Why I removed a gas boiler for an air source heat pump (ashp).

 I think, where practical, all new builds that require heating should have heat pumps installed. Existing buildings requiring retrofit installation can be more challenging.

If our personal existing heating used direct electrical heating, electrical storage heaters or some inefficient coal or oil heating it would have been a very easy decision to go ahead and get an air source heat pump installed, so long as we had the necessary space and financial capabilities for the initial capital costs. We do have the space and the upfront costs were helped by the financial incentives from the government but we had a fairly efficient 10 year old gas boiler. The decision therefore required a bit more justification but nevertheless a very worthwhile thing to do and proved to be so.

The five points below were my main reasons to replace my gas boiler in the first place but there were some unexpected additional advantages that materialised. I will deal with the first two that were motivations based purely on environmental concerns in this post and the other three will be incorporated in future posts along with the additional advantages.

The motivations:-

1. To reduce our carbon footprint.

2. Using electricity instead of gas helps to contribute towards energy companies and government being incentivised to plan for the building of more renewables.

  Also to gain first hand experience in order to obtain data and evidence, be more informed and in turn offer contributions on issues such as:-

3. Evaluating opposing opinions about ashps. (Identifying possible myths)

4. How to maximise layout  and other installation issues in retrofit situations.

5. How to optimise the control settings as a consumer in order to maximise efficiency AND further reduce consumption. (By optimising I mean not just finding the best compromise but getting the best of as many worlds as possible.)

The Environmental motivations:-

Some installers I initially contacted expressed reluctance at changing a gas boiler for an air source heat pump. However I believed these were based on short term financial costs to the consumer which may be already dated in the light of new gas prices. Regardless, let's look at the environmental issues based on reducing carbon emissions:-

If gas is burned in a modern gas boiler it will do so around twice as efficiently compared with burning gas in a power plant to make electricity. (Basic laws of thermodynamics make this so.) Under these circumstances alone it would make no environmental sense to replace a domestic gas boiler with direct electrical heating if all the extra electrical energy was created by burning fossil fuels. However modern heat pumps typically have efficiencies of over 300% due to the environmental yield created from the air, water or ground, even in the typical British winters. (I now have the personal experience to verify these claims.) So based on overall efficiency from fuel to heat in your home, ashps will create less greenhouse gases than burning gas in a power station. In addition the grid in Scotland is much cleaner than that since most electricity comes from renewables and so even more reason to replace gas boilers. However here lies a problem:- There are stubborn areas in our energy demand such as transport, home heating and some industrial processes that are difficult to decarbonise. If we are already meeting near 100% of our electricity demand from renewables, energy companies will only be incentivised to expand our renewable infrastructure including storage if consumers move from these stubborn energy demands to electricity. So replacing a gas boiler with an air source heat pump will help us play our part in giving energy companies and government the incentive to create a lower carbon overall energy policy.

Link page for further or future related posts.

If  thinking of making changes to your home heating it is best to get impartial advice.
In Scotland I would strongly recommend Home Energy Scotland.