Tim, if you won the lottery and decided to build a new home, what kind of system would you go for with hindsight?
UFH, radiators, ducted air or what? I hope you don’t mind all these questions.
rgds,
Martin
New builds tend to go with UFH, which usually means lower flow temperatures and higher efficiencies. This is the obvious choice.
Retrofit installs typically rely on fitting newer radiators, which is what I did - works well enough.
Ducted air is fairly uncommon here in the UK, but other countries do have them. The alternative is to have multiple small air-to-air heat pumps, on either side of an external wall. This can work well in some situations, but probably not the first choice for a new build.
(just my opinions, I’m no expert)
Compared to me, you are an expert! But which system would YOU choose?
For a new build, underfloor heating, for sure.
I don’t know the merits of having UFH in upstairs rooms, or if they’d be better off with radiators. 
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Hello,
Following the dialogue regarding UFH. I am just about in install as ASHP. But my property was built in 09 and has UFH fitted on the ground and first floor, which are both concrete floors. The top floor is timber construction.
My overall experiences over 12 years are as follows.
- UFH on concrete floors with ceramic, marble tiles etc works well.
- UFH on concrete floors with an engineered wood floor bonded to the concrete floor, also works reasonably well, but obviously not as good as ceramic.
- I have one UFH zone on the top floor where the pipes are installed underneath a chipboard floor which is then covered with ceramic tiles. The performance is poor and this is using a higher flow temperature than would be used using an ASHP. I wouldn’t install again and please note it was installed using Polypipe’s procedure and the area under the floor is very well insulated.
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I think I would go for radiators or ducted air as these would warm a room more quickly. I would look for a cascade system with heat pumps in series as it can get very cold where I live. I will be looking at Scandinavian suppliers as they have lots of experience. I’m not in the market for a heat pump yet.
A good option if it overall works with the rest of the heating system and the property layout. Look at installing individual air to air units. They work exceptionally well and are very efficient, my experience is large spaces where the complement UFH
In a New Build (I’ve done 2 self-builds), assuming downstairs living, upstairs bedrooms, UFH under tiles downstairs and ducted air upstairs. I’d build a cube with large open plan downstairs and one small corridor from front door.
To me warm tiles are the best and they feel cool in summer. so UFH and large tiles; easy to maintain. Only put it in main areas (not halls, cloakrooms etc).
Upstairs ducted air, probably 2 units or switchable ducts as 2/3 rooms not used.
Flat sedum roof, HP units on roof (with Solar).
A smaller unit for the (large) Garage UFH 
(it will be fully insulated!).
Not that I’ve thought about it… Just need the land 
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When I win the Lottery, I will build a circular house that revolves. It will have a vast spiral staircase or ramp with the rooms between this and the glass walls. the central are will be the living, cooking and dining space. There will be a wood burner suspended from a central flue with 360 degree visibility.
GSHP will feed UFH and radiators. Or a nice cave house in Spain as I don’t like the heat.
Another consideration is air source vs. ground source. If you’re building a new house, and the garden is a building site anyway, then there’s little disruption to adding ground loops / bore holes.
On the other hand, modern air source heat pumps have gotten much better, and may be performing as well as ground source now. (I don’t know for sure, but worth looking into maybe).
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Better to ask what insulation system would you choose - if you go PassivHaus then you wouldn’t necessarily need a heating system.
We’ve just moved into our self build which is a highly insulated timber frame, almost PassivHaus spec and almost airtight. The house is in 2 sections, a large vaulted 1 storey kitchen/dining/living room and a 2 storey section with a snug and bedroom on the ground floor and 2 bedrooms on the 1st floor.
The whole ground floor is an insulated slab with the UFH pipes built in. There isn’t any heating on the 1st floor and that works fine. Due to the high level of insulation and the MVHR unit which brings in fresh air heated by recovering the heat from the exhaust air, the whole house is an almost constant temperature.
There is a lot of advice about insulation, heating options etc. on the BuildHub forum → All Activity - BuildHub.org.uk. One of the original team who built his own house created a heat loss spreadsheet which is very helpful to work out how much heat you’ll need given the various levels of insulation (roof, walls, floor etc.). Once you know how much heat you’ll need, you’ll have a better handle on whether a type of system would work and how big it might need to be (max output).
As with everything though there’s a devil in the detail. Each person in the house adds quite a chunk of heat, so at Xmas with the family around, with the oven on, we had a rooflight open to cool things down, even though it was pretty cold outside. The spreadsheet above doesn’t take any account of people, or the heat from cooking. And today with the amount of sunshine, the heating won’t turn on - we’ve a lot of south facing glass - this was intentional and it’s all under overhangs, so we don’t overheat in the summer.
We installed a small ASHP on the government BUS. The grant paid for the heat pump and installation which was nice. When it’s needed this runs for 4 hours on the Octopus Go 7p tariff, although when it’s been really cold, we’ve supplemented this a few hours in the afternoon.
For us, like @borpin, UFH is great, as the tiles are warm in the winter and cool in the summer. You wouldn’t get that with ducted air. And of course there aren’t any radiators getting in the way of your furniture.
@kelper, if the house is highly insulated, then the temperature doesn’t vary much, so speed isn’t an issue. Long and slow does the job.
At the start of our planning, we looked at ground source vs air source and GS was anything upwards of at least £5k more than air source. We looked at it because we have the land but it was a no go from the start. I think the units are pretty comparable with the exception that GS doesn’t have to stop to defrost when the weather is cold - although it does cool the ground which isn’t apparently very good for some plants.
Simon
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If you build a passive house, you do not need heating…
Depends on how warm you like your house! I also think this is a myth for a detached dwelling. A block of flats with fewer external walls, perhaps.
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You do, just not much. Trouble is the smallest ASHPs are generally too big, which means they are difficult to run at high efficiency. We have a 190m2 PH+ with 3kW ASHP for a maximum heat load of 1500w @ -3C.
Three people in-house = no heating, two people = heating on!
Having house living space upstairs has worked really well, with warmer upstairs in winter and cooler bedrooms in the recent 40C summer.
We have skirting board radiators (Thermaskirt) which distribute heat better than radiators and don’t require ufh in wooden fabric. They suffer from expansion/contraction noise when the DHW cycle dumps the high flow temp back into the heating circuit as it finishes (no buffer). Worth considering as a solution for low flow temp systems, but cover the noise issues at design stage. Happy to contribute honest views if anyone is interested!
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