the X axis (in this example, 2 in WC). Then select
the closest Leakage Factor (in CFM/100 sq ft) as was observed on the DM32. Where they coincide, is the
Leakage Class.
Eg. @ Pressure is 2 in WC and Leakage Factor is 8 then the Leakage Class is 5.1.
@ Pressure, in WC >>>
Leakage Factor,F
CFM/100 sq ft
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
12
14
16
18
20
22
24
26
28
30
35
40
45
50
55
60
65
70
75
85
95
105
0.2
Leakage Class, CL
0.5
1
2
1.7
2.3
2.8
3.4
4.0
4.6
5.1
5.7
7.1
8.5
10.0
11.4
12.8
14.2
15.7
17.1
18.5
19.9
21.3
0.9
1.3
1.6
1.9
2.2
2.5
2.8
3.1
3.9
4.7
5.5
6.3
7.1
7.8
8.6
9.4
10.2
11.0
11.8
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
22.8
24.2
25.6
27.0
28.5
34.2
39.9
45.5
12.6
13.3
14.1
14.9
15.7
18.8
22.0
25.1
28.2
31.4
34.5
37.7
40.8
43.9
47.1
8.0
8.5
9.0
9.5
10.0
12.0
14.0
16.0
18.0
20.0
22.0
24.0
26.0
28.0
30.0
35.0
40.0
45.0
Figure 19 Leakage Class lookup table.
Page 44 of 79
© Retrotec 2017
0.4
0.5
0.6
0.8
0.9
1.0
1.1
1.3
1.6
1.9
2.2
2.5
2.9
3.2
3.5
3.8
4.1
4.5
4.8
5.1
5.4
5.7
6.1
6.4
7.6
8.9
10.2
11.5
12.7
14.0
15.3
16.6
17.8
19.1
22.3
25.5
28.7
31.9
35.1
38.2
41.4
44.6
47.8
3
4
6
8
10
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.2
1.5
1.7
2.0
2.2
2.4
2.7
2.9
3.2
3.4
3.7
0.2
0.3
0.4
0.5
0.6
0.6
0.7
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
0.2
0.2
0.3
0.4
0.4
0.5
0.6
0.6
0.8
0.9
1.1
1.2
1.4
1.6
1.7
1.9
2.0
2.2
2.3
0.2
0.2
0.3
0.3
0.4
0.4
0.5
0.5
0.6
0.8
0.9
1.0
1.2
1.3
1.4
1.6
1.7
1.8
1.9
0.1
0.2
0.2
0.3
0.3
0.4
0.4
0.4
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.5
1.6
1.7
3.9
4.2
4.4
4.7
4.9
5.9
6.9
7.8
8.8
9.8
10.8
11.8
12.7
13.7
14.7
17.1
19.6
22.0
24.5
26.9
29.4
31.8
34.3
36.7
41.6
46.5
3.2
3.5
3.7
3.9
4.1
4.9
5.7
6.5
7.3
8.1
8.9
9.7
10.6
11.4
12.2
14.2
16.2
18.3
20.3
22.3
24.4
26.4
28.4
30.5
34.5
38.6
42.6
2.5
2.7
2.8
3.0
3.1
3.7
4.4
5.0
5.6
6.2
6.9
7.5
8.1
8.7
9.4
10.9
12.5
14.0
15.6
17.2
18.7
20.3
21.8
23.4
26.5
29.6
32.8
2.1
2.2
2.3
2.5
2.6
3.1
3.6
4.1
4.7
5.2
5.7
6.2
6.7
7.2
7.8
9.1
10.4
11.6
12.9
14.2
15.5
16.8
18.1
19.4
22.0
24.6
27.2
1.8
1.9
2.0
2.1
2.2
2.7
3.1
3.6
4.0
4.5
4.9
5.4
5.8
6.3
6.7
7.8
9.0
10.1
11.2
12.3
13.4
14.6
15.7
16.8
19.0
21.3
23.5
B.3
Leakage Factor
Leakage Factor, F, is the maximum allowable leakage in CFM per 100 square feet of ductwork (not
counting blanking plates used to seal the ducts). This can be obtained from the graph, the table or the
formula.
B.3.1.
Leakage Factor from the graph
For example, if the Test Pressure was 2 in WC and the Leakage Class was 12 then the Leakage Factor, F
would be 18.8 CFM per 100 square feet.
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B.3.2.
Leakage Factor from the formula
F= CL x P 0.65
Where:
CL is the Leakage Class
P is the Test Pressure in in WC
0.65 is the exponent.
Example:
CL =12
P =2.0 in WC
0.65 is the exponent.
F=12 x 2.0 0.65 =18.83 CFM per 100 square feet.
Page 46 of 79
© Retrotec 2017
B.3.3.
Test
Pressure,
in WC
Leakage Factor from a table
Leakage Factor, F in CFM/100 square feet
Class 3 Class 6 Class 12
Class 24
Class 48
0.05
0.4
0.9
1.7
3.4
6.7
0.10
0.7
1.3
2.7
5.4
10.7
0.20
1.1
2.1
4.2
8.4
16.8
0.30
1.4
2.7
5.5
11.0
21.9
0.40
1.7
3.3
6.6
13.2
26.4
0.50
1.9
3.8
7.6
15.3
30.6
0.60
2.2
4.3
8.6
17.2
34.4
0.70
2.4
4.8
9.5
19.0
38.1
0.80
2.6
5.2
10.4
20.8
41.5
0.90
2.8
5.6
11.2
22.4
44.8
3
6
12
24
48
1.5
3.9
7.8
15.6
31.2
62.4
2.0
4.7
9.4
18.8
37.7
75.4
2.5
5.4
10.9
21.7
43.4
86.8
3.0
6.1
12.2
24.5
49.0
98.0
3.5
6.7
13.6
27.1
54.2
108.5
4.0
7.4
14.8
29.5
59.0
118.1
4.5
8.0
16.0
5.0
8.6
17.1
5.5
9.1
18.2
6.0
9.6
19.2
7.0
10.6
21.2
8.0
11.6
23.2
9.0
12.5
25.0
10.0
13.4
26.8
11.0
14.3
28.5
1
Table 7 Leakage Factor
Page 47 of 79
© Retrotec 2017
B.4
Pressure Class
B.4.1.
