Question: how much water does evaporative air conditioner use?
Answer: Water and Energy Use. Swamp coolers need a constant supply of water. As water keeps evaporating from the unit to cool the air, more water needs to replace it. Most water use estimates range from 3 to 15 gallons / 11 to 57 litres per hour, with averages between 7 and 11 gallons / 26.5 and 40 litres.