Tumble Dryers - Overview

Issue

• Which types of tumble dryers are available in the market?
• What are the main differences between tumble dryers?
• Which dryers are the most effective in terms of energy consumption?

Applies to

• Tumble Dryers

Resolution

There are three main types of Household Tumble Dryers sold on the market:

- Most efficient in terms of energy consumption.

Condenser Dryer with Heat Pump Technology

• Drying air is heated by the hot side of the heat pump.
• Hot air passes through the load and causes water evaporation.
• Water vapour is condensed by the cold side of the heat pump and collected into a reservoir or directly passed to the drain pipe.
• The heat pump's hot side re-heats the air afterwards for reuse, which conserves much of the heat within the dryer.
• A portion of the water vapour and heat leaks outside and increases the ambient temperature.
• After some time air in the internal loop is warmer and more humid which can increase the drying time.
• Heat re-circulation is the big advantage of this type of dryer, with a positive effect on energy consumption.

Condenser Dryer with Heater

• Drying air is heated by the heater.
• hot air passes through the load and causes water evaporation.
• Water vapour is condensed by the heat exchanger and collected into the reservoir or directly passed to the drain pipe.
• The heat exchanger is cooled by the forced stream of ambient air.
• A portion of the water vapour and heat leaks outside and increases the ambient temperature.
• After some time in operation air in the internal loop is warmer and more humid, which can increase drying time.

Exhaust Dryer with Heater (currently discontinued)

• Drying air is heated by the heater.
• Hot air passes through the load and causes water evaporation.
• Hot air carrying water vapour is exhausted outside the room through the ventilation hose.
• Heat is wasted, causing high energy consumption and hence high drying costs.
• After some time air in the internal loop is drier, decreasing drying time.

Tumble Dryers Comparison:

* compared to exhaust dryers