Duct pressure classifications
The duct system designer should designate the Pressure Class or classes for construction of each duct
system and clearly identify these in the contract document.
Where no pressure classes are specified by the designer, the 1 inch Water Column (in WC) Pressure
Class will be the basis of compliance with SMACNA, regardless of velocity in the duct, except variable
volume duct upstream of VAV boxes which must have a 2″ in WC Pressure Class.
Conventional leak testing requires a positive test pressure.
B.4.2.
Specified Test Pressure
The ducts should be tested at this pressure if specified but the Test Pressure shall not exceed the
Pressure Class. Normally the designer will specify the Test Pressure.
Page 48 of 79
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Appendix C U.S. Duct Leakage - Measurement Procedure 1
(CFM/100 sq ft)
Picture of DM32 display showing Leakage Factor of 10.54
CFM/100 sq ft @ 4.0000 in WC on Channel B.
Notice the duct surface area of 1255 square feet is
displayed in lower left of the screen. The actual test
pressure is 3.2157 in WC but the gauge displays in units of
flow at the specified Test Pressure of 4.000 in WC using the
extrapolation feature identified because “@” pressure “is
On” in top left corner.
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C.1
How much duct surface area can be tested at one time?
The table below shows the maximum surface area that one Model 400 blower will test if the ducts just
pass. Since ducts will usually be tighter than the minimum specified, much larger areas can normally be
tested than those shown on the table.
Test Pressure,
in WC
20
10
6
4
3
2
1
0.5
0.1
Duct Leakage Class ( CL ), CFM/100 square feet of leakage that would
occur at pressures in inches WC shown on top row
1
2
4
8
16
32
48
4,066
2,033
1,017
508
254
127
85
6,380
3,190
1,595
798
399
199
133
8,893
4,446
2,223
1,112
556
278
185
11,575
5,787
2,894
1,447
723
362
241
13,955
6,977
3,489
1,744
872
436
291
18,162
9,081
4,541
2,270
1,135
568
378
28,500
14,250
7,125
3,563
1,781
891
594
44,721
22,361
11,180
5,590
2,795
1,398
932
127,305
63,652
31,826
15,913
7,957
3,978
2,652
Duct Surface Area, square feet
Table 8 Duct Surface area that can be tested with one Model 400
The extrapolation feature in the gauge allows accurate readings to be taken at 0.1 in WC, so the bottom
row may be used to determine the surface area of duct that can be tested at one time. Duct systems
with larger areas will have to be broken down into sections using barriers and the results added up..
If you cannot achieve 0.1 in WC for the surface areas listed, the ducts will fail the test and must be
sealed up more before additional testing is attempted. Also look for disconnect and sections that are
not correctly blanked off. Check all temporary plugs, plates, sheets, balloons, bags used to seal
intentional openings.
Page 50 of 79
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C.2
Checklist
Test Technician _________________________________________________________ Test Date _____________
Test Location
_________________________________________________________
Follow the color Model 441/451 Quick Guide that comes with your system. Print out these four pages
to direct your test. Use this Test Form if Leakage Factor is the pass/fail criteria for the test. If not, use
“Appendix X2 U.S. CFM at Test Pressure or % leakage”.
□
Check off each box to learn the procedure for your first test.
Pass Fail for U.S. tests
Leakage Factor in CFM/100 sq ft at a specified Test Pressure is often the pass/fail criteria. Leakage
Factor is measured and read out directly on the DM32 Gauge.
This is common wording for the pass/fail criteria:
1. “If, at the specified test pressure, the Leakage Factor (F), by test, is lower than or equal to that
associated with the specified Leakage Class, the duct is in compliance. “
2. “If the Leakage Class (CL) determined from tests is lower than or equal to the specified leakage
class, the duct is in compliance.”
Follow Steps 1 to 7.
If you fail and the specifying Engineer wants a higher Test Pressure, measure the Leakage Class to convince the
Engineer that you have sufficient test flow but the ducts are too leaky to pass regardless of Test Pressure.
Notes:
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
Page 51 of 79
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C.2.2.
Step 1 - Prepare the gauge - first time only
Once the Gauge has been set up, all settings are restored when the gauge is turned back on.
□
Home screen must
show Model 450 on
Range 47
□
Home screen must show pressure
units of CFM at a pressure in WC
per 100 square feet.
If not, tap picture, then [Change Device].
Tap ... until “Retrotec DucTester” page appears.
Tap “450”.
Tap the number below to get Range 47
If not, tap [Settings] and [Results to be displayed].
Tap pressure units until you see inches of Water Column:
Then tap flow units until you see:
Tap On button to return Home.
Once set, you’ll never have to change it again.
If not, tap [Settings] and [Time Averaging] until “ 5 s avg”
is displayed. Tap On button to return Home.
This will create a running average that will smooth out
results, making them easier to read. If the result
fluctuates, increase up to 30 seconds. Refer to manual for
more information.
The Gauge is set up now and you’re ready for your first test.
□
Home screen must time average
as 5 seconds.
□
C.2.3.
Step 2 – Determine test criteria and prepare the ducts
Determine the specified Leakage Class from design Engineer or
Determine the Leakage
determine using SMACNA Table 4-1.
Class
□
Determine the Pressure
Class
□
Measure duct area
□
Ensure sealing is complete
□
Blank off ductwork
Page 52 of 79
© Retrotec 2017
See section on Leakage Class.
Use specified value. If not specified, use a Pressure Class of 1 in
WC except upstream of VAV boxes, use 2 in WC. Use a positive
test pressure unless specified otherwise. Test pressure shall not
exceed the Pressure Class according to SMACNA “HVAC Air Duct
Leakage Test Manual”.
Select a limited section of duct for which the estimated leakage
will not exceed the capacity of the test apparatus. Measure the
duct surface area in square feet. See Table Duct Surface area
that can be tested with one Model 400.
Ensure sealing materials have cured for the prescribed time or at
least 24 hours OR follow manufacturer’s directions.
Blank off and seal the tested ductwork by inserting temporary
plugs plates, sheets, balloons, bags into intentional openings.
□
□
□
□
□
□
□
□
□
C.2.4.
Step 3 – Connect DucTester to ducts
Attach 4 inch Flange to ductwork.
Attach 4 inch collar on flex to
flange
Connect DucTester exhaust to
flex
Range 47 provides 52 to 206 CFM, which is sufficient to
Install Range 47 Flow Plug
test most duct runs.
