<b>Start-up and operation </b>. DriSteem HUMIDI-TECH DI, HUMIDI-TECH

SPACE DISTRIBUTION UNIT, EXTERNAL ABSORPTION (SDU-E)

Rise, throw and spread (SDU-E)

As steam is discharged from the humidifier, it quickly cools and turns to a visible fog that is lighter than air. As this fog is carried away from the humidifier by the airstream, it tends to rise toward the ceiling. If this fog contacts solid surfaces

(columns, beams, ceiling, pipes, etc.) before it disappears, it could collect and drip as water. The greater the space relative humidity, the more the fog will rise, throw and spread before disappearing.

The distances the fog travels before it disappears are given in Table 10-1.

Table 10-1 lists the recommended minimum vertical

(rise), horizontal (throw) and width (spread) clearances for SDU-E area-type humidifiers at 40%, 50% and 60% RH in the space.

The SDU-E contains a 926 cmh blower

(m 3 /h) and an airflow proving switch field wired to the

HUMIDI-TECH humidifier electrical panel. A wiring diagram of the SDU-E is included with the unit.

On a call for humidity, the humidifier will begin producing steam and the start relay will energize the

SDU blower. Time-delay is controlled by the

VAPOR-LOGIC ®

3 microprocessor.

VM-4

VM-6

VM-8

VM-10

VM-12

VM-16

VM-21

VM-25

VM-30

VM-34

Table 10-1: SDU-E Visible vapor travel

Model

Rise

(m)

0.30

0.30

0.30

0.50

0.50

0.60

0.60

0.60

0.60

0.60

40% RH@ 21°C 50% RH@ 21°C

2.1

2.3

2.5

2.5

2.5

Throw

(m)

1.5

Spread

(m)

0.30

1.5

1.7

1.8

1.8

0.30

0.30

0.50

0.50

0.60

0.60

0.60

0.60

0.60

Rise

(m)

0.50

0.50

0.50

0.60

0.60

0.60

0.60

0.80

0.80

0.80

2.1

3.0

3.2

3.2

3.2

Throw

(m)

Spread

(m)

2.0

0.50

2.0

2.0

2.1

2.1

0.50

0.50

0.60

0.60

0.60

0.60

0.80

0.80

0.80

Rise

(m)

.80

.80

.80

1.0

1.0

1.0

1.0

1.1

1.1

1.1

60% RH@ 21°C

Throw

(m)

2.3

2.3

2.3

2.5

2.5

2.7

3.7

3.8

3.8

3.8

Spread

(m)

0.80

0.80

0.80

1.0

1.0

1.0

1.0

1.1

1.1

1.1

Table 10-1 notes:

Table 10-1 states the vertical (rise), horizontal

(throw) and width (spread) dimensions that can be expected with the HUMIDI-TECH with SDU-E.

Surfaces cooler than ambient temperature, or objects directly in the path of visible vapor discharge, may cause condensation and dripping.

Rise: Maximum height visible vapor rises above the steam outlet grill of the SDU-E.

Throw: Maximum horizontal distance visible vapor travels from the steam outlet of the SDU-E.

Spread: Maximum width visible vapor spreads out from the steam outlet of the SDU-E.

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VM99-C-0400-M-0801.pdf 10 11/19/2009 9:51:54 AM

DISPERSION USING DISPERSION TUBES

Examples of mounting a dispersion tube

Figure 11-1: Mounted horizontally in duct Figure 11-3: Mounted vertically

Vapor hose

OM-228-1 OM-230-1

Vapor hose and dispersion tube should be pitched back to the humidifier with a gradual slope of 15%.

A single dispersion tube cannot be used with

VM-30 or VM-34.

This is not recommended on models VM-10 through VM-34.

IMPORTANT NOTES: When duct is located more than 3 m away from unit, vapor hose is not recommended; DN40 minimum hard pipe should be used instead. VM-30 and VM-34 must use a multiple tube steam dispersion system.

Figure 11-2: Mounted horizontally in duct and lower than HUMIDI-TECH unit

Tee

150 mm min.

OM-229-1

75 to125 mm (150 to 300 mm for

VM-21, VM-25, VM-30 and VM-34)

A water seal must be located in drain line as shown to maintain steam pressure. A single dispersion tube cannot be used with VM-30 or VM-34.

Table 11-1: Vapor hose sizing

Model

VM 2-10

Capacity kg/hr up to 13.5

VM 12-16 up to 26

VM 12-16 over 26

VM 21-25 up to 38.5

Vapor hose

DN

DN40 hose kit without drain

DN40 hose kit with drain

DN50 hose kit without drain

DN50 hose kit with drain

VM 30-35

These models require multiple tube assemblies.

VM99-C-0400-M-0801.pdf 11

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