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THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ 2.0 WITH EIM
68-0311—01 74
Control Dehumidification Level
1. Press MENU, then scroll to select Dehumidification.
2. Press Auto to use the dehumidifier or cooling system to
maintain your desired humidity level.
3. Press Off to turn off dehumidification.
4. Move the slider bar to the humidity level you prefer, then
press DONE. The dehumidification setting range is
40–80% in 5% increments.
5. If your air conditioner is used to control humidity, the
thermostat may use the following methods to maintain
your desired humidity:
• Cool from 1° to 5° F lower than your temperature
setting.
• Run cooling for the minimum “on” time to reduce
humidity.
• Run cooling and heating at the same time to reduce
humidity without lowering the temperature.
6. Press MORE SETTINGS to review or change settings for
the dehumidifier filter timer.
NOTE: If humidification and dehumidification are setup
to operate in the same system mode (Heat, Cool,
Off) and you are sensing humidity from one loca-
tion, the thermostat will automatically enforce a
15% deadband between the humidification and
dehumidification settings. The thermostat will
automatically switch between humidification and
dehumidification to maintain the desired humidity
level.
If humidification and dehumidification are setup
to operate in the same system mode (Heat, Cool,
Off) and you are sensing humidity from two differ-
ent locations using a remote wireless indoor sen-
sor (for example, main level and crawl space), the
thermostat will allow humidification and dehumid-
ification to operate at the same time, and there is
no deadband between humidification and dehu-
midification settings.
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 either 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 thermostat operates ventilation equipment based on a
percentage entered in the installer setup (ISU 10120). For
example if Percent On Time is set to 50%, the ventilation
equipment will run at random times during a 1 hour period
until it reaches a 50% run time (approximately 30 minutes).
Default setting is 30%. Range is 10% to 100% in 10%
increments.
Ventilation Fan Control (ISU 10060)
• Thermostat Controls Fan
The thermostat turns on the ventilator and the fan when
ventilation is needed.
Press MENU
Scroll to select DEHUMIDIFICATION
Set humidity to desired level
Press to review filter timer