C.2.5.
Step 4 –Tubing, control and power connections
Connect yellow and green tubes between
DucTester fan and gauge
Connect blue tube between gauge and ducts
using static probe or connection on flange
Plug in the Speed Control Cable between
DucTester fan and Gauge
Plug fan in to power source, turn fan power
on.
C.2.6.
Step 5 – Set up Test Pressure and Area in Gauge
Default @ Pressure in gauge must
match the specified Test Pressure
If not, tap [Settings]
□
and
tap
Then [Set] value to specified Test Pressure.
Since you must not exceed the test pressure,
the actual pressure will be lower but entering
this default will ensure that all results are
displayed at the exact pressure entered.
□
[Area] then use the number pad and
tap [Set].
Page 53 of 79
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Measure the duct surface area in square feet
and enter it into the DM32. Select a limited
section of duct for which the estimated
leakage will not exceed the capacity of the test
apparatus. Area can also be accessed from
[Settings] menu.
C.2.7.
Step 6 – Measure Leakage Factor in CFM/100 sq ft
□
[Set Speed] to 1% then
Jog up to the Test
Pressure.
□
Tap “@” on the display
and “CFM/100 sq ft @
1.0000” will appear
Leakage Factor is
displayed
□
□
WARNING: To prevent over-pressurizing, slowly increase fan speed
using Set Speed. Jog the speed up 1% at a time until a CFM value
appears on the display. Continue to increase fan speed up to but do
not exceed the Pressure Class. If you do not reach the Pressure
Class, results will still be calculated at that Pressure Class.
Measure the Leakage Factor, F by tapping “@” on the display and
CFM/100 square foot @ the Pressure Class will appear. In our
example we set the Default pressure to 1 in WC.
The Leakage Factor, F is displayed as:
Passes if value is lower
than that specified
If this Leakage Factor is lower than or equal to the value specified,
the duct is in compliance. If it fails, measure Leakage Class per
section below.
C.2.8.
Step 7 – Test Passes
Complete test reports
Remove temporary seals.
C.3
Complete test reports and, if required, obtain witness’s signature.
Remove temporary blanks and seals.
If ducts fail, measure the Leakage Class
This is an option if you fail the test or the specification calls for this result.
Look up the Leakage Class
If it fails, additional sealing is
needed.
Page 54 of 79
© Retrotec 2017
If this Leakage Class calculated is lower than or equal to the value
specified, the duct is in compliance. See Figure 20 Leakage Class
lookup table.
Appendix D U.S. Duct Leakage - Measurement Procedure 2
(CFM at Test Pressure or % Leakage)
Picture of DM32 display showing Leakage of 114.8 CFM @
4.0000 in WC on Channel B.
Notice that NO square footage is displayed in lower left of
screen
Page 55 of 79
© Retrotec 2017
When CFM is being measured at the specified Test Pressure, a sheet is often used where there
are multiple duct runs. Individual measurements are made and added to the spreadsheet.
Sometimes results are measured at different test pressure; they should be added to any data
collection sheet the tester has been supplied with. Flows should be totaled.
D.1
How much duct surface area can be tested at one time?
The table below shows the maximum surface area that one Model 400 Blower will test if the ducts just
pass. Since ducts will usually be tighter than the minimum specified, much larger areas can normally be
tested than those shown on the table.
Duct Leakage Class ( CL ), CFM/100 square feet of leakage that would
occur at pressures in inches WC shown on top row
Test Pressure,
in WC
1
2
4
8
16
32
48
4,066
2,033
1,017
508
254
127
85
20
6,380
3,190
1,595
798
399
199
133
10
8,893
4,446
2,223
1,112
556
278
185
6
11,575
5,787
2,894
1,447
723
362
241
4
13,955
6,977
3,489
1,744
872
436
291
3
18,162
9,081
4,541
2,270
1,135
568
378
2
28,500
14,250
7,125
3,563
1,781
891
594
1
44,721
22,361
11,180
5,590
2,795
1,398
932
0.5
127,305
63,652
31,826 15,913
7,957
3,978
2,652
0.1
Duct Surface Area, square feet
Page 56 of 79
© Retrotec 2017
Table 9 Duct Area that can be tested
The extrapolation feature in the gauge allows accurate readings to be taken at 0.1 in WC, so the bottom
row may be used to determine the surface area of duct that can be tested at one time. Duct systems
with larger areas will have to be broken down into sections using barriers and the results added up.
If you cannot achieve 0.1 in WC for the surface areas listed, the ducts will fail the test and must be
sealed up more before additional testing is attempted. Also look for disconnect and sections that are not
correctly blanked off. Check all temporary plugs, plates, sheets, balloons, bags used to seal intentional
openings.
D.2
What Air Handler Flow Rate can be tested at one time?
The table below shows the maximum air handler flow rate that one Model 400 blower will test if the
ducts just pass. Since ducts will usually be tighter than the minimum specified, much flow rates can
normally be accommodated by the Model 400 than those shown on the table.
Test Pressure,
in WC
20
10
6
4
3
2
1
0.5
0.1
1
4,066
6,380
8,893
11,575
13,955
18,162
28,500
44,721
127,305
2
2,033
3,190
4,446
5,787
6,977
9,081
14,250
22,361
63,652
6
678
1,063
1,482
1,929
2,326
3,027
4,750
7,454
21,217
Air Handler Flow Rate, CFM
Table 10 Airhandler Flow rate that can be tested
Page 57 of 79
© Retrotec 2017
Allowable Loss Rate, %
3
4
5
1,355
1,017
813
2,127
1,595
1,276
2,964
2,223
1,779
3,858
2,894
2,315
4,652
3,489
2,791
6,054
4,541
3,632
9,500
7,125
5,700
14,907 11,180
8,944
42,435 31,826 25,461
8
508
798
1,112
1,447
1,744
2,270
3,563
5,590
15,913
D.3
Checklist
Test Technician ___________________________________Test Date _____________
Test Location
_________________________________________________________
Follow the color Model 441/451 Quick Guide that comes with your system. Print out these
four pages to direct your test. Use this Test Form if total CFM at a Test Pressure or Percent
Leakage of the air handler is the pass/fail criteria for the test. If not, use “Appendix B U.S.
Measurement Procedure for Leakage Factor or Leakage Class”.
