Eco Heating by Exhaust Air Heat Pump

SuperHomer Bill Powell has taken an experimental approach to heating his 1950s semi detached house. It is all about putting every bit of warm air generated to good secondary use – including exhaust hot air from cooking, showering, appliances, solar gain and body heat.

In his hot water tank Bill has two coils. One coil gains its heat from an Exhaust Air Heat Pump. The other coil heats the water in the underfloor heating system.

The Exhaust Air Heat Pump itself cost about £2,000 before installation and for every one unit of electrical energy it uses it produces 3 units of useful heat in the form of hot water. The system sucks residual warm air from, for example, the utility room behind the freezer and kitchen cupboards next to the cooker.

Bill has written a very helpful report on Eco Heating by Exhaust Air Heat Pump where he uses his own home eco renovation as a case study. You can download this report below. Impressively, Bill’s house maintains a comfortable living environment with just 96kWh/m2 of incoming energy supply. A typical UK house consumes 247kWh/m2 on the supply side!

Bill has compared the energy performance of his house to that of 21 other eco homes in Cambridge. For low energy consumption, the house is beaten by only two properties. These were both built in 2010 and one has a Ground Source Heat, the other has an Air Source Heat Pump and both have MVHR. See the links below for more information.

Bill’s house, built in 1957, has qualified as a SuperHome by achieving a 68% reduction in carbon intensity through the measures installed during renovation.

More Information:

Eco Heating by Exhaust Air Heat Pump by Bill Powell 

22 Eco Homes Compared in Cambridge

22 Eco Homes Compared – explanatory notes



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