Honeywell THX9321 Prestige 2.0 System Installation Manual page 23

Southern Dehumidification Away Mode
Southern Dehumidification Away Mode protects the home when unoccupied for
long periods of time during hot and humid weather by maintaining the desired
humidity and temperature settings. Southern Dehumidification Away Mode
options: (ISU 9180 to 9200)
• Fan Control: Auto, On or Circulate
• Low Limit Temperature Setting: The thermostat allows the cooling system
to lower the indoor air to the Low Limit Temperature Setting to reach the
Dehumidification Setting (ISU 9200).
• Temperature Setting: Temperature that is maintained when dehumidification
is not needed.
• Dehumidification Setting: The desired humidity level while Southern
Dehumidification Away Mode is active.
You can control humidity with a dehumidifier or a cooling system. If a cooling
system is used, humidity is controlled by cooling indoor air to the Low Limit
Temperature Setting. When the desired humidity level is reached, the system will
maintain the Southern Dehumidification Away Mode temperature setting.
Ventilation
The thermostat can be set for the following ventilation types: (ISU 10000)
• ERV/HRV
• Passive (Fan Only)
• Fresh Air Damper
Ventilation Control Methods (ISU 10050)
Ventilation can be setup to meet ASHRAE or Percent On Time settings. To meet
these settings, the thermostat will ventilate during calls for heat, cool and fan. If
the required ventilation has not been achieved for ASHRAE or Percent On Time,
the thermostat will force the ventilation equipment on.
• ASHRAE: The thermostat operates ventilation equipment to meet the
ASHRAE 62.2 ventilation standard based on CFM, number of bedrooms,
and square footage of the house. ASHRAE 62.2 can only be met if the
ventilation equipment is running. If the ventilation equipment is off for any
reason (outdoor ventilation lockouts, set up to turn Off during Sleep period,
turned off by user etc.), ASHRAE 62.2 is not met during those times. See
ISU 10125 to select a Ventilation Priority.
• Percent on Time: The ventilator runs based on a percentage set in the
Installer Setup. For example: if set to 50%, the ventilator runs at random
times during a 1 hour period until it reaches a 50% run time (approximately
30 minutes).
THX9321/9421 Prestige
23
IAQ and RF EIM
®
69-2490—05