□ Check off each box to learn the procedure for your first test.
Pass Fail for U.S. tests
Total Duct Leakage at the specified test pressure is the pass/fail criteria and is a value given by
the system designer. CFM flow at the test pressure are read out directly on the DM32 Gauge or
from Retrotec’s FanTestic software.
This is common wording for the pass/fail criteria:
3. “If, at the specified test pressure(s), the Leakage is lower than or equal to the total
specified CFM, the system Passes. “
4. “If, at the specified test pressure, the Leakage is lower than or equal to the specified
percentage of airhandler flow, the system Passes. “
Follow Steps 1 to 7.
Notes:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
________________________________________________________
Page 58 of 79
© Retrotec 2017
D.3.1.
Step 1 - Prepare the gauge - first time only
Once the Gauge has been set up, all settings are restored when the gauge is turned back on.
□ Home screen must
show Model 450 on
Range 47
If not, tap picture, then [Change Device].
Tap ... until “Retrotec DucTester” page appears.
Tap “450”.
Tap the icon with 47 below it to get Range 47
□ Home screen must show
pressure units of in WC and
flow result of CFM
If not, tap [Settings] and [Results to be displayed].
Tap pressure units until you see inches of Water
Column:
Then tap flow units until you see:
Tap On button to return Home.
Once set, you’ll never have to change it for this type
of test.
□ Home screen must time
average as 5 seconds.
If not, tap [Settings] and [Time Averaging] until “ 5 s
avg” is displayed. Tap On button to return Home.
This will create a running average that will smooth
out results, making them easier to read. If the result
fluctuates, increase up to 30 seconds. Refer to
manual for more information.
The Gauge is set up now and you’re ready for your first test.
Page 59 of 79
© Retrotec 2017
D.3.2.
Step 2 – Prepare the ducts
□ Determine the Pressure Class Use specified value. If not specified, use a Pressure
□ Measure duct area
□ – But not if using %
airhandler flow as pass/fail
criteria.
□ Ensure sealing is complete
□ Blank off ductwork
□
□
□
□
□
□
□
□
Class of 1 in WC except upstream of VAV boxes, use 2
in WC. Use a positive test pressure unless specified
otherwise. Test pressure shall not exceed the
Pressure Class according to SMACNA “HVAC Air Duct
Leakage Test Manual”.
Select a limited section of duct for which the
estimated leakage will not exceed the capacity of the
test apparatus. Measure the duct surface area in
square feet.
Ensure sealing materials have cured for the prescribed
time or at least 24 hours OR follow manufacturer’s
directions.
Blank off and seal the tested ductwork by inserting
temporary plugs plates, sheets, balloons, bags into
intentional openings.
D.3.3.
Step 3 – Connect DucTester to ducts
Attach 4 inch Flange to
ductwork.
Attach 4 inch collar on flex to
flange
Connect DucTester exhaust
to flex
Range 47 provides 52 to 206 CFM, which is sufficient
Install Range 47 Flow Plug
to test most duct runs.
D.3.4.
Step 4 –DucTester tubing, control and power connections
Connect yellow and green
tubes between DucTester
and gauge
Connect blue tube to gauge
and to ducts using static
probe or connection on
flange
Plug in the Speed Control
Cable between DucTester
and Gauge
Plug fan in to power source,
and turn power on to fan
Page 60 of 79
© Retrotec 2017
D.3.5.
Step 5 – Set up Test Pressure in Gauge
□ Default in gauge must match the
specified Test Pressure
If not, tap [Settings]
and
,
tap
then [Set] value to specified Test Pressure.
Since you must not exceed the test pressure,
the actual pressure will be lower but entering
this default will ensure that all results are
displayed at the exact pressure entered.
D.3.6.
Step 6 – Run test
□ [Set Speed] to 1%
WARNING: To prevent over-pressurizing, slowly increase fan
speed using Set Speed. Jog the speed up 1% at a time until a
then Jog up to the
CFM value appears on the display. Continue to increase fan
Test Pressure.
□ Tap “@” on the
display and “CFM @
Test Pressure” will
appear.
□ CFM at specified test
pressure is displayed
□ Passes if value is
lower than that
specified
speed up to but do not exceed the Pressure Class. If you do
not reach the Pressure Class, results will still be calculated at
for that Pressure Class.
Measure the CFM at the exact test pressure by tapping “@”
on the display and CFM @ the Pressure Class will appear. In
our example we set the Default pressure to 1 in WC.
The Flow is
displayed as:
In this example the
flow is 92.91 CFM
at 1.0000 inches of
Water Column.
If the total leakage
is lower than or
equal to the value
specified, the duct is in compliance. If it fails.
D.3.7.
Step 7 – Test Passes
□ Complete test reports Complete test reports and obtain witness’s signature.
□ Remove temporary
seals.
Page 61 of 79
© Retrotec 2017
Remove temporary blanks and seals.
Appendix E
UK Duct Leakage Calculation (DW/143)
Engineer specifies the required Airtightness Class for the Ducts.
E.1
Ductwork Classification and Air Leakage Limits
UK Ductwork Classification
Airtightness Class
A
B
C
Positive static pressure limit (ps), Pa
500
1 000
2 000
Negative static pressure limit (ps), Pa
500
750
750
Air Leakage limit (f max), L/(s * m2)
0.027* pt 0,65 0.009*pt 0,65 0.003*pt 0,65
Where pt = test pressure, Pa
Table 11 UK Airtightness Class and Leakage limits
E.2
Test Sheet
Test details
Date
Tester
Witness
Project
Building location
Elevation, m
Temperature, °C
Duct Parameters
Ductwork section tested
Ductwork Classification
Static Pressure (from designers), Pa
Surface Area of ductwork tested, m2
Equipment Specifications
Test fan manufacturer
Test fan model series
Test gauge model
Test fan flow capacity
Test data
Duct pressure induced, Pa
Air Leakage result, L/(s * m2)
Air Leakage Limit at test pressure, f max , L/(s * m2)
Pass/Fail?
Duration of Test, min
Page 62 of 79
© Retrotec 2017
[YYYY-MM-DD], [Time]
[Technician Name], [Company]
[Official’s Name]
[Building Name]
[Address]
[City], [State], [Country], [Zip code]
[Supply system], [Floor]
[A/B/C]
Retrotec
400
DM32
144 L/s (at 250 Pa duct pressure)
[from gauge’s Channel A pressure]
[from gauge’s Channel B Flow/Area result]
[from Table 11]
[“Pass”/”Fail”]
[15 minutes or greater]
E.3
UK Measurement Procedure (Summary)
Connect DucTester fan to ductwork.
