Condenser dryers
Heated air passes continually through the washing load. Instead of exhausting the air, the dryer uses a heat exchanger to cool the air and condense the water vapour into a drain or collection tank. The air is then reheated and passed through the load.
Vented dryers
Heated air is passed through the load, with the moist air vented out of the front of the appliance or through a venting duct.