Manual Mode; Dehumidifier Control; If Dehumidification Is Installed; If Dehumidification Is Done With The Air Conditioner - Aprilaire Control4 User Manual

Indoor Air Quality functions
In manual mode it is important to anticipate a drop in outdoor
temperature and reduce the setting accordingly to avoid
excessive condensation. Use the following table to determine the
proper relative humidity setting.
Outdoor temperature/indoor relative humidity
Outside temperature
+50°F
+40°F
+30°F
+20°F
+10°F
0°F
-10°F
-20°F
Humidifier Control screen for humidification in manual mode

Dehumidifier control

If dehumidification is installed the thermostat can be configured,
through the installer set-up, to control dehumidification with
either a whole home dehumidifier or with the air conditioner
(cooling unit).
Press button to select Dehumidify and enter the
Dehumidifier Control screen.
4
Recommended relative humidity
50%
45%
40%
35%
30%
25%
20%
15%

Manual mode:

screen cycles
recommended
humidification
setpoints for
various outdoor
temperatures
Humidifier
adjustment
Humidification
setpoint
Indoor relative
humidity
Done button
(exit Humidifier
Control)
The thermostat will allow you to set the desired humidity (%
relative humidity) level in your home and can be used to turn the
dehumidification On or Off.
Use the dehumidification adjustment to set the dehumidification
setpoint to 60% when first installed. Allow dehumidification to
run until the initial setpoint is reached, before deciding if you
want to change the humidity setting.
Raise the setting if you prefer the air to be less dry; this will
reduce the amount of time that dehumidification runs.
Lower the setting if you prefer the air to be more dry; this will
increase the amount of time that dehumidification runs.
Your comfort is the best measure of how to adjust your setting.
When first installed, your dehumidifier has to remove all the
moisture that is initially in your home. The home acts like a
sponge so the moisture in the materials of your home is at the
same level as the air. After drying the air, the materials of the
home will release the moisture back into the air until they are
again at the same level. As a result, it is not uncommon for
dehumidification to operate for an extended period of time when
it is first installed.
Energy Saving Tip #1:
Adjust the setting to be as high as is comfortable to reduce
dehumidification run time – if it feels clammy or smells damp or
moldy lower the setting. To save energy, turn the dehumidifier
control OFF when you open your windows just as you would with
air conditioning.
Energy Saving Tip #2:
If vacating your home for an extended period in the summer, set
the relative humidity at 60% and set the cooling setpoint as high
as you are comfortable setting it to in cooling mode. Consult with
appropriate professionals regarding the highest temperature that
is safe for your pets or possessions. This will keep the humidity
at a controlled level to help prevent mold while minimizing the
amount of the cooling energy used.
Dehumidifier Control screen
If dehumidification is done with the air conditioner, the
thermostat will cool up to 3°F beyond the cooling setpoint for
dehumidification. Note overcooling may not be sufficient to meet
the dehumidification setpoint.
Dehumidifier
adjustment
Dehumidification
setpoint
Indoor relative
humidity
Done button
(exit Dehumidifier
Control)