Set Duct Pressure [“Adjust test rig until static pressure differential is obtained”].
Verify results are within Air Leakage Limit.
Maintain test for 15 minutes and verify air leakage rate has not increased.
Stop the fan, immediately Set Pressure again, and verify air leakage rate is not greater than previous
reading.
Record test data into Test Sheet or enter test data into FanTestic software.
Page 63 of 79
© Retrotec 2017
E.4
UK Measurement Procedure (Detailed)
Test Technician _________________________________________________________ Test Date _____________
Test Location
_________________________________________________________
Follow the color Model 441/451 Quick Guide that comes with your system. Print out these four pages
to direct your test.
□
Check off each box to learn the procedure for your first test.
Pass Fail for UK tests
Air Leakage in L/(s * m2) at a specified Test Pressure is often the pass/fail criteria. Air Leakage is
measured and read out directly on the DM32 Gauge.
This is common wording for the pass/fail criteria:
“If, at the specified test pressure, the Air Leakage of test is lower than or equal to that associated
with the specified Air Leakage Limit (f max) from Table 11, the duct is in compliance. “
Follow Steps 1 to 7.
Notes:
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
Page 64 of 79
© Retrotec 2017
E.4.1.
UK Step 1 - Prepare the gauge - first time only
Once the Gauge has been set up, all settings are restored when the gauge is turned back on.
If not, tap picture, then [Change Device].
□ Home screen must
Tap ... until “Retrotec DucTester” page appears.
show Model 450 on
Tap “450”.
Range 47
□
Home screen must show pressure
units of Pa and Channel B result of L/(s
* m2)) @ a pressure in Pa.
Tap the icon with 47 below to get Range 47
If not, tap [Settings] and [Results to be displayed].
Tap pressure units until you see Pa:
Then tap flow units until you see:
Tap On button to return Home.
Once set, you’ll never have to change it again.
□
If not, tap [Settings] and [Time Averaging] until “ 5 s
avg” is displayed. Tap On button to return Home.
This will create a running average that will smooth
out results, making them easier to read. If the result
fluctuates, increase up to 30 seconds. Refer to
manual for more information.
The Gauge is set up now and you’re ready for your first test.
Home screen must time average as 5
seconds.
E.4.2.
Step 2 – Determine test criteria and prepare the ducts
□
Determine the Pressure to
use
Measure duct area
□
Ensure sealing is complete
□
Blank off ductwork
□
Page 65 of 79
© Retrotec 2017
Use 80 Pa, 160 Pa or 250 Pa depending on the type of building
being tested (Residential, Multi-Family, or Commercial)
Select a limited section of duct for which the estimated leakage will
not exceed the capacity of the test apparatus. Measure the duct
surface area in square meters. See
Table 13 Duct Surface area that can be tested with one Model
400 (metric).
Ensure sealing materials have cured for the prescribed time or at
least 24 hours OR follow manufacturer’s directions.
Blank off and seal the tested ductwork by inserting temporary
plugs plates, sheets, balloons, bags into intentional openings.
□
□
□
□
□
□
□
□
□
E.4.3.
UK Step 3 – Connect DucTester to ducts
Attach 100 mm Flange to
ductwork.
Attach 100 mm collar on flex to
flange
Connect DucTester exhaust to
flex
Install Range 47 Flow Plug
Range 47 provides 52 to 206 CFM, which is sufficient to
test most duct runs.
E.4.4.
UK Step 4 –Tubing, control and power connections
E.4.5.
UK Step 5 – Set up Test Pressure and Area in Gauge
Connect yellow and green tubes between
DucTester and gauge
Connect blue tube to gauge and to ducts
using static probe or connection on flange
Plug in the Speed Control Cable between
DucTester and Gauge
Plug fan in to power source, and turn on
power.
Default in gauge must match the
specified Test Pressure (250 Pa for
Commercial buildings)
If not, tap [Settings]
and
tap
□
Then [Set] value to specified Test Pressure.
Since you must not exceed the test pressure,
the actual pressure will be lower but entering
this default will ensure that all results are
displayed at the exact pressure entered.
□
[Area] then use the number pad and
tap [Set]
Page 66 of 79
© Retrotec 2017
Measure the duct surface area in square feet
and enter it into the DM32. Select a limited
section of duct for which the estimated
leakage will not exceed the capacity of the test
apparatus. Area can also be accessed from
[Settings] menu.
E.4.6.
UK Step 6 – Measure Air Leakage rate in m3/h.m2
□
[Set Speed] to 1% then
Jog up to the Test
Pressure.
□
Tap “@” on the display
and “m3/(h.m2) @ 250
Pa” will appear
Leakage Factor is
displayed
□
□
WARNING: To prevent over-pressurizing, slowly increase fan speed
using Set Speed. Jog the speed up 1% at a time until a flow rate
value appears on the display. Continue to increase fan speed up to
but do not exceed the Test Pressure. If you do not reach the
Pressure, results will still be calculated at that Pressure
Measure the Leakage rate, f by tapping “@” on the display and
m3/(h.m2) @ the Default @ Pressure will appear. In our example
we set the Default @ pressure to 250 Pa.
The Leakage rate, f is displayed as:
Passes if value is lower
than that specified
If this Leakage rate is lower than or equal to the Air Leakage Limit
specified, the duct is in compliance.
E.4.7.
Step 7 – Test Passes
Complete test reports
Remove temporary seals.
Page 67 of 79
© Retrotec 2017
Complete test reports and, if required, obtain witness’s signature.
Remove temporary blanks and seals.
Appendix F
European Duct Leakage Calculation (EN12237)
The Engineer specifies the required Airtightness Class for the Ducts.
F.1
Ductwork Classification
After the test, the Ducts can be given a classification based on the result by looking it up in
Table 12 European Airtightness Class and Leakage limit.
