Set Up Ventilation - Honeywell Prestige 2.0 THX9421 Manual

Ventilation — Outdoor Condition
Lockouts (ISU 10130)
Ventilation will not operate when outdoor conditions
exceed the lockout settings unless you manually call for
ventilation or Ventilation Priority (ISU 10125) is set to
ASHRAE is Priority and ventilation is needed to meet
ASHRAE. Lockouts can prevent ventilation during extreme
weather conditions to keep humid, hot, and cold air out of
the home.
NOTE: This feature requires an outdoor sensor.
If the outdoor sensor also measures humidity, ventilation
will not be allowed when the outdoor dewpoint is above
the level you set. Options are:
• Ventilation Low Temperature Lockout Setpoint
(Off, -20° to 40° F)
• Ventilation High Temperature Lockout Setpoint
(Off, 80° to 110° F)
• Ventilation High Dewpoint Lockout Setpoint
(Off, 65° to 85° F)
Refer to the information below if you need assistance
setting the High Dewpoint Lockout.
• Higher than 80: Extremely uncomfortable
• 75 to 80: Very uncomfortable
• 70 to 74: Quite uncomfortable
• 65 to 69: Somewhat uncomfortable
Ventilate on High Indoor Humidity (ISU
10160)
If set to ventilate on high indoor humidity, the ventilator
turns on to remove excess humidity if the indoor humidity
is 10% above the Humidification setting. The thermostat
must be in the heat mode to ventilate on high indoor
humidity.

Set up Ventilation

Some screens shown in this section may not appear on the
thermostat, depending on how you set up ventilation.
1. Select the Ventilation Type in ISU 10000. See Fig.
253.
Fig. 253.
®
THX9321 PRESTIGE 2.0 AND THX9421 PRESTIGE
2. Select the terminals wired to the Ventilator (or Fresh
Air Damper). See Fig. 254.
3. Select the Ventilation Control Method. See "Ventila-
tion Control Methods (ISU 10050)" on page 114 for
more information. See Fig. 255.
4. Select the Ventilation Fan Control. See "Ventilation
Fan Control (ISU 10060)" on page 114 for more
information. See Fig. 256.
NOTE: ISU 10060 is only displayed if the Ventila-
tion Type is ERV / HRV. The thermostat con-
trols the fan if the Ventilation Type is Fresh
Air Damper.
115
®
IAQ WITH EIM
Fig. 254.
Fig. 255.
Fig. 256.
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