Together with being more energy and cost efficient, evaporative coolers have several benefits over air conditioner. The 1st being that because they lower the temperature of their environment rather just blowing cold air into it, doors and windows can get left open without jeopardising the final potency. They need no structural adjustments to buildings as they can be fixed to a roof, window or wall. They don't require any chemicals to filter the air as it's taken naturally from outside of the building. This not only makes it better for the environment, it's fitter for those in the building as they are still inhaling the unpolluted air from outside. Bacteria can't form as the temperature of the water in the cooler is too low.