Whirlpool | LDR3822PQ | Ventilation Specification | Whirlpool LDR3822PQ Ventilation Specification

Table of Contents
DRYER VENTING SPECIFICATIONS..................................................................................................1
DRYER SAFETY....................................................................................................................................1
INSTALLATION REQUIREMENTS ......................................................................................................4
Venting Requirements .......................................................................................................................5
DRYER INSPECTION AND CLEANING ..............................................................................................7
Frequency of Exhaust System Cleaning ...........................................................................................7
Inspecting the Exhaust System .........................................................................................................7
Your safety and the safety of others are very important.
We have provided many important safety messages in this manual and on your appliance. Always read and obey all safety
This is the safety alert symbol.
This symbol alerts you to potential hazards that can kill or hurt you and others.
All safety messages will follow the safety alert symbol and either the word “DANGER” or “WARNING.”
These words mean:
You can be killed or seriously injured if you don't immediately
follow instructions.
You can be killed or seriously injured if you don't follow
All safety messages will tell you what the potential hazard is, tell you how to reduce the chance of injury, and tell you what can
happen if the instructions are not followed.
If you are installing a gas dryer, it is recommended that the owner post, in a prominent location, instructions for the customer’s use in
the event the customer smells gas. This information should be obtained from your local gas supplier.
Post the following warning in a prominent location.
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
WARNING: For your safety, the information in this manual must be followed to minimize
the risk of fire or explosion, or to prevent property damage, personal injury, or death.
– Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this
or any other appliance.
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Clear the room, building, or area of all occupants.
• Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's
• If you cannot reach your gas supplier, call the fire department.
– Installation and service must be performed by a qualified installer, service agency, or
the gas supplier.
In the State of Massachusetts, the following installation instructions apply:
Installations and repairs must be performed by a qualified or licensed contractor, plumber, or gasfitter qualified or licensed by
the State of Massachusetts.
If using a ball valve, it shall be a T-handle type.
A flexible gas connector, when used, must not exceed 3 feet.
WARNING: To reduce the risk of fire, electric shock, or injury to persons when using the dryer, follow basic precautions,
including the following:
Read all instructions before using the dryer.
Do not place items exposed to cooking oils in your dryer.
Items contaminated with cooking oils may contribute to
a chemical reaction that could cause a load to catch fire.
Do not dry articles that have been previously cleaned in,
washed in, soaked in, or spotted with gasoline, drycleaning solvents, or other flammable or explosive
substances as they give off vapors that could ignite or
Do not allow children to play on or in the dryer. Close
supervision of children is necessary when the dryer is
used near children.
Before the dryer is removed from service or discarded,
remove the door to the drying compartment.
Do not reach into the dryer if the drum is moving.
Do not install or store the dryer where it will be exposed
to the weather.
Do not tamper with controls.
Do not repair or replace any part of the dryer or attempt
any servicing unless specifically recommended in this
Use and Care Guide or in published user-repair
instructions that you understand and have the skills to
carry out.
Do not use fabric softeners or products to eliminate static
unless recommended by the manufacturer of the fabric
softener or product.
Do not use heat to dry articles containing foam rubber or
similarly textured rubber-like materials.
Clean lint screen before or after each load.
Keep area around the exhaust opening and adjacent
surrounding areas free from the accumulation of lint, dust,
and dirt.
The interior of the dryer and exhaust vent should be
cleaned periodically by qualified service personnel.
See installation instructions for grounding requirements.
IMPORTANT: The gas installation must conform with local codes, or in the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.1/NFPA 54.
The dryer must be electrically grounded in accordance with local codes, or in the absence of local codes, with the National
Electrical Code, ANSI/NFPA 70.
Local codes and ordinances that exist must also be met. Consult
your local building inspector for more information.
Improper venting can cause moisture and lint to collect
indoors, which may result in:
Moisture damage to woodwork, furniture, paint, wallpaper,
carpets, etc.
Housecleaning problems and health problems.
Fire Hazard
Use a heavy metal vent.
Do not use a plastic vent.
Do not use a metal foil vent.
Failure to follow these instructions can result in death
or fire.
WARNING: To reduce the risk of fire, this dryer MUST BE
NOTE: This guide is intended to aid licensed HVAC or
Architectural Engineers who design single and multi-dryer unit
venting systems for Whirlpool Corporation dryers sold in the
United States. Whirlpool Corporation provides required airflow
and back pressure specifications, measured at the connection
between the vent system and the dryer’s vent pipe, for use in the
design of dryer vent systems. Whirlpool does not design multidryer vent systems, nor does Whirlpool review or provide
approvals for vent systems designed by third-party engineering
A normal towel load contains some residual water when it is
removed from the washer. The dryer must remove this water and
discharge it from the drum. When the dryer is not exhausted
outside, this moist air will be recirculated through the heating
source, reducing the dryer’s efficiency.
