In arid climates, some homes are cooled by evaporative coolers, sometimes called swamp coolers or desert coolers. The devices use the evaporation of water to cool the air sent into the home, and are most often connected to the home water supply to maintain water in the cooler’s reservoir. The refill valve for the reservoir occasionally fails to close, causing a constant stream of water to enter the reservoir and drain out the overflow line. The overflow line is often connected to wastewater drain, allowing the leak to persist for months or years before the water waste is detected. The cooler can be easily checked for leaks by shutting off the equipment, and observing any water draining through the overflow line. Leaking coolers can usually be repaired by simply replacing the refill valve, re-circulation pump, or water lines.
Evaporative cooling is a very common form of cooling buildings because it is relatively inexpensive and requires less energy than many other forms of cooling. Unfortunately, evaporative cooling requires an abundant water source, and is most effective in climates with low humidity. In almost all climates, large buildings often use indirect evaporative cooling in cooling towers for the chillers in the HVAC system. Manufacturing and industry often use evaporative cooling technology to remove excess heat from machines, compressors and other equipment. In dry climates, the installation and operating cost of an evaporative cooler can be much lower than air conditioning, often by 80% or more.
In moderate humidity locations there are many cost-effective uses for evaporative cooling, in addition to their widespread use in dry climates. For example, commercial kitchens, laundries, dry cleaners, greenhouses, loading docks, warehouses, factories, construction sites, athletic events, workshops, garages, kennels and confinement farming (poultry ranches, hog, and dairy) often employ evaporative cooling.