User's Manual

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With your purchase of this humidification system, you have invested in a
humidifier that operates on the evaporative principle – nature’s own way of
adding moisture – providing optimum relative humidity throughout the
heating season. It is very possible that you have questions concerning your
new humidifier – questions on what it can do for you, and what you should
do to receive maximum benefits from it. This booklet is intended to answer
these questions.
Nature, in producing an invigorating comfortable April day, combines just the
right temperature and the right amount of moisture. Aprilaire Humidifiers
employ the same principle, with refinements, to give you the optimum
relative humidity for maximum allowable comfort all winter long.
The important considerations in the evaluation of a humidifier are precise
control, sufficient capacity, trouble-free performance and minimum
maintenance. The operating principle of your Aprilaire humidifier provides
all of these advantages. Here, briefly, is the method:
The Aprilaire Humidifier is installed to operate in conjunction with the furnace
blower motor. When the Aprilaire Humidifier Control calls for humidity and
the blower motor is operating, water flows to the distribution tray located at
the top of the humidifier. The water is uniformly distributed across the width
of the tray and through a scientifically designed system of outlets. It flows by
gravity over the Water Panel
®
evaporator, the heart of the humidifier. Dry, hot
air is moved through the moisture-laden Water Panel evaporator where
natural evaporation takes place. The now-humidified air carrying moisture in
vapor form (nature’s own way) is circulated throughout the home.
The correct water flow is determined by an orifice equipped with
each drain type humidifier. When the humidifier is operating, there
will be a small, steady stream of water to drain, which flushes
away most of the trouble-causing minerals.
Do not use the saddle valve to regulate the water flow. It is designed
to be completely open or closed.
The minerals and solid residue not trapped by the replaceable Water Panel
evaporator are flushed down the drain in the Models 500, 600 and 700. This is
the most effective and least expensive method to dispose of trouble-causing
minerals. The drain also eliminates the problems caused by stagnant water.
There are some homes where drain facilities are not accessible or available.
For these situations, or where high water hardness is not a problem, the
newest Aprilaire, Model 400, is designed to satisfy these applications.
TABLE OF CONTENTS
PRINCIPLE OF OPERATION