Manual Mode - Aprilaire 300 Owner's Manual

MANUAL MODE

FIGURE B: ADHC (MANUAL MODE)
When installed in the Manual mode (see FIGURE B – internal switch
in MAN position and M in the display), 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% RH. If the
temperature is expected to fall to 0°F, then reduce the setting to 25%
several hours prior to the temperature change.
See TABLE 1 for the recommended settings. These settings, which
are based on years of research, represent a compromise between
RH 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 RH 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 RH
levels on your humidifier control
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.
8
TABLE 1: OUTDOOR
TEMPERATURE/INDOOR
RELATIVE HUMIDITY
Outside
Temperature
+40°F
+30°F
+20°F
+10°F
0°F
-10°F
-20°F
90-1236
Recommended
RH
45%
40%
35%
30%
25%
20%
15%