European Ductwork Classification
Airtightness Class
A
B
C
D
Positive static pressure limit (ps), Pa
500
1 000
2 000
2 000
Negative static pressure limit (ps), Pa
500
750
750
750
Air Leakage limit (f max), m3/(s * m2)
0.027 *
pt 0,65/1 000
0.009 *
pt 0,65/1 000
0.003 *
pt 0,65/1 000
0.001 *
pt 0,65/1 000
Table 12 European Airtightness Class and Leakage limits
F.2
Air Leakage Limits
Air Leakage Limit, fmax, is the maximum allowable leakage in m3/(s * m2) of ductwork for that ductwork
to be in that Class.
For example, if the Test Pressure was 500 Pa, fmax would be 0.00153. If the measured f was 0.00143
then the Airtightness Class would have been measured to be A and would Pass if A was the required
Airtightness Class.
The ducts would pass or fail depending on what the required Airtightness Class for the Duct was
specified to be.
Page 68 of 79
© Retrotec 2017
F.3
EU Measurement Procedure
Picture of DM32 display showing Leakage rate of 12.10
CFM/100 sq ft @ 4.0000 in WC on Channel B.
Notice the duct surface area of 690 square feet is displayed in
lower left of the screen. The actual test pressure is 3.235 in
WC but the gauge displays in flow at the specified Test
Pressure of 4.000 in WC.
Page 69 of 79
© Retrotec 2017
F.4
EU How much duct surface area can be tested at one time?
The table below shows the maximum surface area that one Model 400 blower will test if the ducts just
pass. Since ducts will usually be tighter than the minimum specified, much larger areas can normally be
tested than those shown on the table.
Test Pressure, Pa
80
160
250
A
Air Tightness Class
B
C
4.066
2.033
1.017
6.380
3.190
1.595
8.893
4.446
2.223
Duct Surface Area, m2
Table 13 Duct Surface area that can be tested with one Model 400
The extrapolation feature in the gauge allows accurate readings to be taken at 0.1 in WC, so the bottom
row may be used to determine the surface area of duct that can be tested at one time. Duct systems
with larger areas will have to be broken down into sections using barriers and the results added up.
If you cannot achieve 25 Pa for the surface areas listed, the ducts will fail the test and must be sealed up
more before additional testing is attempted. Also look for disconnect and sections that are not correctly
blanked off. Check all temporary plugs, plates, sheets, balloons, bags used to seal intentional openings.
Page 70 of 79
© Retrotec 2017
F.5
European Measurement Procedure for Airtightness Class
Test Technician _________________________________________________________ Test Date _____________
Test Location
_________________________________________________________
Follow the color Model 441/451 Quick Guide that comes with your system. Print out these four pages
to direct your test.
□
Check off each box to learn the procedure for your first test.
Pass Fail for European tests
Air Leakage Factor, fmax m3/(h * m2) at a specified Test Pressure is often the pass/fail criteria. Air
Leakage, f, is measured and read out directly on the DM32 Gauge.
This is common wording for the pass/fail criteria:
“If, at the specified test pressure, the Air Leakage of test is lower than or equal to that associated
with the specified Maximum Allowable Air Leakage Limit (f max) from Table 113, the duct is in
compliance. “
Follow Steps 1 to 7.
If you fail and the specifying Engineer wants a higher Test Pressure, measure the Leakage Class to convince the
Engineer that you have sufficient test flow but the ducts are too leaky to pass regardless of Test Pressure.
Notes:
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
Page 71 of 79
© Retrotec 2017
F.5.1.
EU Step 1 - Prepare the gauge - first time only
Once the Gauge has been set up, all settings are restored when the gauge is turned back on.
If not, tap picture, then [Change Device].
□ Home screen must
Tap ... until “Retrotec DucTester” page appears.
show Model 450 on
Tap “450”.
Range 47
□
Home screen must show pressure
units of Pa and Channel B result
of m3/(h.m2) @ a pressure Pa.
Tap the icon with 47 below to get Range 47
If not, tap [Settings] and [Results to be displayed].
Tap pressure units until you see Pa:
Then tap flow units until you see:
Tap On button to return Home.
Once set, you’ll never have to change it again.
□
If not, tap [Settings] and [Time Averaging] until “ 5 s avg”
is displayed. Tap On button to return Home.
This will create a running average that will smooth out
results, making them easier to read. If the result
fluctuates, increase up to 30 seconds. Refer to manual for
more information.
The Gauge is set up now and you’re ready for your first test.
Home screen must time average
as 5 seconds.
F.5.2.
EU Step 2 – Determine test criteria and prepare the ducts
□
Determine the Pressure to
use
Measure duct area
□
Ensure sealing is complete
□
Blank off ductwork
□
Page 72 of 79
© Retrotec 2017
Use 80 Pa, 160 Pa or 250 Pa depending on the type of building
being tested (Residential, Multi-Family, or Commercial)
Select a limited section of duct for which the estimated leakage will
not exceed the capacity of the test apparatus. Measure the duct
surface area in square feet. See
Table 13 Duct Surface area that can be tested with one Model
400 (metric).
Ensure sealing materials have cured for the prescribed time or at
least 24 hours OR follow manufacturer’s directions.
Blank off and seal the tested ductwork by inserting temporary
plugs plates, sheets, balloons, bags into intentional openings.
□
□
□
□
□
□
□
□
□
F.5.3.
EU Step 3 – Connect DucTester to ducts
Attach 100 mm Flange to
ductwork.
Attach 100 mm collar on flex to
flange
Connect DucTester exhaust to
flex
Install Range 47 Flow Plug
Range 47 provides 52 to 206 CFM, which is sufficient to
test most duct runs.
F.5.4.
EU Step 4 –Tubing, control and power connections
F.5.5.
EU Step 5 – Set up Test Pressure and Area in Gauge
Connect yellow and green tubes between
DucTester and gauge
Connect blue tube to gauge and to ducts
using static probe or connection on flange
Plug in the Speed Control Cable between
DucTester and Gauge
Plug fan in to power source, and turn on
power.
Default in gauge must match the
specified Test Pressure (250 Pa for
Commercial buildings)
If not, tap [Settings]
and
tap
□
Then [Set] value to specified Test Pressure.
Since you must not exceed the test pressure,
the actual pressure will be lower but entering
this default will ensure that all results are
displayed at the exact pressure entered.
□
[Area] then use the number pad and
tap [Set].
Page 73 of 79
© Retrotec 2017
Measure the duct surface area in square feet
and enter it into the DM32. Select a limited
section of duct for which the estimated
leakage will not exceed the capacity of the test
apparatus. Area can also be accessed from
[Settings] menu.