Exhausting moisture into the room can also cause damage to
walls, floors, picture hangers, and cause condensation on
windows and walls in cold weather.
Even though the dryer is equipped with a lint screen, fine particles
of lint can get through the screen and be exhausted out of the
dryer. Proper venting of the dryer will keep lint from accumulating
in the laundry area.
In order to remove moisture from the garments in the dryer, heat is
generated to vaporize the water. Exhausting the dryer outdoors
removes excess heat from the laundry area of the building.
Outside Exhaust
The four basic reasons for exhausting a dryer outdoors are
detailed in this section:
1. To meet codes requirements.
2. To remove moisture from laundry area.
3. To avoid lint accumulation in laundry area.
4. To remove excess heat from laundry area.
Codes Requirements
The following codes should be reviewed to ensure dryer vent
systems are in compliance:
1. International Mechanical Code: In the 2000 version, sections
504 and 913.
2. International Fuel Gas Code: In the 2003 version, section 614.
3. UL 2158 Electric Clothes Dryer Standard references venting
requirements in paragraph 7.3.
4. ANSI Z21.5.1 - Gas Clothes Dryers.
5. Other sections of these codes may also apply to multi-dryer
vent systems.
There are other codes requiring dryers to be exhausted when
installed in confined spaces where specified clearances from
combustible surfaces cannot be met. See the Installation
Instructions that came with your dryer for spacing requirements.
Central Exhaust System Requirements
The following guidelines should be considered in the design of
any central exhaust system:
■ Exhaust individual dryers to the central exhaust duct system
with proper size vents to assure adequate performance of
each dryer. The dryer has 4" (102 mm) exhaust duct
connections. Four inch (102 mm) diameter aluminum vent
should be used to connect each dryer to the central vent.
Install weighted dampers on each individual dryer exhaust
duct. These dampers may be used for balancing out the
overall duct system.
Provide for a maximum of 0.1" (2.5 mm) of water column
vacuum in the central exhaust duct and a maximum of
0.6" (15 mm) of water column back pressure at the connection
of each dryer exhaust vent at any time that the dryer is in
operation. See “Venting Requirements” for instructions on
how to measure water column back pressure.
Design the central duct system for sufficient capacity to
handle the maximum number of dryers operated at one time.
Consider moisture, lint and air temperature in the design of the
central duct system. Maximum exhaust temperature of the
dryer will not exceed 200°F (93.3°C) when the dryer is
operated according to the instructions provided with the dryer.
Provide for periodic inspection and clean-out of lint
accumulated in the central duct system.
Venting Requirements
Venting systems for Whirlpool dryers must meet the following
■ The capacity to handle 200 CFM of air for each dryer in the
A back pressure of -1.0" (-25 mm) water column to
0.6" (15 mm) of water column when measured at the
connection to the dryer.
The minimum duct air velocity during normal operating
conditions should be at least 1,100 FPM to keep lint moving
in the air stream. (In a 4” diameter pipe, this requires at
least 96 CFM.)
Back pressure should be measured with an empty dryer, a clean
lint screen and with the dryer operating in the Air Only cycle
(no heat). Use an inclined manometer, such as Dryer model
102 (0"-2" [0 mm - 51 mm] range) or Dryer model 172
(0"-1" [0 mm - 25 mm] range) to measure the back pressure.
See the following illustration.
Dryer Airflow
The airflow of a dryer depends on the design of the exhaust vent.
Each dryer model has a maximum rated vent length, shown in the
product literature that is supplied with each model, or on the
Whirlpool.com website. The exhaust airflow of any Whirlpool
produced dryer at the maximum rated vent length is at least
100 CFM. The maximum airflow is 200 CFM. This includes
standard vent and long vent dryer models.
Codes Agency Approvals
All Whirlpool electric dryer models, including “long vent dryers,”
that are sold in the United States and Canada are UL listed
(reference UL2158 standard), and all Whirlpool gas dryer models
are CSA listed (reference ANSI Z21.5.1 standard). These
standards require testing at the maximum-rated exhaust vent
conditions that are published in the product literature for each
individual model. The designation for the UL or CSA listing can be
found on or adjacent to the serial label on the product.
Dryer Closet Installations
Closets used for dryer installation must provide multiple openings
to allow air to flow through the dryer and around the dryer to
dissipate heat. Refer to the product literature for details of room
venting requirements. Any dryer enclosure or room that does not
have an inlet and outlet for an operating forced air HVAC system is
considered a closet, and requires room venting as stated in the
product literature. The room venting can be installed into the walls
of the dryer enclosure, as well as the door, provided it will not be
blocked after the dryer is installed. Refer to the product literature
for minimum clearances between the product and the enclosure
“AF” Code
A. Dryer - empty and running on Air Only cycle
B. 12" (305 mm) min. of straight pipe - measure
back pressure from the center
C. To vent system
D. 0.6" (15 mm) water maximum back pressure
E. Inclined manometer
Certain electronic dryer models have airflow detection
capabilities. (See specific model product literature for details). If
the airflow in the dryer is extremely low, an “AF” code will be
displayed on the control panel. For single dryer venting systems,
this code means that you may have a blocked or partially blocked
vent or that your overall vent system length is too long. To resolve
this issue:
■ Check to see if the vent run from the dryer to the wall is
crushed. Refer to the “Venting Requirements” section of
the Use and Care Guide for more information.
