Spec Sheet

THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ WITH EIM
68-0311—07 104
Fig. 215.
6. Select from one of the Humidification Control
Options (ISU 8070). See Fig. 216.
• Humidify Only when Heat is On
The thermostat turns on the humidifier only if the
heat is currently running and humidification is
needed.
• Humidify Only when Fan is On
The thermostat turns on the humidifier only if the
fan is currently running and humidification is
needed.
• Humidify on Demand: Thermostat Controls Fan
The thermostat turns on the humidifier and the
fan when humidification is needed.
• Humidify on Demand: Humidifier Controls Fan
The thermostat turns on the humidifier when
humidification is needed and the humidifier
controls the fan.
Fig. 216.
7. Set the desired lockout option. See Fig. 217.
Fig. 217.
NOTE: ISU 10140 gives the option to lockout venti-
lation during calls for humidification. This
helps maintain the desired humidity level.
Control Humidification Level
1. Press MENU, then scroll to select Humidification.
2. Press Auto to use the humidifier to maintain your
desired humidity level.
3. Press Off to turn off the humidifier.
4. Move the slider bar to the humidity level you prefer,
then press DONE. The humidification setting range
is
10–60% in 5% increments.
5. Press MORE SETTINGS if frost or condensation
appears on windows. A lower number adjusts
humidity to help prevent these problems. Use a
higher number if indoor air is too dry.
6. To adjust the Window Protection setting, press More
Settings from the Humidification screen. Window
Protection is set on a scale from 1-10. A setting of
“1” represents poorly insulated windows and a set-
ting of “10” represents well insulated windows. A
lower number automatically reduces the humidity to
help prevent frost or condensation on your windows.
Use a higher number if indoor air seems too dry. To
prevent frost/condensation on your windows during
cold outdoor temperatures, poorly insulated win-
dows require a lower Window Protection setting,
which will limit how much your humidifier can run.
7. After you set the Window Protection setting, check
for frost/condensation on your windows in the
morning. If frost/condensation is present, adjust the
Window Protection setting to the next lowest num-
ber and check for frost/condensation on your win-
dows the next morning. Continue to adjust the
Window Protection setting to a lower number until
frost/condensation is no longer present.
NOTE: The Window Protection option is only available if
an optional outdoor sensor is installed.
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 humid-
ity level.
If humidification and dehumidification are setup
to operate in the same system mode (Heat, Cool,
Off) and you are sensing humidity from two dif-
ferent locations using a remote wireless indoor
sensor, the thermostat will allow humidification
and dehumidification to operate at the same time,
and there is no deadband between humidification
and dehumidification settings.