F.5.6.
EU Step 6 – Measure Air Leakage rate in m3/(h m2)
□
[Set Speed] to 1% then
Jog up to the Test
Pressure.
□
Tap “@” on the display
and “m3/(h.m2) @ 250
Pa” will appear
Leakage Factor is
displayed
□
□
WARNING: To prevent over-pressurizing, slowly increase fan speed
using Set Speed. Jog the speed up 1% at a time until a flow rate
value appears on the display. Continue to increase fan speed up to
but do not exceed the Test Pressure. If you do not reach the
Pressure, results will still be calculated at that Pressure
Measure the Leakage rate, f by tapping “@” on the display and
m3/(h.m2) @ the Default @ Pressure will appear. In our example
we set the Default @ pressure to 250 Pa.
The Leakage rate, f is displayed as:
Passes if value is lower
than that specified
If this Leakage rate is lower than or equal to the Air Leakage Limit
specified, the duct is in compliance.
F.5.7.
EU Step 7 – Test Passes
Complete test reports
Remove temporary seals.
Page 74 of 79
© Retrotec 2017
Complete test reports and, if required, obtain witness’s signature.
Remove temporary blanks and seals.
Appendix G
Calculate Flow using gauge readings
The air flow being produced by the calibrated fan is a value that can be calculated based on the pressure
developed by the air moving across the inlet side of the fan towards the exhaust. Because the fan is
calibrated, there are known values describing the mathematical relationship between the fan pressure,
which is measured across the fan inlet, and the resulting air flow through the fan.
The Fan Pressure needed to calculate the fan flow is the difference between the pressure at the pickup
and the pressure in the vicinity of the inlet side of the fan. The fan pressure pickup is located inside the
fan near the inlet side of the fan. Self-referencing fans such as the 450 have the reference port built in,
and it is placed to measure the ambient pressure in the vicinity of the inlet side of the fan.
It is important to set the Device on the gauge to 450 because that tells the gauge not to adjust the “PrB”
value before calculating flow. Such an adjustment is required in the case of flow toward the operator
when the fan is not self-referenced.
Each fan and range combination has a different flow equation. For each fan and range combination
available, the variables needed to calculate flow are listed in the table below. N and K values depend on
the type of fan and the Range Plate/Ring being used. In the case of Range 74, the Equations differ in for
depressurization as noted by the * below.
Since both the fan pressure pickup and the reference for the fan pressure (yellow and green ports on
the fan connected to the gauge) are on the inlet side of the fan, “PrB”, will always show the correctly
referenced fan pressure and can be used directly as the fan pressure, FP, value in the flow equation.
To determine the fan flow for a particular Fan Pressure, insert the values measured for FP and DP, and
the N and K values from the table into the following equation:
CFM = FP ^N * K
Where: FP is the fan pressure from Channel B displayed as “PrB”
DP is the duct pressure from Channel A displayed as “PrA”
There are two conditions for FP that must be met before the calculated flow can be considered valid.
The absolute value of FP must be greater than the minimum fan pressure, MF, from the table and
greater than a factor calculated from the duct pressure, DP, and K2 from the table:
So before calculating flow ensure that: |FP| > MF And: |FP| ≥ |DP|×K2
Range
74
n
K
K2
MF
0.5045
7.0791
0.15
250
74*
0.5045
6.793
0.15
250
47
0.4873
3.253
0.12
250
29
0.4989
1.094
0.15
250
18
0.4993
0.4308
0.15
250
11
0.5022
0.1681
0.14
250
7
0.5009
0.06650
0.08
250
3
0.5540
0.01380
0.1
250
2
0.530
0.006500
0.12
350
1
0.560
0.002040
0.12
350
for depressurization with Adapter on inlet
where Channel A is negative
These Ranges are optional for Model 400
Table 14 Flow Curve Equations –get latest Published Equations from http://retrotec.com/products/software/DM32 Flow
Calculator
Page 75 of 79
© Retrotec 2017
Appendix H
H.1
Calibration Procedure for Model 450
Pressure Gauge
All Retrotec pressure gauges are calibrated in Retrotec’s ISO 17025
accredited lab. The Model DM32-20 gauge supplied reads pressures from
-5000 Pa to + 5000 Pa and has an accuracy better than 1.0 % of reading,
NOT of full scale which is more common and much less accurate.
The gauge has two channels. Channel A is used to measure duct pressure. Channel B is used to measure flow but
only the negative side of the gauge is used. The gauge takes the Channel B reading and converts it to flow based on
the Model and Range shown on the screen.
In the example on the left, the Device is set to “450” and
Range to “47”. It is very important to ensure these are both
correct. The Range is engraved in the orifice plate which also
has a raised color sticker which is printed with “Range 47” in
the case of this example.
Note: results are in m3/(s m2) which is cubic meters per
second per square meter of duct area. Even though the test
pressure is 12003 Pa, results are calculated at exactly 1000 Pa;
this is what “@ is On” means.
Every system comes with a Calibration Certificate for the
Gauge.
H.2
Flow Measurement
The gauge takes the Channel B reading and converts it to flow in any desired units. “Appendix A Flow Conversion
Tables” show how to convert the Channel B Fan Pressure reading to flow in CFM. “Appendix G Calculate Flow
using gauge readings” show how to use the flow equations to get an exact flow result which is what the gauge
does. Whenever the gauge is taking readings, error traps are employed to ensure the readings are always within
the calibrated range of the Device: when using tables, care must be taken to ensure the minimum Fan Pressure
values are considered. The DM32 Calculator spreadsheet employs these error traps.
The Flow Calibration Equations were generated using an ISO 17025 Accredited Flow Chamber.
Flow measurement calibration consists of several parts.
1. The flow signal from Channel B already has an ISO 174025 calibration certificate with each
system.
2. The Flow Plugs used for each Flow Range have their serial numbers recorded and have their
diameters measured on two planes to ensure consistency.
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3. The Published Flow Equations are designated in the firmware of the gauge and in the FanTestic
Software using Round designation that is made public on Retrotec’s website under:
http://retrotec.com/products/software/Tester Tools/DM32 Flow Calculator.
4. Every system has a Calibration Verification document where the Device is tested to ensure the
Flow Signal is appropriate at one point on one curve. Experience has shown that if one point is
verified that the only remaining issue could be the orifice size which is checked in a previous
step. We then know that the Published Equations apply.
