If you live where summers are hot and dry, evaporative coolers (also known as swamp coolers) can keep your home comfortable less money than air conditioner. Swamp coolers employ evaporating water to reduce the temperature of air that is drawn into your home by a large fan inside the cooler. But this process also consumes water. So which is more costly: the large electrical consumption of a central air conditioner, or the combined electrical and water consumption of an evaporative cooler?
The University of Arizona recently performed a study of evaporative cooler water use. They found that the cost of water consumed by these efficient low-tech appliances added only a minimal cost to their operation, especially when compared to power-hungry air conditioners. The study showed that the typical evaporative cooler consumed about 1500 kilowatt-hours of electricity per summer, costing about $150 at current rates. The cooler’s water consumption added an average of $54 to a municipal water bill over the course of the summer, for an electricity-and-water total of $204 per year. The central air conditioners in the study consumed an average of 6000 kilowatt-hours of electricity per summer, or about $600 at current rates. That $400 savings, year after year, makes evaporative coolers an attractive option for families all across the sun belt.
The use of low energy cooling methods such as evaporative coolers has an important added benefit for consumers and utility companies alike. Air conditioning adds a large summer “peak load” to the electrical grid when the system can least support it. Those hot afternoons in July and August, when everyone wants air conditioning at once, are when we are most likely to experience “brownouts”. You can do your part by using simple cooling measures such as evaporative coolers, room fans, or window shades to reduce your use of air conditioning, and you’ll save money in the process.