Starting out on my heat pump journey

[HML]

Anyway, heatpunk recons we have a heat loss 6916w at -3.2c, so a 7kW Aerotherm Plus should be sufficient. It also says our total annual demand is 16967 kWh a year, which seems at odds with our actual gas usage.

Our annual gas usage for 2023 was 9099 kWh, that was for heating, hot water and our gas hob.
For 2024 up to 19 December was 8587 kWh, gas hob was removed in July

Any thoughts on why heat punk differs so from much on past actual usage???

1 - the last 2 years have been rather warmer than average.
2 - you live in the south east so the heat punk outdoor temperature may be lower than your actual temperatures.
3 - your air change may be a lot better than that assumed by heat punk / MCS. There are discussions on the OEM forum about the MCS air change rates being too high and producing over estimated heat loss figures.

[Ronski]

Yes we've certainly had warmer winters, can't remember the last really cold one.

As for the ACH rates, I had adjusted them all down from what Heatpunk intinitally entered, I've seen mentioned previously that they are way too high. What I've used is shown in column F in the screenshot in my previous post.

[spread-tee]

Hi Ronski, I am starting to think along the same lines, we "only" have six zones for the heating but as we rarely have more than any 2 on at once I am thinking that the pipework will be fine, our largest zone is 3 pretty big rads fed from 22mm primaries and then 15mm secondaries. I would think you may get away without uprating loads of pipework if you have separate timings too.
I will follow your thread with interest.

Desp

[NoraBatty]

One thing to keep in mind, is that heatpumps can also cool the house. Whoever you speak to about install, ask them if they are able to design a system for optimum cooling as well as heating.

Ive not looked into it as dont need it up here, yet... but heatgeeks use theirs to cool their offices, and ours has a cooling option, but i dont know what is needed to maximise this feature, if anything.