The penultimate phase of our home decarbonisation project is complete, and our home (which is also my office) is heated by an air source heat pump. Since it’s a fairly hot topic in the debate about the UK’s net zero ambition, I thought I’d keep a record of how we got here.
The plan has been years in the making, but when our old gas combi boiler was unexpectedly condemned in what I thought was going to be a routine gas safety check in November 2018, we needed to replace it quick (moral of the story: do not get your gas boiler checked in winter during a cold snap – it’s a job for summer), and I decided to wait until the 5-year warranty expired.
I heard a lot about how the running cost of a heat pump was quite high compared to gas heating in the UK (because of the country’s energy pricing policy), so I decided to use the intervening years to implement some measure to cut the electricity cost down, namely to get solar panels and a battery as well as become a member of Ripple Energy’s Kirkhill and Derril Water Co-ops.
Once our boiler was out of warranty, I started looking for potential installers at the beginning of the year. I found out that the company that installed our solar system was no longer doing heat pumps, and that our energy supplier Octopus Energy were not covering our area, so I had to widen my search. I contacted four companies for quotes, and while I waited for their replies, I contacted Home Energy Scotland, which oversees funding schemes in Scotland, to check what was available and if we were eligible.
Once we chose an installer and got their quote (by then it was May), we applied to Home Energy Scotland for a grant and an interest free loan, which was approved after a couple of weeks (much quicker than with our loan application for the solar system a couple of years ago (at the height of the energy price shock triggered by the Russian invasion of Ukraine).
We decided to get the work done in summer when we don’t need heating, and the installer did a couple of site visits before the work started in August. Ours was a fairly straightforward job as only three radiators needed to be changed and the pipes feeding the radiators were standard size so didn’t need replacing. The biggest issue was to find space for the kit (200-litre hot water cylinder, buffer tank, pumps, valves, expansion vessels, interface unit and pipework connecting the lot) to go in, but there was a cupboard which must have been an airing cupboard once, which had just about enough space to fit most of the equipment, with a small bits placed in another cupboard next to it. It would have been a five-day job if it hadn’t been for a bit of scheduling mishap, which meant the electrician could not come in the same week, but the system was commissioned the following Wednesday. There was a lot of drilling and banging for sure, but all in all no drama.
The whole point of getting the work done in summer was so that we didn’t need heating, which means that the heat pump hasn’t been doing much since then. I will report back in winter how it’s performing.