Heat pump tumble dryers have been around for a few years, however it’s only recently that companies such as Miele have developed them so that they can offer an “A” Energy rating. This makes them the perfect choice if you want to save on energy bills and also want a more energy efficient and environmentally friendly way of drying you washing. You also don’t require any venting as all the moisture is collected via a floor drain.
The interesting thing is that although the name suggests the heat is produced by a heat pump, the science behind developing these appliances actually involves a refrigeration unit. This video explains how the whole process works.
Essentially heat pump tumble dryers work using two closed cycles; the process air cycle and the refrigerant cycle.
Process Air Cycle - The air is heated up and absorbs the the moisture contained in the clothes and linen and the condenser, then condenses the water contained in the air.
Refrigerant Cycle – This excess water is then pumped out and the residual heat from the water is used to supply the second closed cycle, the refrigerant cycle, with energy via a liquefier. The air which has been warmed by this cycle is then directed back into the tumble dryer and the air cycle begins again.
It sounds complicated but the process is pretty simple and it means that you can save up to 60% on the electricity running costs of the tumble dryer.
It will be a few years before heat pump tumble dyers are common place, but the technology is certainly working now and as with all new technologies it will only be a matter of time before we will see more and more heat pump driers in laundries.
