Do evaporative coolers need fresh air?

Yes, evaporative coolers need fresh air to operate properly. Evaporative coolers use the process of evaporative cooling to reduce the temperature of the air in a space. This process requires the cooler to draw in fresh air from outside, which is then cooled by passing it over water-saturated pads. The cooled air is then circulated throughout the space. Without a steady supply of fresh air, the evaporative cooler will not be able to cool the air effectively.