In undergrad out west, we didn’t have air conditioning. We had swamp coolers. Anyone who’s ever been in the inter-mountain west knows what I’m talking about; so the remaining 99% have no clue. A swamp cooler is a giant refrigerator size box that sits on top of your house (they do have funny looking window units). The tap water in the UtahMountains felt to be just barely above freezing; so what they do is run it through coils and blow air over it and through the house.