Indoor Air Quality System Settings Tables; Humidifier System Settings Table; Dehumidifier System Settings Table - Aprilaire 8840 Safety & Installation Instructions

SETUP & TESTING

INDOOR AIR QUALITY SYSTEM SETTINGS TABLES

The following tables contain the Indoor Air Quality system settings and their details . Default settings are shown in
bold . Some settings are only present dependent upon the value of other settings .
The use of an outdoor temperature sensor (recommended) enables additional Indoor Air Quality functionality .
Please refer to the Model 8840 Owner's Manual for further information about thermostat features .
Note: Refer to manuals for humidifier, dehumidifier, air cleaner, and ventilation products for recommended
installation and operation .

Humidifier System Settings Table

System setting Description
Humidifier Installed? Selects if a humidifier is installed . Yes/On HVAC is
used for applications where the humidifier is installed
on the HVAC duct . Yes/Standalone is used for
application where the humidifier is independent of
the HVAC system . (If set to no, no other humidifier
settings will be available .)
Display Button? Note: Only available if Humidifier Installed is set
to No .
Outdoor Temperature Sensor Installed? Select if outdoor sensor is attached or not .
Humidifier Mode Selects auto or manual mode . Auto mode controls
humidity based on the humidity setting and outdoor
temperature . Manual mode controls humidity based
on the %RH setpoint . (Auto mode is only available if
outdoor sensor is set to Yes or Automation .)
Allowed Humidifier Operation Selects when humidification is allowed to occur
relative to heating and fan operation . Without Fan
allows humidification to occur without the HVAC fan .
This option should only be used when the humidifier
is independent of the HVAC system . Note: Without
Fan is only available when Humidifier Installed is
set to Yes/Standalone .
CAUTION: When Humidifier Operation is set to Without Fan the thermostat will turn on humidification
without energizing the HVAC fan . Do not select this option when the humidifier is installed on the HVAC duct .
Without airflow moisture can accumulate in the duct resulting in significant damage .
Humidity Deadband Select the minimum difference between the
humidifier and dehumidifier setpoints . (Only available
if both a humidifier and dehumidifier are installed .)
Humidifier Reminder Selects when the "Change Water Panel" message is
displayed .
Single or First Reminder Appears Determines the month the first (or only) "Change
Water Panel" message is displayed .
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SETUP & TESTING
System setting
Second Reminder Appears
Factory default setting
(bold) and setting range
No
Yes/On HVAC

Dehumidifier System Settings Table

Yes/Standalone
System setting
Dehumidifier Type Installed?
Yes
No
No
Display Button?
Yes
Auto
Disable Dehumidification During
Manual
Cooling?
Dehumidifier Forces Fan?
Heat Only
Dehumidifier Overcooling Limit
Heat or Fan
Forces Fan
Without Fan
Dehumidifier Reminder
Number of Months for Recurrence
Dehumidify in Vacation Hold?
10%
Vacation Hold Low Temperature Limit
10 to 20%
Off
300h Valve
Humidity Deadband
600h Valve
1 per season
2 per season
October
November
December
January
February
March
April
May
June
July
August
September
Description
Determines the month the second "Change Water
Panel" message is displayed .
Description
Selects if a dehumidifier is installed . (If set to None,
no other dehumidifier settings will be available .)
Note: Only available if Dehumidifier Installed is set
to None .
Selects if a dehumidifier is disabled during a cooling
call .
Selects if dehumidification can turn on the fan .
Selects the amount of overcooling that can occur for
dehumidification . (Only available if dehumidifier type
is set to Air Conditioning .)
The period for displaying the "Dehumidification
Service Reminder" message .
Select number of months for displaying reminder .
Selects if dehumidification with the air conditioner is
done in vacation mode .
Sets the lowest temperature the air conditioner
will cool to, to meet RH setpoint in Vacation Mode .
(Only available if dehumidifier type is set to Air
Conditioning .)
Select the minimum difference between the humidifier
and dehumidifier setpoints . (Only available if both a
humidifier and dehumidifier are installed .)
Factory default setting
(bold) and setting range
October
November
December
January
February
March
April
May
June
July
August
September
Factory default setting
(bold) and setting range
None
Whole Home
Air Conditioner
Yes
No
Yes
No
Yes
No
1°F (0 .5°C)
2°F (1°C)
3°F (1.5°C)
Disabled
Enabled
12 Months
1 to 12 Months
No
Yes
75°F (24°C)
70 to 85°F (21 to 29 .5°C)
10%
10 to 20%
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