Aprilaire Series 800 Owner's Manual page 10

BLOwER ACTIVATION
The blower Activation feature provided with the Model 63 ADMC turns the
HVAC system fan on when there is a call for humidity .
AUTOMATIC MODE
During the first heating season, your ADMC needs to be set to match
your home's condition . The ADMC default set point is 40% RH . Follow
these steps when adjusting your control .
1 . For the first 24-48 hours of operation, it may be necessary to adjust the
set point for more or less humidity, depending on your personal comfort
and home's requirements . Refer to Table 6 – ADMC Operation guide .
2 . During the coldest portion of the first heating season, minor adjustments
may be necessary . This is dependent on your home's construction . Refer
to Table 6 – ADMC Operation guide .
TABLE 6 – ADMC Operation guide
Condensation on
Reduce the setting on the control by 5% .
windows.
Lack of humidity.
Increase the setting on the control by 5% .
Humidifier does Check that set point is higher than sensed humidity .
not turn on. Make certain HVAC blower is operating and humidifier is
On . If humidifier still does not operate consult a heating
contractor .
Humidifier won't
Turn ADMC Off . If humidifier continues to produce steam
shut off. (humidifier steam light On), disconnect main power to
turn off the humidifier and consult a heating contractor .
"OFF", "– – –" The humidity sensor is not connected or is short circuited .
and alarm symbol Consult a heating contractor .
are displayed.
"– – –" is The temperature sensor is not connected or is short
displayed.
circuited . Consult a heating contractor .
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The humidity in your home will
now be accurately controlled
to meet your needs and should
not need further adjustment
during future heating seasons .
The Aprilaire ADMC measures
outdoor temperature and
automatically adjusts the set
point to prevent condensation
and damage . Table 7 shows the
maximum Humidistat set point
the ADMC will allow for various
outdoor temperatures .
MANUAL MODE
If an outdoor temperature
sensor cannot be installed or the
application requires a specific
RH set point, the ADMC can be
configured to Manual Mode . In
Manual Mode, the humidifier
and control will maintain a
constant RH, regardless of
outdoor temperature .
It is important to anticipate a
drop in outdoor temperature
and reduce the setting
accordingly to avoid excessive
condensation . See Table 8 for
the recommended settings . These settings are based on years of research,
represent a compromise between humidity levels that would be most
desirable for comfort and humidity levels that are suitable for protection
of your home and to avoid condensation on your windows . For example, a
wintertime indoor humidity of 50% may be considered ideal for comfort, but
unfortunately, it probably would result in condensation, which can cause
damage to your home . Observing the recommended humidity levels on your
ADMC is an important safeguard . Condensation of water on the inside
surface of windows in the form of fogging or frost is usually an indication
of too much humidity . This same condensation can occur in other areas in
your home, possibly resulting in damage .
TABLE 7 – ADMC Maximum Set Point
for Outdoor Temperature
Outdoor Maximum
Temperature Setpoint
°F (°C) (%RH)
20 (-7) 35%
10 (-12) 30%
0 (-18) 25%
-10 (-23) 20%
-20 (-29) 15%
TABLE 8 – Outdoor Temperature and
Recommended Indoor RH Setting
Outdoor Recommended
Temperature Indoor RH Setting
+40°F 45%
+30°F 40%
+20°F 35%
+10°F 30%
0°F 25%
-10°F 20%
-20°F 15%
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