Some ideas to improve on the panel usage. 1. Their efficiency improves with size. Minimum i use is 800w to heat bedrooms and such and 1100 panels for north facing rooms or lounge. 2. Use on outside or coldest wall if you can. They create a better temp gradient. 3. Radiant heat is slow acting and temp sensors do not measure it correctly. With home assistant you can use timers to turn panels on and off every few minutes to allow for the time delay for heat absorption. You can use the climate entity to control the plugs and measure the temp increase per hour to modify their usage so that they maintain the temperature rate you want. This combination works like a very smart thermostat and can all be done from inside home assistant. The result is you never use them at their rated power continuously but get the desired result and COP is above 1.

IR heaters work really well in new buildings especially with the insulation you need .They can be installed with solar panels and batteries on a cheap tariff Flexible octopus 14.70p / kWh from 12.30 am to 7.30 am all other times 34.34p .IR heaters work better on the ceiling than walls

Thanks for posting , It would be interesting to hear what a Heat Loss survey predicts for heat energy needed to keep your home at that temperature. Also factor the HP & radiators materials & their foot print . The refrigerant especially R290 has a Global Warming Potential of 3 & R32 CWP 675 & R410A 2088 . So a multi split system running R32 or R410A can wipe out CO2 saving if the gas leaks. but a R290 monoblock is less intense. Also Riddle this : One 15Mw offshore wind turbine , costs ( all figures approx) £25M can run 10,000 homes with heat pumps. , The £5,000 grant for those 10,000 heat pumps is £50M which would buy 2 more off shore wind turbines, which is enough to heat those same homes on resistive heating . Is the Rare Earth metals & copper windings in 10,000 heat pumps more or less than 2 large windturbines? The Maintenance, & eventual replacement of the extra 2 windturbines is less than the maint of the 10,000 heat pumps too. AND there is more Spare electricity all summer . ( hydrogen/efuel for planes?) . Spend the £50m grant on the heat pumps , with another £50M from the home owners & you have expensive stuff sitting around doing very little all summer. So I'm not even sure Heat Pumps are greener that "more wind turbines". -- Unless we run out of wind turbine spaces. The cost of electricity at the Windturbine is less than 5p/Kwh & once the wire is there it delivers is self (unlike Pumping gas or coal / oil lorries) . So is it more the electricity pricing model , rather than science & ecology that is necessitating heat pumps? Alot of folk quote £250 for a heat pump service, which is high compared to , more dangerous, gas boiler. Heat pump service , like car service, should be a DIY activity.

Excellent summary Chris.

Very interesting

Hard to say if you should add HP. We did opposite order of experiments. Had HP, then added IR panels to some rooms, ran whole house hotter. If I could JUST use IR, maybe would've but the HP is really nice too, just uses much more energy as our primary heat.

A sound conclusion Chris and agree with your thoughts. You would benefit from the £5K BUS scheme if you had a heat pump, I think £10K for a good installation would be the figure you were looking at. I guess the longterm factor we cannot control is the unit cost of electricity and how that plays into the pricing / cost benefit model. A topic for a regular review I guess.

Very detailed data. Are the IR panel sizes working well in each room? Or under or over spec'd anywhere? Pondering trying IR in couple of rooms as a starter

If I understood your numbers, during the coldest month you used an average of under 2kW for heating. How about a small air-to-air heat pump to provide about that much in the middle of your house, and keep the IR heaters to warm any cold spots and as a boost for really cold days. I've just had a 3kW unit (that's the output) installed for about £2,000 and it claims a COP of nearly 5. It's not eligible for a grant though, and it can't do hot water.

Hi thanks for video, very interesting, what do you use to measure you external temperature with the high and low figure?

where to get in the USA?

Amazed you only used 5000kwh per year.. I have a 1930 semi which uses 19000kwh of gas!! What standard of house insulation do you have?