Humidity Control - Vertiv Liebert iCOM Installer/User Manual

NOTE:
Humidity Control Type
Controls humidification/dehumidification operation. Valid values:
• Proportional: percent of humidification/dehumidification determined by the difference between the humidity
sensor reading and the humidity setpoint.
• Dew Point: percent of humidification/dehumidification determined using the measured return temperature and
humidity to calculate the dew point and comparing it to the setpoints.
NOTE: When dew point is selected, the humidity setpoint and proportional band units are degrees dewpoint.
• Relative: Percent of humidification/dehumidification determined using the measured humidity content of the
air to calculate the percent relative humidity (RH) and comparing it to the setpoints.
NOTE: Relative humidity control can cause unnecessary humidification/dehumidification from over cooling based on a
higher than normal RH reading that causes extended dehumidification. This in turn causes a low RH reading that
activates the humidifier.
• Compensated: Percent of humidification/dehumidification determined using the measured humidity content of
the air and automatically adjusting the humidity setpoint.
NOTE: Compensated humidity control prevents unnecessary humidification/dehumidification noted with relative

humidity control.

• Predictive: Percent of humidification/dehumidification determined using the measured humidity content of the
air and automatically adjusting the humidity sensor reading.
Humidity Deadband
Widens the setpoint to prevent small changes in humidity from cycling components and also maximizes component
life. When humidity is within the deadband, no humidification/dehumidification occurs.
Humidity Integration Time
Adjusts unit capacity based on the length of time the humidity has deviated from the setpoint. Works in conjunction
with the proportional band to maintain tight setpoint control.
Humidity Proportional Band
Adjusts the activation point of humidifier/dehumidification components based on deviation from setpoint by placing
half of the selected value on each side of the humidity control setpoint. A smaller number causes faster reaction to
humidity changes.
Humidity Setpoint
Humidity level by adding moisture to or removing moisture from the air.
3.1.8 Humidity Control
Humidity control refers to the cooling unit's response to programmed setpoints and sensed humidity conditions.
iCOM™ controls humidity based on temperature and humidity sensor readings. The requirement is expressed as a
percentage (%) and is calculated using the selected humidity control type.
3 Service Operation
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