Therma-Stor Products Group 90H - Manual (Page 8)

When the fan/filter switch is in the “ON” position, the motorized
damper will open and the fan will run, introducing outside air. The
unit may or may not be dehumidifying in the ventilation mode,
depending on the humidity control setting. See Section 4.7 for
humidity control operation.
4.6D Ventilation Timer and Humidity Control WITH
Fresh Air AND Motorized Damper
Refer to sections 4.7 through 4.9C.
4.6E DEH 3000 Digital Control WITH Fresh Air AND
Damper
Refer to Section 5.
4.6F DEH 3000 Digital Control WITHOUT Fresh Air
Refer to Section 5.
4.7 Humidity Control Adjustment
Set the humidity control to the desired
humidity level for the home. Turning the
knob clockwise results in a drier setting. See
the back of the control panel cover for set
points. The dehumidifier will run continuously
until the relative humidity (RH) is reduced
to the humidity control dial setting. Setting
the humidity control to lower RH levels will
NOT increase the dehumidification rate; the
unit will simply run longer to reduce the RH to the setting. The
UA-90H unit (and refrigerant-based dehumidifiers in general) will
reduce a warm space’s RH to a lower level than that of a cool
space. Therefore there is no benefit to set the humidity control to
excessively low levels in cool rooms; doing so will result in long
periods of ineffective dehumidifier run time. Settings below 45%
are not recommended.
4.8 Fan/Filter Switch
Turning ON the fan/filter switch will cause
the UA-90H fan to run continuously, whether
the UA-90H is dehumidifying or not. This
function is desirable if the unit is used for air
circulation and filtration to achieve maximum
indoor air quality. When the switch is ON; air
will be constantly filtered through the UA-90H
and circulated throughout the house. When
the switch is OFF the fan will operate only when the humidity
control calls for dehumidification or when the ventilation timer calls
for ventilation.
4.9 Ventilation Timer
The ventilation timer controls the fan and the motorized fresh
air damper. When the ventilation timer is activated, the UA-90H
will circulate the indoor air, and bring in fresh air from outside.
The ventilation timer should be set for the required ventilation
of the residence. The home should be ventilated with fresh air
as suggested by applicable codes and standards or as required
by the homeowner. The ventilation timer is an electronic timer
that displays the current time. This timer has battery backup,
so it will not require resetting after a power outage. Following
a prolonged power outage the display of the timer will flash on
and off indicating a power outage has occurred. The one-minute
time increments of the ventilation timer allow you to program the
ventilation of your home to fit your schedule.
The ventilation timer allows six programs with each program
having one “ON” and one “OFF” event. A program allows the
user to turn the ventilation on at a certain day and time, then it
allows them to turn the ventilation off at a certain day and time.
Each of these programs can be repeated daily or weekly or
during a specified block of days. All six of the programs operate
independently of each other. If the timer fails to operate or operates
erratically, check that the control panel receives 24Vac from the
UA-90H. If 24Vac is present at the control panel, reset the timer by
pressing the reset button at the bottom center of the timer face.
The reset button is the small recessed button with an R beneath
it located below the 1-7 and h buttons. Depress the reset button
until the display clears. Release the reset button. The display will
reappear as 00:00. Resetting the timer will clear the time and all
program settings. After resetting the timer follow the instructions
below to set the correct time and ventilation programs.
4.9A Setting the Time
Set the correct time on the timer by sliding the switch in the upper
right hand corner of the timer to the clock symbol. and pressing the
1-7 (DAY), h (HOUR), and m (MINUTE) buttons. Remember this timer
operates on a 24-hour (military time) clock.
4.9B Ventilation Schedule
Slide the switch in the upper right hand corner to the program
symbol P. “ON” will appear to the right of the time and the number
“1” will appear in the lower right hand corner of the display. The
“1” and “ON” signify the turn on time for the first program. Press
the 1-7, h and m button to choose the days of the week for this
program. You can choose Mon.-Sun., Mon.-Fri., Sat.-Sun., or any
single day of the week. The days chosen are shown along the top
of the display on the ventilation timer. Next press the h button to
FOR HVAC INSTALLER AND HOMEOWNER
Figure 3
Humidity Control
Adjustment Knob
Figure 4
Fan/Filter Switch
Humidity/Fan Control Panel
Part No. 4024155 Ventilation Timer & Humidity
Control Panel
Part No. 4024125
8 Ultra-Aire 90H Installer’s & Owner’s Manual 9 Ultra-Aire 90H Installer’s & Owner’s Manual