Which is better – air conditioning or evaporative coolers?


by Bryan Updegraff, M.D.

The importance of controlling the environment in the home has been emphasized elsewhere. It is vital to the allergy patient’s attempt to relieve symptoms. Controlling the air that enters the home is the most important factor in this equation.

We emphasize to patients that closing the windows to keep the pollen, dust, and mold out of the home is vital. Air conditioners are preferred over evaporative coolers in general, because they recirculate the air, which can be cleaned. Air can then be filtered either at the source by a central HEPA filter system, at the ducts, or later with free-standing units.

Unique to Arizona is the efficiency and popularity of evaporative coolers. These systems are less expensive to run and have the added benefit of not excessively drying the air, so that allergy patients who have sensitive, dry skin can feel more comfortable. They have the disadvantage of introducing into the home outside air which is more or less filtered, depending on the status of the pads in the system. The traditional padding is the so-called aspen filters. This is aspen wood, which may be quite thin, and does a poor job of filtering particles. As these systems age they may not totally be moistened and then, essentially are non-existent filters. They expose the patient to the environment he is trying to avoid.

Recent improvements in evaporative coolers use a single inlet system and an improved filtering system based upon a cellulose (almost cardboard) material which is thicker than aspen pads. It is claimed that these filters can actually filter out substances down to 10 micron size, and represent a significant step forward to those individuals who would like to use evaporative coolers.

Whatever system you choose needs to be well maintained. Evaporative systems should be checked by maintenance people and the air conditioning system’s filters can be changed frequently.

Posted in: Home Environment

Allergy and the Environment