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To check the humidifier’s operation, note the Control setting and set the
Automatic Humidifier Control to the test mode when the furnace blower
motor is operating. Water will flow into the humidifier for 1 minute and
then it will turn off. This insures the humidifier is operating properly. Do
not leave the Control in the test mode as it will not operate. Reset the
Control to it’s original setting.
TABLE 3 – Outdoor-Indoor Relative Humidity
Model EHUMD200ABM00B with Manual Humidifier Control
or Model EHUMD300ABA00B and EHUMD500APA00C with
Automatic Humidifier Control in Manual Mode:
(for Automatic Humidifier Control – see page 3)
The Manual Humidifier Control is installed either in the living area (typically
near the thermostat) or in the cold air return. The Automatic Humidifier
Control (in the Manual Mode) 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 recommended 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 (see Table 3) and experience as to what is best for the average
home. 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. For example, a wintertime indoor RH of 50%
may be considered ideal by some, 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 high relative humidities. This same condensation can take
place in other areas in your home with the possibility of damage resulting.
Outside Temperature
Recommended RH
+40°F
45%
+30°F
40%
+20°F
35%
+10°F
30%
0°F
25%
–10°F
20%
–20°F
15%
The Humidifier Control is a precision instrument that can be used to
determine the RH accurately in your home during the winter. Turn the dial
to the lower setting, then reverse the dial direction slowly until a “click” is
heard. At this point, read the RH on the dial. This will be very close to the
actual RH in your home.
EFFECT OF WATER CHARACTERISTICS
To check the humidifier operation, set the Humidifier Control above the
click point, make sure that the water saddle valve is open and that there is
electricity to the humidifier. Generally, the furnace and blower motor must
be operating for the Humidifier Control to function. After the humidifier has
operated for several minutes and water is entering the humidifier and coming
out at the drain, reduce the Humidifier Control setting below the click point
and the humidifier should automatically shut off. Now set the Humidifier
Control dial at the recommended inside relative humidity, depending on the
outside temperature. Follow the suggested settings prior to a drop in the
outside temperature.
Additional Information
Be sure to keep fireplace dampers closed when not in use. They provide
an excellent escape route for heat, as well as humidity. Humidity is lost
at an even faster rate than heat because water vapor tends to seek its
own level and your humidifier would not be able to replace it even when
running at full capacity.
On occasion, indoor moisture producing activities such as clothes drying,
cooking, showers, etc., may raise the relative humidity level higher
than it should be, even though the Humidifier is not operating. Telltale
indications, again, are condensation or frost on cold surfaces such as
windows, doors, walls, etc. If such condensation persists for several hours,
your home should be ventilated to dissipate the potentially damaging
excess moisture.
Your humidifier will operate effectively using either hot, cold, hard or
mechanically softened water. Whether to use available tap water, even
though it may be quite hard, or chemically softened water, is a common
concern to homeowners when installing a humidifier. Because of the
humidifier’s design, most of these solids are effectively controlled by
flushing them down the drain.
Water used in homes contains varying amounts of minerals. The residue
remaining as a result of hard water evaporation is primarily calcium and
magnesium components and is usually quite hard, scaly, and dense.
Residue from softened water tends to be soft and fluffy and has a greater
volume than hard water residue. The service life of a Humidifier Pad
may be extended by using hard water, but in either case, the Humidifier
Pad should be changed once a year. This is why proper maintenance
is important and necessary. Service hot water 140°F maximum, is
recommended with flow through, drain type units for increasing capacity.
