This is a quick note on my new ‘heat pump challenge’.
I wrote a couple of years ago about the heat pump challenge. This is the name of a citizen science project run by Carbon Co-op that took place in 2021-22. The idea is to run your gas boiler at a much lower flow temperature than you commonly see to find out how ready your home is for a switch to a heat pump. Although I wasn’t a participant of the project, I did something similar in my house in Dundee over the winter before I had a heat pump installed. Even if you are not thinking about a heat pump for now, it has an added benefit of making your gas boiler more efficiently and slashing your heating bill.
In my Dundee challenge, I reduced the flow temperature down gradually, from 60°C to 42°C. This time I’m starting from 45°C to see if it’s enough to keep the flat warm as we enter the colder months and if I can go even lower.
I’m also making a couple of tweaks to the challenge this time based on what I learned from my experience living with an actual heat pump.
1. Instead of adjusting the settings of thermostatic radiator valves (TRVs) to keep some rooms cooler in an effort to save money, I’m leaving all TRVs at the max setting (fully open) as you would do with a heat pump. The idea is to heat the whole flat evenly, and this way I should be able to find out if any of the rooms feels noticeably cooler than others and work out any radiator needs upgrade to cope with lower flow temperatures.
2. Instead of turning the heating off at night, I’m keeping it on 24 hours, just as you would with a heat pump, with the room thermostat setting lowered (set back) by just a couple of degrees overnight. I don’t know what effect this will have on the heating bill, but this is a tweak that makes a huge difference in the comfort level, so I reckon it’s worth trying.
I’ll report back in spring.