Data Aire dap4 User Manual page 92

Dehumidification Operation (continued)
Variable Compressor Controlling Relative Humidity
Temp Control set to Return Air: The variable compressor starts at Humidity
Setpoint plus Deadband. The compressor demand will increase 10% for each
0.1% increase in humidity and reach 100% at Humidity Setpoint + Deadband +
1%. C2 (if enabled) will turn on when humidity reaches Humidity Setpoint +
Deadband + 1.1%. As humidity decreases, C2 will turn off when humidity drops to
humidity setpoint + 1% and the the variable compressor demand will begin to
decrease and turn off at Humidity Setpoint minus 1%.
Temp Control set to Discharge Air: The variable compressor starts at Humidity
Setpoint + Deadband. The compressor demand will increase 10% for each .1%
increase in humidity above the Setpoint minus Deadband + 1.1% and reach 100%
at Humidity Setpoint + Deadband + 2.1%. As humidity decreases, the compressor
demand will decrease to zero and turn off at Humidity Setpoint.
Variable Compressor Controlling Relative Humidity (IRDX):
Temp Control set to Return Air: The variable compressor starts at Humidity
Setpoint + Deadband. The compressor demand will increase 10% for each .2%
increase in humidity and reach 100% at Humidity Setpoint + Deadband + 2%. As
humidity decreases, the compressor demand will decrease to zero and turn off at
Humidity Setpoint.
Temp Control set to Discharge Air: The variable compressor starts at Humidity
Setpoint + Deadband and will run at 50% for the first two minutes. The compressor
demand will increase 10% for each .4% increase in humidity above the Setpoint +
Deadband + 1.1% and reach 100% at Humidity Setpoint + Deadband + 3.1%. As
humidity decreases, the compressor demand will decrease to zero and turn off at
Humidity Setpoint.
Variable Compressor Controlling Dewpoint
The variable compressor starts when dew point reaches Hi Dewpoint SP minus
1.0°F. The compressor demand will increase 10% for each 0.1°F increase in dew
point and reach 100% at Hi Dewpoint SP. As the dew point decreases, the
compressor demand will begin to decrease at Hi Dewpoint SP minus Hi Dewpoint
DB. It will reach zero at Hi Dewpoint SP minus Hi Dewpoint DB minus 1.0°F.
When dew point modulation has no demand, the Relative humidity logic may
determine compressor modulation (dew point modulation having the priority).
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