Your 
® Humidifier
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, combines 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 maxi- mum allowable comfort all winter long.
The important considerations in the evaluation of a humidifier are Positive Control, Sufficient Capacity,
The Aprilaire Humidifier (except the Models 350 and 360) is installed to operate in conjunction with the furnace blower motor. When the humidistat or Automatic Humidifier Control calls for humidity and the blower motor is operating, water flows to the distribution pan located at the top of the unit. The water is uniformly distributed across the width of the pan and through a scientifically 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
The Models 350 and 360 use service hot water (140°F maxi- mum) for its heat source, as heat is needed for evaporation. While the water going to the unit is hot, the flushing water to the drain will be cold. The heat is extracted during the evaporation process.
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
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