Emerson Liebert iCOM Manual De Usuario

Compensated—The actual return air humidity sensor reading is sent to the Temperature and 

Humidity Control where the Humidity Setpoint is adjusted based on how much the return room air 

temperature deviates from the temperature setpoint. The adjusted humidity setpoint is used for 

humidification percent requirement determination. For every 1°C deviation from the temperature 

setpoint, the humidity setpoint is changed by 3% RH, inversely proportionally: if the temperature 

increases, the humidity setpoint is decreased, and vice versa. The recalculated humidity setpoint is 

shown as the Actual Humidity Setpoint (User Menu, Sensor Data). As the humidity setpoint is 

automatically adjusted, the high and low humidity setpoints (User Menu, Set Alarms) are adjusted 

accordingly. The unadjusted humidity sensor reading is displayed on the Status menu.
Predictive—The actual return air humidity sensor reading is adjusted before it is sent to the 

Temperature and Humidity Control. The humidity sensor reading is adjusted based on how much the 

return room air temperature deviates from the desired temperature setpoint. For every 1°C deviation 

from the temperature setpoint, the humidity sensor reading is changed by 3% RH, directly 

proportionally: if the temperature increases, the humidity reading is increased and vice versa. The 

adjusted humidity sensor reading is displayed in the Status menu. Predictive humidity control is set 

at the factory as the default.
If Compensated or Predictive humidity sensor control is selected, overdehumidification is avoided. 

When overcooling occurs, causing an increase in the relative humidity sensor reading, the humidity 

control program predicts what the RH will be when the dehumidification cycle ends and return air 

temperature returns to the setpoint. This allows the dehumidification cycle to end at the proper time. 

The Compensated and Predictive humidity sensor control can reduce energy consumption by 

minimizing compressor and reheat operation, and eliminating unnecessary humidifier operation.

Humidity Control Types
The Liebert iCOM has two Humidity Control Types:

• Proportional
• PI

Proportional—The control uses the humidity proportional band to determine whether to humidify 

or to dehumidify and how much capacity to provide. The Humidity Proportional Band is a 

user-defined range divided into two equal parts for humidifying and dehumidifying. The Humidity 

Setpoint is located between these two equal parts. An optional Humidity Deadband range can be 

defined, which is equally divided on either side of the setpoint and separates the two halves of the 

proportional band. Figure 45 illustrates how the humidity proportional band is evenly divided on 

either side of the humidity setpoint, with and without a deadband.

0%

Setpoint

0%

+ 100% 

Dehumidification

- Hum

+ Hum

0%

Setpoint

½ Proportional Band

- 100% 

Humidification

- 100% 

humidification

Without Deadband

With Deadband

- Hum

+ 100% 

Dehumidification

+ Hum

½ Proportional Band

½ Proportional Band

½ Proportional Band