5. Optionally, every Range can be checked a minimum, middle and maximum flows to ensure the
Device is within the calibration limits for a particular standard. This option is especially
important if the user wants to ensure the Device is accurate to within ± 3%. Standard calibration
± 5% is guaranteed to be within these tolerances throughout the range the gauge will display
results in. It is recommended that Devices are checked after a year of severe service or 3 years
of standard service or whenever local standard require calibration.
H.3
Flow Calibration Field Check
Occasionally when an authority questions the calibration of this Device or the tester wishes to ensure his Device is
not malfunctioning, we recommend the Filed Calibration Check. Simply cut a 1x3” hole in a box, depressurize to
900 Pa and flow should read 97 CFM on Range 47. You can measure the hole size using EqLA also. Expect the
result to be within 15%. This method will show whether the Device has some kind of problem that prevents it from
working properly. Normally the Device readings will be within 2 or 3% of the actual value.
H.4
Fan Calibration Data
The graph below shows the calibration data that
was used to calibrate Range 18 for example.
Twenty-two data points were taken to establish
the shape of the Flow Equation that is noted as:
CFM = 0.4308 X Fan Pressure in Pa to the 0.4993
power.
The flows shown were generated using an ISO
17025 Accredited Flow Chamber. The error %
are the difference between the Flow Equation
created in a curve fit and the values measured.
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© Retrotec 2017
Glossary
Term
“ wg”
airtightness
Blower
Construction Class
Depressurization
digital gauge
DM32
DM32 non-WiFi
DM32 WiFi
Duct Class
Flow Plug
Flow Pressure
Flow Range
Housing
HVAC
in WC
Inches of Water Column
Leakage Class, CL
Leakage Classification
Leakage Constant
Leakage Factor, F
Pascal (Pa)
Pressure Class
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© Retrotec 2017
See “in WC”
Definition
Pertains to how free air leakage may be in an enclosure. In actual fact, measurements
can only be made of air leakage rates not air tightness itself, so one could think of
these terms as being opposites. In spite of the confusion, the terms are used
interchangeably. Air tightness is determined by measuring the air flow rate required
to maintain a specific induced test pressure. (e.g. airtightness can be measured and
reported in units of CFM/sq ft of air leakage at a uniform test pressure of 75 Pa)
Used to refer to a centrifugal fan. Only the Retrotec Model 400 is a Blower.
Unless construction class is otherwise specified it means a static pressure
classification in the SMACNA HVAC-DCS. Those classifications pertain to maximum
operating pressure in the duct as follows:
0.5″ wg maximum
0.6″ to 2″ wg maximum
1.1″ to 2″ wg maximum
2.1″ to 3″ wg maximum
3.1″ to 4″ wg maximum
4.1″ to 6″ wg maximum
6.1″ to 10″ wg maximum
The process of creating a negative pressure in the enclosure by blowing air out of it.
Air is drawn in from outside through leakages of the enclosure to replace the air,
showing up as “geysers” when checked with an Air Current Tester.
A gauge with an electronic pressure sensor and digital display that is capable of
reading in tenths of a Pascal.
A general term for Digital Manometer 32 both with and without WiFi chip.
Specific reference to any DM32 that is not WiFi enabled.
Spoken and marketing term for model DM32W (yellow case with WiFi chip).
see Pressure Class
The 4-inch plug that goes into a Model 300 or 400 Fan/Blower that is used to
measure flow.
Use Fan Pressure instead. Flow Pressure was used in a lot of documentation over the
years but Fan Pressure is a bit more direct and easier to understand.
See “Range Configuration” which is abbreviated as Range Config on DM-2 gauge.
The Shell surrounding the fan or blower in Retrotec test Fans.
Heating Ventilating and Air conditioning system.
Inches of Water Column, Water Gauge, “wg and in WC are all equivalent terms. “in WC” is
used throughout this manual for consistency. This is a common unit of pressure used in the
USA although elsewhere, Pascals (Pa) are more common. One in WC = 249 Pa and is the
amount if pressure that will support a column of water for one inch of height.
See “in WC”
CL = F (leakage rate in CFM/ 100 sq ft) divided by the Pressure in in WC to the 0.65
Power. CL = F / P 0.65
Leakage Constant and Leakage Classification are equivalent terms.
Same as Leakage Class
Same as Leakage Class
F is the allowable leakage in CFM/ 100 sq ft = CL * P 0.65
Where P is the test pressure in in WC and CL is the Leakage Class.
The metric unit of pressure. 1 Pascal is equivalent to 0.000145 psi, or 249 Pascals in 1
in WC (the pressure required to push water up 1” in a tube)
Duct pressure classifications are equivalent to Duct Class
Term
Pressurization
psf
Range A
Range Configuration
test fan
test blower
Water Gauge
test pressure (for
commercial ducts in
Europe)
air leakage rate (for
commercial ducts in
Europe)
air leakage limit (for
commercial ducts in
Europe)
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© Retrotec 2017
Definition
The process of inducing a positive pressure in an enclosure by blowing air into it. Air
is pushed out through all the leaks, causing the smoke to move away from the
operator when checked with an Air Current Tester.
Pounds per square foot. I unit is about 47.88 Pa.
Retrotec’s Range Configuration on a Blower Door that consists of Range Ring A
mounted and all the other Range Rings/Plate NOT mounted on the fan. Range A is a
short form of Range Configuration A.
The configuration of the calibrated fan refers to whether the front of the fan is open
of if it has a Range Plate or Range Ring attached which will change the calibration
curves that must be used to calculate flow. Typically, the gauge is set to the Range
Configuration that matches the configuration of the fan being used to measure flow
or the flow is looked up in a table where the flow is read under the appropriate
Range Configuration and opposite the Fan Pressure.
For this document, this term is used to represent a calibrated variable speed fan that
is typically temporarily mounted in an opening in the envelope for the purpose of
providing a test pressure and for measuring the flow rate required to establish that
test pressure. Other commonly used terms are "Blower Door" and "Door Fan".
See “in WC”
Pressure induced by the duct tester that is created between the duct and the surrounding air.
Ptest in the European standard
Leakage flow rate per unit surface area of the duct. f = qv / Aj
Maximum permitted leakage rate for air tightness class, fmax
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