Are evaporative coolers more energy efficient than conventional airconditioners?
As a rule, evaporative airconditioners will use less energy than an equivalent “vapour compression” airconditioner. However, a fair comparison of these products is always fraught with difficulty. Evaporative airconditioners rely on the evaporation of water to cool the air (“evaporation is accompanied by a cooling effect”) and so increase the humidity in the cooled space. These types of systems are really only effective in dryer climates. Unlike conventional airconditioners (which remove moisture from the cooled space and work best in a sealed room), evaporative airconditioners require a large volume of fresh air to pass through the house, so ventilation to allow internal air to escape is essential. Evaporative airconditioners can also consume substantial volumes of water, so this is an issue to consider in many cases.
