Getting the Most Cooling From Your Swamp Cooler

Evaporative coolers work best when the outdoor air is hot and dry. These simple steps can make a noticeable difference in comfort and operating cost.

Source: Ed Phillips, Arizona Almanac

Start It Early

Turn the cooler on before the house becomes hot. It is much easier for the cooler to maintain a comfortable temperature than to cool walls, furniture, floors and ceilings after they have absorbed heat all afternoon.

Provide Proper Exhaust Venting

A swamp cooler brings large amounts of outside air into the house, so an equal amount must be allowed to escape.

Crack open windows in the rooms you want cooled. A useful starting point is opening each window several inches, then adjusting them until doors neither slam shut nor are difficult to open. Or place a sheet of paper on a screen of a window that is open, and if it sticks quickly and firmly, you need to open more windows. It should be easy to move it down the screen when set right.

• Too little opening restricts airflow and raises indoor humidity. This effectively lowers the performance of your cooler.
• Too much opening may reduce air movement in the rooms that need it and allow hot air to flow in through the open windows.
• Open windows farther in warmer rooms and less in cooler rooms.

If concerned about safety, you can buy window locks that prevent the windows from opening any further, or put a piece of wood in the track of windows that slide sideways.

Unlike refrigerated air conditioning, an evaporative cooler should not operate in a tightly closed house.

Block Direct Sunlight

Close blinds or curtains on the sunny side of the house before direct sunlight begins coming through the windows. Exterior shade screens, awnings and reflective window coverings can help even more because they stop heat before it enters.

Reduce Indoor Heat

During the hottest part of the day:

• Minimize oven and stovetop cooking.
• Use an outdoor grill, microwave, pressure cooker or air fryer when practical.
• Run clothes dryers and dishwashers in the evening.
• Turn off unnecessary lights and heat-producing equipment, although most low watt LED bulbs produce very little heat.

Keep the Cooler Maintained

Performance drops when pads are clogged, the belt is loose, water distribution is uneven or the pump filter is restricted. Proper maintenance helps ensure that:

• All pads are thoroughly and evenly wet.
• The pump and distribution tubes flow properly.
• The water level is correctly adjusted.
• The belt has proper tension.
• Bearings are lubricated where required.
• Mineral buildup and debris are removed.
• Airflow is not restricted.

Use the Pump Before the Fan

When possible, turn the pump on for approximately 3–5 minutes before starting the blower. This allows the pads to become wet before hot outdoor air is pulled through them.

Check Pad Wetting

Dry sections of a pad allow hot outside air to pass directly through the cooler. All pad surfaces should receive even water flow without large dry areas. Ensure the pads aren’t sagging or hot air can flow in over the top of them, warming the air coming in.

Keep Interior Air Moving

Ceiling fans or small circulating fans can improve comfort and help distribute cooled air, especially in rooms located farther from the cooler ducts.