Aprilaire 448 - Manual (Page 3)

I. PRINCIPLE OF OPERATION
With your purchase of a humidification system, you have
invested in a humidifier that operates on the evaporative
principle – nature’s own way of adding moisture – and will
provide the proper relative humidity all during 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 help you do exactly that.
Nature, in producing an invigorating comfortable April day, com-
bines just the right temperature and the right amount of moisture.
Aprilaire Humidifiers employ the same principle, with refinements, to
give you the proper relative humidity for maximum allowable com-
fort all winter long.
The important considerations in the evaluation of a humidifier are
Positive Control, Sufficient Capacity, Trouble-free Performance and
Minimum Maintenance. The operating principle of your Aprilaire
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 unit. The water is uni-
formly distributed across the width of the tray and through a scien-
tifically designed system of outlets. It flows by gravity over the
Water Panel
® evaporator, the heart of the unit. Dry, hot air is moved
through the moisture-laden Water Panel evaporator where the
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 unit. When the unit 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 opened or
closed. The minerals and solid residue not trapped by the replace-
able Water Panel evaporator are flushed down the drain. The drain
also eliminates the problems caused by stagnant water. This is the
most effective and least expensive method to dispose of trouble-
causing minerals.
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