Confirm that the vent run from the dryer to the wall is free
of lint and debris.
Confirm that the exterior vent exhaust hood is free of lint
and debris.
Confirm that your vent system falls within the
recommended run length and number of elbows for the
type of vent you are using. Refer to the “Plan Vent
System” section of the Use and Care Guide for details.
Select a Timed Dry heated cycle, and restart the dryer.
If the message persists, have your entire home venting run
Single Dryer Venting Systems
Single dryer venting systems are defined as systems that have
only one dryer unit attached to a residential-type 4" (102 mm)
diameter rigid metal vent system. For single dryer venting
systems, see the Installation Instructions that came with your
dryer to determine the allowable length and number of elbows for
the venting system.
Additional Elbows
In cases in which the Installation Instructions do not address the
vent length for the specific number of elbows required for a
particular application, the following calculations may be used.
(The total vent system length includes all straight and curved
portions of the vent system.):
■ For 90° elbows, reduce the allowable vent system length by
10 ft (3.05 m).
For 45° elbows, reduce the allowable vent system length by
6 ft (1.83 m).
For example, if the Installation Instructions state that a dryer is
allowed 40 ft (12.2 m) of total vent length with two 90° bends, and
the installation requires three 90° bends, the total allowable vent
length would be reduced by 10 ft (3.0 m) (from 40 ft [12.2 m] to
30 ft [9.1 m]).
For multi-dryer venting systems, the “AF” code means that your
vent may be blocked or partially blocked or that the venting
system is creating back pressure in excess of the maximum
allowable 0.6" (15 mm) water column. In this case, the engineering
firm that designed the system should be consulted.
Multiple Dryer Venting Systems
Multiple dryer venting systems must be designed specifically for
each application.
NOTE: It is recommended that an architectural or HVAC
engineering firm be consulted for designing the dryer venting
Connecting a number of dryers to a single vent system is
common in coin-laundry stores and in many apartment buildings.
Listed here are some requirements for examples of three different
multiple dryer venting systems.
Option 1 - Horizontal System
The most common is the horizontal system, in which banks of
dryers are all located in one room and vented through a common
duct. See the following illustration for an example of a generic
horizontal system.
Option 3 - Combination System
The combination system may be used in high-rise apartments,
with a bank of dryers installed at several different levels. Each of
these banks then exhausts into a central vertical vent. See the
following illustration for an example of a combination system.
(25 mm)
A. 4" (102 mm) diameter rigid metal back draft damper
*Minimum spacing required between dryers
Option 2 - Vertical System
The vertical system is used in some apartment buildings that have
a washer and dryer on each floor. Each dryer is exhausted into the
same central vertical duct. See the following illustration for an
example of a generic vertical system.
A. 0.6" (15 mm) water column maximum back pressure
B. Weighted dampers
C. Individual dryer exhaust - on each floor
D. 0.1" (2.5 mm) water column maximum vacuum
E. Main duct
F. Barometric damper (use depends on exhaust
system design)
G. Source of outside air
A. Central vertical duct - maximum of
0.1" (2.5 mm) water column vacuum
B. Weighted damper (each dryer)
C. Maximum of 0.6" (15 mm) water column
back pressure
D. Barometric damper (use depends on
exhaust system design)
E. Outside air source
Frequency of Exhaust System Cleaning
Inspecting the Exhaust System
Every exhaust system must be inspected periodically and cleaned
to ensure that it is intact and free from lint accumulation. The
frequency of these inspections will vary, depending on the system
and usage of the dryer. For single-family usage, an annual
inspection is recommended. In commercial usage or in multiple
dryer systems a more frequent inspection is recommended.
Complaints of long drying times or a hot dryer top indicate the
need for inspection of the exhaust system.
1. Disconnect the exhaust duct from the dryer and from the
exhaust hood (at the exhaust outlet).
2. Inspect the interior of the duct and remove any lint
■ Be sure that lint is removed from the exhaust hood. Lint
may collect in the exhaust hood so that the flappers or
louvers (if installed as part of the exhaust system) will not
open or close completely.
After cleaning the exhaust hood, check that the flapper or
louvers move freely.
3. Reassemble the exhaust duct and hood, checking that the
joints are secure.
4. Operate the dryer and verify that the exhaust air is not
obstructed in the vent and that there are no leaks in the
■ Seal any leaks that are found.
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