2nd December 2011
This week started with a good look a heat pumps with the help of Keith Abdullah of Heat Pumps In Cambridge. As the name suggests Keith’s company are specialists in all types of heat pumps and if you are in the south east of England he is well worth getting in contact with. The issue we were trying to sort out is whether it is best to combine the passive solar warm air system with and air to air or an air to water heat pump. We came down on the side of an air to water system for the test site, however in simpler installations where the house was small a low cost air to air pump would probably be a better option. The latter would not require plumbing so would be as straightforward as adding a conservatory to an existing house.
As the weather gets colder fuel poverty is in the news again the impact of rising fuel costs on households. A new take on this story is the impact of renewable energy on conventional energy prices. There is obviously a problem here as people who live in houses that are difficult to insulate or who cannot afford solar panels are subsidising, in a big way, householders who are using solar PV as a way of getting a 10%pa return on £12,000.
What people should realise is that the government’s top priority is to reduce the peak demand on the electrical supply grid. Solar PV is one way to do this. Heat pumps, which would do a better job of heating people’s homes during winter, use electricity and therefore are less attractive from the government’s point of view.
Having spent some time helping companies market preventative health equipment – in particular diabetes monitors – it quickly becomes apparent that governments do not spend money looking for problems that cost large amounts of money to fix. This is especially the case where those problems go away if they are ignored. Unfortunately people spending the winter too afraid to switch on an electric fire are the energy market’s equivalent of the undiagnosed diabetics.
Selling Hot Air
We saw a warm air solar energy system installed in the US. ‘The solar wall’ is being used in a school and used to partially heat a gymnasium. The funding for the system is based on the amount of heat generated – along the lines of a feed in tariff for heat. The interesting aspect however is the growing realisation that warm air, passive solar heating, has an important role to play in the green building technology mix.
Warm Reception on a Cold Day
The end of this week saw the first day when there was significant daytime temperature difference between the inside and outside of the trial house. By luck the beginning of day was sunny and the conservatory made it up to 19C with the passive solar system at 32C and warm air coming into the house at 28C. This, with an overnight minus 1C and daytime temperature below 5C, was enough to keep the conventional heating off during daylight hours and the house at 20C. Performance would have been better if the sky had not clouded over during mid afternoon.
Have a good weekend – Peter Kruger
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