Profile: Cooleasy Ltd. offers dehumidifiers, air conditioning units, electric heaters and heat pumps. Evaporative air coolers work using evaporation to cool the air, because the only moving parts in a swamp cooler are the water pump and the fan they are almost silent to run, lightweight and portable as well. Evaporative coolers work by air being passed over a moist honeycomb material, the warm air from the room will evaporate the water on the honeycomb, this evaporation uses heat energy in the air so that the air coming out of the cooler will be colder than the air coming in.