Manual Mode; Relative Humidity - Aprilaire 350 Owner's Manual

-10
1 10
2 10
3 10
4 15
5 20
6 25
7 30
As an example, if the outdoor temperature is 20°F, and, following step 3,
the humidifier turns off at "5" on the dial range, then the RH in your home is 35%.
Manual Mode: (Automatic Mode – see page 3)
Your Aprilaire Humidifier Control is installed in the cold air return. It is
important to anticipate a drop in outdoor temperature and reduce the setting
accordingly to avoid excessive condensation. For example, with an outdoor
temperature of 20°F the correct setting will be 35% relative humidity. If the
temperature is expected to fall to 0°F that evening, then merely reduce the
setting to 25% several hours prior to the temperature change.
The recommended settings on the Humidifier Control are based on years of
research and experience (see Table 3). These settings represent a
compromise between RH levels that would be most desirable for comfort
reasons and humidity levels that are suitable for protection of your home and
to avoid condensation on your windows. For example, a wintertime indoor RH
of 50% may be considered ideal, but unfortunately, it probably would result
in damage to your home. Observance of the recommended RH levels on your
Humidifier Control, therefore, is an important safeguard. Condensation of
water on inside windows in the form of fogging or frost is usually an
indication of too much relative humidity. This same condensation can take
place in other areas in your home with the possibility of damage resulting.
TABLE 2 – % Relative Humidity Guide
Outdoor Temperature (˚F)
0
10
10
15
20
25
30
35
10 20
10 15
15 20
20 25
25 30
30 35
35 40
40 45
- 5 -
30 40
20 25
25 30
30 35
35 40
40 45
45 45
45 45
90-1080