THX9321 & THX9421 Product Data
Table Of Contents
- Application
- Features
- Contents
- Specifications
- System Installation
- Installation Options
- Guidelines for Installing RedLINK Devices
- Installing Equipment Interface Module (if used)
- Wiring 24 Vac Common
- Selecting Discharge and Return Air Temperature Sensor Mounting Locations
- Selecting Return Air Temperature Sensor Mounting Location
- Installing Discharge and Return Air Temperature Sensors
- Selecting Thermostat Location
- Installing Wallplate
- Power Optional REDLINK™ Accessories
- Performing Initial Setup
- Linking Thermostat to Equipment Interface Module (if used)
- Linking RedLINK™ Accessories
- Completing Initial Setup
- Adding RedLINK Accessories to the Thermostat
- Locating the Connect Buttons on RedLINK Accessories
- Finding Your Password (Date Code) to Access Installer Options
- Installer Options
- Making Changes to Installer Setup
- Installer Tests
- Operation
- Setting the time/date
- Setting the fan
- Setting system mode
- Preset Energy-Saving Schedules
- Adjusting program schedules
- Overriding schedules: residential use
- Overriding schedules: commercial use
- Viewing equipment status
- Setting vacation hold: residential use
- Setting holiday/event schedules: commercial use
- Setting custom events: commercial use
- Setting holiday schedule: commercial use
- Setting holiday override: commercial use
- Initiating occupancy mode: commercial use
- Remote setback: commercial use
- Adjusting humidification settings
- Adjusting dehumidification settings: residential use
- Adjusting dehumidification settings: commercial use
- Adjusting ventilation settings
- Customizing screen color
- Setting preferences
- Cleaning the thermostat screen
- Adjusting security settings
- Viewing dealer information
- Advanced Features
- Installer options
- Using the temperature display
- Using the humidity display
- Universal Outputs (U1, U2, U3)
- Universal Inputs (S1, S2, S3, S4)
- Alerts and Diagnostics
- Heat Pump and Backup Heat Operation
- Indoor Air Quality (IAQ) Control
- IAQ Reminders
- Customizable Reminders
- USB Port
- Commercial Features
- Overriding schedules: commercial use
- Setting holiday/event schedules: commercial use
- Setting custom events: commercial use
- Setting holiday schedule: commercial use
- Setting holiday override: commercial use
- Initiating occupancy mode: commercial use
- Ramp Rates
- Custom Names
- Remote Setback
- Economizer and Time of Day (TOD) Operation
- Pre-Occupancy Purge
- Battery Replacement
- Optional Accessories
- Portable Comfort Control
- Remote Indoor Sensors
- Backup Control
- Replacing a Thermostat
- Replacing an Equipment Interface Module
- Wiring
- EIM Wiring Diagrams
- THX9321 Thermostat Wiring Diagrams
- THX9321 Thermostat Wiring Diagrams Using Universal Relays to Control Heating or Cooling
- Wiring IAQ Equipment or a Heat/Cool Stage to the Universal Terminals
- Economizer Module Wiring Diagrams
- Wiring C7089U1006 Outdoor Sensor
- Wiring guide — Wired Indoor Sensors
- Zoning
- Troubleshooting
- Regulatory Information
THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ WITH EIM
68-0311—02 102
INDOOR AIR QUALITY (IAQ)
CONTROL
Humidification
The thermostat reads the indoor humidity level and allows the
user to set a humidification setting with or without window
protection.
The thermostat can be set up to control a humidifier in any
system mode in the Installer Setup (ISU 8060). A discharge air
sensor is required to humidify in the cool mode.
If humidification and dehumidification are setup to operate in
the same system mode (Heat, Cool, Off) and you are sensing
humidity from one location, 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 different 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.
Window Protection
Window Protection limits the amount of humidity to prevent
frost or condensation on windows. Window Protection (ISU
8050) requires an outdoor sensor.
The maximum humidity level that is allowed (“Window Limit”) is
displayed on the Humidification Settings screen. The
thermostat prevents frost or condensation on windows by not
allowing the humidifier to run above the “Window Limit.” The
thermostat may turn off the humidifier before the desired
humidity setting is reached.The Window Limit is based on the
current outdoor temperature and the user's window protection
setting.
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 setting 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 windows require a lower
Window Protection setting, which will limit how much your
humidifier can run.
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 number and check for frost/condensation on
your windows the next morning. Continue to adjust the Window
Protection setting to a lower number until frost/condensation is
no longer present.
Fig. 206.
Fig. 207.
If Window Protection is turned Off, the thermostat controls the
humidity level to the user's desired humidity setting. Frost or
condensation may appear on windows.
Set up Humidification
1. Select the Humidifier Type at ISU 8000. See Fig. 208.
NOTE: Based on the humidifier type you select, the
thermostat defaults to the most commonly used
settings for that humidifier type.
For example, a Bypass or Fan Powered humidi-
fier will default ISU 8070 to “Humidify Only
when Fan is On.”
A Steam humidifier will default ISU 8070 to
“Humidify on Demand: Thermostat Controls
Fan.”
Fig. 208.