Humidity

iCOM Control Training and Service Manual

Temperature

Humidity

Humidity

Content Level

Proportional

Set Point

Set Point

Grains per LB.

 

 

Band = 6%

 

75°F

50%

+3%

59.2

75°F

50%

-3%

52.5

The Absolute (Predictive) Humidity Control Flowchart shows what the program is doing and why.

Programmed Values

Temp Set Point

Humidity Set Point

Humidity Proportional Band

Present

Room Temperature

Room Humidity

 

Calculates Band

 

Compares

 

 

 

Moisture

 

 

 

 

 

Content to

 

 

 

Band and

 

 

 

Makes

Calculates Content

 

Decision

 

 

 

 

 

 

 

Humidify

Dehumidify

The program can be analyzed using the Moisture Content Charts supplied in a later chapter of this manual. It is important to remember that the display provides the humidity value in %RH, not moisture content. The moisture content (grains) values are used only in the internal control program calculation. The LCD display will indicate relative humidity percentage for both methods of control. If the absolute method of control is selected, the adjusted humidity reading will be shown.

When utilizing the absolute (predictive) humidity control program feature, the humidity level is automatically adjusted ~ 2% RH for each degree difference between the return air temperature and the temperature set point.

When absolute humidity control is used, over dehumidification is avoided in the space. When overcooling occurs, causing an increase in the relative humidity reading, the humidity control program “predicts” what the RH will be when the dehumidification cycle ends and the temperature returns to the programmed set point. This allows the dehumidification cycle to end at the proper time.

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Liebert TM-10098 service manual iCOM Control Training and Service Manual, Humidity, Proportional, Set Point, Grains per LB