Evaporative cooling is the process of cooling air through the evaporation of water, which differs from typical air conditioning systems that use vapor-compression or absorption refrigeration cycles. The temperature of dry air can be dropped significantly through evaporation, which can cool air using much less energy than a traditional Air Conditioning / refrigeration compressor design. In dry climates, evaporative cooling can add more moisture to the air, increasing heat transfer. Evaporative cooling requires a water source and must continually consume water to operate. This design is rapidly growing alternative building facility level data centers cooling.