FOR HVAC INSTALLER ONLY AND HOMEOWNER

Operation

The initial dead band setting (the range that the dehumidifier cycles on and off) is 3%. With a setpoint of 50%, the dumidifier turns on when the reading reaches 53%. The dehumidifier continues to remove water from the air until the reading is 47%. The dehumidifier remains off until the reading is 53%.

If the setpoint is equal to or greater than the current ambient condition, the space does not need to be dried so the dehumidifier function will be off.

Example: Setpoint: 50% RH

Current condition: 45% RH = Dehumidifier off, the “O” indicator will not be shown.

If the setpoint is less than the ambient condition, the dehumidifier will be on and the red “DEHU” indicator will be lit. Since the space is more humid than the set point, the controller operates the dehumidifier to dry the space.

Example: Setpoint: 50% RH

Current condition: 55% RH = Dehumidifier on, the “O” indicator will be shown.

To set the relative humidity setpoint, press up or down “RH” buttons to adjust the relative humidity setpoint as desired. Therma-Stor recommends relative humidity levels not exceed 50% in the summer, and 25-35% in the winter if you live

in a cold climate. It is not recommended that the humidity setpoint be set below 35%. In order to dry the home in the winter in a cold climate, use the ventilation function of the system rather than the dehumidifier function. Call the factory or refer to the owner’s manual for more information.

5.3F Fan Setting and Operation

Use the “FAN” button to adjust the fan operation. There are 2 choices for fan operation: “ON” or “AUTO.”

“ON” – indicates the fan of the Ultra-Aire will run continuously. This does not affect either the dehumidification or ventilation functions of the system. In other words, the system may or may not be ventilating or dehumidifying while the fan is running. Common reasons for operating the fan

continuously are filtration and air recirculation.

“AUTO” – indicates the fan will run when the control calls for dehumidification or ventilation. If the control has not called for dehumidification for 3 hours, the control will automatically run the fan for 10 minutes. The fan must run a specific amount of time per day. This helps to keep the dehumidifier dry.

After dehumidification cycle, fan automatically shuts off for 10 minutes.`

To set the operation:

1.Press and hold the “FAN” button. The current fan setting will begin to flash. Release the button.

2.Press the “FAN” button to toggle between the “ON” and “AUTO” modes.

An “O” indicator indicates the fan is operating. A flashing “O” indicator indicates the fan is in a wait mode and will operate shortly. No “O” indicates the fan is off.

With the fan in the “auto” mode, the fan will operate only when needed by other functions of the system. The fan will remain off unless the system is dehumidifying and/or ventilating. The fan always runs during dehumidification and ventilation and the fan “O” icon will be lit. To completely turn the system off, use the “ON/OFF” button as described earlier. To adjust the ventilation mode see Section 3.7.

5.3G Damper Operation and Setting (Ventilation) Manual/Hold Mode

Ultra-Aire units can be installed to incorporate optional ventilation. The damper setting controls the ventilation function of the system. It has no control over the dehumidification function, although the ventilation function can and should be used to dry the space depending on the climate and the outside air conditions. Refer to the appropriate Ultra-Aire manual for more information.

In order to provide ventilation, the damper must be open (“ON”) and the fan must be running. The controller takes care of these two functions automatically, so that whenever the damper is open (“ON”), the fan is running.

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Ultra-Aire XT150H Installer’s & Owner’s Manual

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Therma-Stor Products Group XT150H owner manual 3F Fan Setting and Operation