FJS Distributors: Ventless Laundry Store

How do condensing dryers work?

Conventional dryers heat and circulate air throughout the clothes, picking up lint and moisture, then passing it out of the residence. All that air and energy is then thrown out of the residence along with the energy it took to cool/heat that air in the residence. Then the residence has to reheat/cool that air again.

Water based condensers are popular in combination washer/dryer units. The air inside the machine is heated and circulated through the clothes, then passed through a chamber where the contact with a fine mist of cold water causes the moisture to condense. The condensate collects in the bottom of the chamber and is pumped down the same drain as was the wash water. The dry air is then re-circulated through the clothes to begin the process again. This is a sealed system with no discharge of heat, lint, or humidity.

The following is a more detailed description of this same process: The condensing tumble dryer has two air circulation systems: one for the drying air and one for the cooling air. The black arrows in the diagram to the left indicate the path of the drying air, and the white arrows indicate the room-temperature cooling air.

Drying Air (indicated by black arrows)

1. The air is heated by the heater.
2. It is then drawn through the drum, where it absorbs moisture from the clothes.
3. The air leaves the drum through the lint filter in the door and passes to the fan and on the condenser.
4. The saturated air passes through the condenser, where the moisture condenses out. The water runs down into the container, where it is either pumped up into the main container or flows out through a drain hose to a drain.

Cooling Air (indicated by white arrows)

The condenser is cooled by air at room temperature, drawn in through the back of the machine and blown through the condenser, exhausting through the grills at the front of the machine. If the machine is built in, air is drawn in through the gap between the floor and the underside of the machine.

NOTE: To ensure proper air circulation, the exhaust opening and adjacent areas should be kept free from lint, dust and dirt.

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