Tumble Dryers - Overview

Issue

• Which types of tumble dryers are available in the market?
• What are the main differences between tumble dryers? 

Applies to

• tumble dryers

Resolution

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

Condenser Dryer with Heat Pump Technology - Most efficient in terms of energy consumption.

• 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

• 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:

	Condense Dryer with Heat Pump	Condense Dryer with Heater	Exhaust Dryer with Heater
energy consumption	lowest	low	above average
drying temperatures	low	high	high
drying delicacy	***	*	*
drying cycle time	***	**	*
energy saving*	***	*	------
performance drying cost	***	*	*

* compared to exhaust dryers

Tumble Dryers - Hints and Tips of Effective Use:

Problem: Drying time shown on the display does not correspond to real drying time
This is because the cycle time on the display: Is shown before the drying starts and does not include real-time sensor measurements does not include some important drying conditions like ambient temperature, initial laundry moisture, load mass and type is related to the average 5 kg loads of the cotton and jeans programs, and the respective recommended load of other programs.
Possible Cause and Solution
Possible Cause	Possible Solution
Dryer installation was not placed according to the installation requirements.	Assure optimal installation place - Read carefully the installation requirements in the user manual.
Too low or too high ambient temperature below 5°C or higher than 35°C.	Assure optimal room temperature  19°C - 24°C.
Too wet or even dripping laundry.	Spin the laundry well before drying.
Laundry loads exceed the recommended values.	Use only proper loads.
Humidity sensor does not correct setting.	Adjust remaining moisture laundry degree - See suitable procedure in the user manual. Download user manual.