Evaporative Cooler Seasonal Setup

The evaporative cooler (swamp cooler) can be a great asset to a homeowner, if used correctly. As a residential handyman, I see many improper setups. I also see many people sweltering in the heat when a swamp cooler would easily take care of their cooling needs.

The first of the big four mistakes is a general misunderstanding of what an evaporative cooler is, and what it isn't. It is not just a cheap version of an air conditioner. They work in very different ways. Swamp coolers also work best in dry climates such as New Mexico, Colorado, or Nevada. You must also understand that these coolers work on the principle of air displacement. For the best operation you must open windows at the far end of your home from where the cooler is mounted. Too little free air flow will make it overly humid and stuffy, as well as decreasing your cooling potential. If you are one of the millions who bought the stand alone evaporative units from a home improvement store in the past few years, you will be more satisfied with your purchase if you set it in front an open window (as close as possible) and open another window in another part of your home. If you are drawing the air in, it needs to go out somewhere.

The second problem is improper maintenance of the evaporative pad(s). If you are in a harsh water climate, then consider supplying your cooler water from a filtered source. These pads clog after a time in any water condition, and replacing them when needed will greatly enhance the efficiency of your cooler. An old pad can also lose some of it's microbial resistance, thereby allowing small amounts of mold or mildew to grow. Anyone having seasonal allergies may be bothered. Also be sure to buy proper fitting pads. A four inch gap at the top of an intake panel will cut your cooling output by a large measure. The air follows the path of least resistance (in this case, around the pad) and lowers your efficiency rating.

The third trouble area is improper belt tensioning and/or replacement. Drive belts will eventually crack and glaze over. Proper belt tension guidelines are usually stamped on a decal on the blower housing or framework. Do not tighten a belt more than recommended. Doing so will cause excessive wear on the blower bearings and make the whole unit noisier. Don't forget to add a few drops of oil in each blower bearing at the beginning of the season. Depending on your make and model, you may or may not have a place to oil the electric motor bearings. (Caution! Over oiling creates a nasty mess to clean out of the water reservoir.)

The fourth problem can usually be overcome with a little ingenuity and some duct tape. This applies mostly to window mounted swamp coolers. I've seen many coolers mounted and operating with gaps of several inches between the housing and the window frame. There is no sense in cooling the air, only to have ten percent of it pumped right back outside. Take time to fit some panels around the part of your cooler that sticks into the room. In a pinch, use some heavy duty trash bags and duct tape (or any other heavy duty tape of your choice) to seal the gap. Whatever you do, make it water tight enough to shed rain, or an errant sprinkler. After all, you don't want to be replacing a window sill this fall, do you?

When the hot season is over be sure to drain the supply line to your cooler and empty the reservoir pan. Cover your cooler through the winter, but be careful when setting up for the next season. A mildly warm and protected cooler in the early spring is a favorite nesting place for yellow jackets and wasps.

Enjoy the days of summer . . . and keep your cool.