This is the most widespread dehumidifier technology. It works with a condenser whose temperature has been lowered by a refrigerant gas. When humid air is sucked up by the fan and touches the condenser, it is turned into liquid and flows into the tank. These appliances are adapted to all rooms (from 20 square meters to warehouses) as well as swimming pools, hot tubs, the latter requiring specific products because of the high chlorine concentration of the air. To sum up, they are powerful and efficient dehumidifiers.