The main point today seems to be not to over heat any room, and to only heat as required. Oil and gas fires or boilers are expensive, so it works out cheaper to have one central unit, I looked at storage heaters and can't for life of me work out how these are classed as central heating, as in the main they are individual units.
I know working abroad for many years the heat pump was the same, all AC's seemed to be a standard size and fitted in boxes in the wall
it seemed all a standard size and you could mix and match makes. Although some did reverse motor to heat, many used elements for heating, but main point is it was not central heating, but individual units for each room.
It does seem silly to have a cooling and heating system split when the heat transfer unit can work either way, so the first thing would seem all radiators need swapping for fan assisted, heat raises so heating units tend to be on floor, cooling units on the ceiling, but with fan assisted it does not matter.
Under floor cooling does not really work, so under floor heating is really out, as will only work in one direction.
To heat water all we need is an immersion heater, and if we have a transfer tank, then we can have multi fuel
to be frank my father-in-law had solar water heating in North Wales and it was a flop, daughter has it in Turkey and it works well, at what latitude solar heating stops working I don't know.
However my mothers house even in the winter had a problem with bay windows causing the living room to over heat, the main problem was only got the heat if the sun came out, so reaction time was important, wanted the radiator only just hot enough, so it would cool rapid if sun came out, the modulating gas boiler needed setting so it did modulate. And under floor heating was a non starter as too slow to react to extra heat when sun came out.
This was an eye opener to me, my own house did not have a problem when sun came out, so never even thought of the problem. Again my old house the living room had a Myson fan assisted radiator a standard radiator, and a gas fire, so around 10 kW of heating, whole idea of geofencing was not required it could heat the room from cold that fast.
But the big question is if we still want "central" heating? I looked at improving control of the central heating, to improve reaction time fan assisted radiators seem good, but they don't restrict the flow, so to work a modulating boiler needs piping in series not parallel, so we are in real terms ripping all out and starting from scratch.
So looking at cost, my oil costs around £350 per annum, with better insulation and control that can likely be reduced, but unlikely to go down below £200 per annum, so all the improvements must if I consider at around 90 years old likely will need to move out, and 70 now, must be under £3000.
An improvement to make it more comfortable yes can exceed that limit, or when some thing fails, but when one makes an error, as I did fitting Nest Gen 3, then the cost to correct becomes a problem, I was told Nest Gen 3 linked to my Energenie MiHome TRV heads, and it doesn't, Nest removed support when it became Google.
The same with any other so called improvement, when we had the Winter of discontent, those will open fires were OK, they worked fine, but my hot air central heating even when main heat source was gas, did not work with no electric, I had a gas fire installed as a result, I well remember the late 70's, the whole idea of a home that relies on electric seems mad, last house had large gas fire, this house a wood burning fire, with EV charging and electric heating we must expect the failure of electric supplies in the future.
We have people complaining can't get children to school, or can't get to work due to fuel shortages, back in the 70's we walked to school and work, or at least could use a bike. In spite of problems with Colvid and large schools, it seems local authorities have not learnt, and still want larger and fewer schools, blinkers comes to mind.
