Should I get underfloor heating?

Bendy_House

Good points, CG.

Chickereeeee

With the surface mount UFH systems, "where a profilled insulated panel is installed on top of an existing floor", do you actually NEED to install insulation under a wood floor? The panel itself is good insulation, albeit thin, and the floorboards beneath add another layer. Granted the more insulation the better, but does adding more justify the cost and disruption? Heat rises (by convection anyway) so naturally more heat would be transferred upwards.

ComicGeek

Chickereeeee said:

With the surface mount UFH systems, "where a profilled insulated panel is installed on top of an existing floor", do you actually NEED to install insulation under a wood floor? The panel itself is good insulation, albeit thin, and the floorboards beneath add another layer. Granted the more insulation the better, but does adding more justify the cost and disruption? Heat rises (by convection anyway) so naturally more heat would be transferred upwards.

If the profilled panel is insulated, and the joints taped etc to prevent air leakage, then no you don't have to install insulation under the wood floor. Even a small amount of insulation in the panelbelow will mean that the heat conducts mainly up through the floor finish and then heats the room by a mixture of radiation and convection. Still worth sealing up air paths first though.

The good thing about the profilled panels is that the heat is produced into the room much more quickly.

The bad thing about the profilled panels is that the maximum heat output is lower than the screeded option as the heat from the pipework is more efficiently distributed to the floor finish - with all UFH systems you have to make sure that the floor finish doesn't get too hot, so that it doesn't crack/distort or be too hot for people's feet. The screeded option has the benefit of the heat spreading throughout the mass of screed, so the water temperature can be higher and the pipes closer together and the overall heat output is higher. However, the screed is also an inefficient part of the system, and the correct answer is always to insulate, insulate, insulate until you only need a small heat output - at that point you can run the more responsive system at a lower water temperature and reduce energy usage even further.

anon_ymous

Bendy_House said:

waqasahmed said:

Would it be worth putting in UHF if say I'm putting in insulation for solid floors? And in that regard, I'm guessing wet is better than dry? 

ASHP are going to tumble in price, almost certainly (Octopus is on the case...), and almost certainly their effectiveness/efficiency will also be increased (eg talk of CO2 as the refrigerant).

That's fair. I'm waiting for ASHP to either match the price of boilers, or have a higher COP than 4. Assuming the Ukraine conflict comes to an end, we'll hopefully be back at pre crisis levels in terms of energy costs, but we can't exactly rely on gas, given likely further escalations by the big three imperial powers, and given that it is going to "run out" eventually. 

Bendy_House said:

Get quotes for both systems, Waq; wet UFH and oversized rads, and make your decision?


Please remember two things, tho'; one INSULATE EXT WALLS (on their insides, ideally) and floors, and two, fit OVERSIZED rads, choosing locations that simply fit in and look best. On our new extension, I fitted a tall column rad to each beam support pillar, and I actually like the look; rads don't have to be an eyesore.

Thanks. FWIW, the house I'm buying is already very well insulated, but I was looking at external insulation. I figure that I should get as much insulation as is economically feasible, doesn't intrude much on the rooms, and installed properly , so it doesn't cause damp

ComicGeek said:

Personally I would never get UFH myself unless I had a very well insulated and air tight house with exposed thermal mass internally and very good external shading on any glazing areas. You will struggle to find many of those in the UK.

Perhaps I don't quite have an air tight house, or very good external shading on any glazing areas. I am tbf, looking at two other solar companies for solar PV. One is polysolar, which appears to be the only solar company that sells solar windows with decent efficiency , and Solar gaps, which is the only company that provides solar blinds. The nice thing there too, is that they're smart, so they help reduce AC usage, which isn't a particularly big concern atm, but AC is becoming an issue in the UK, which then in turn makes the planet even warmer which is less than ideal. 

FreeBear

waqasahmed said: I'm waiting for ASHP to either match the price of boilers, or have a higher COP than 4.

From what I've seen of ASHP, a COP of between 2 & 2.5 is about the best you can hope for in the depths of winter. You might get up to 4 with GSHP, but the installation costs is much higher.

If I had the cash and suitable access to my rear garden for a big rig, I'd be drilling boreholes and installing a GSHP. As it is, I can only get something like a Dando Terrier in which limits me to a borehole depth of around 40m.

anon_ymous

FreeBear said:

waqasahmed said: I'm waiting for ASHP to either match the price of boilers, or have a higher COP than 4.

From what I've seen of ASHP, a COP of between 2 & 2.5 is about the best you can hope for in the depths of winter. You might get up to 4 with GSHP, but the installation costs is much higher.

If I had the cash and suitable access to my rear garden for a big rig, I'd be drilling boreholes and installing a GSHP. As it is, I can only get something like a Dando Terrier in which limits me to a borehole depth of around 40m.

From what I've seen, apparently the biggy is the installer, and their knowledge, and how they design the system. Apparently heat geek installers average around 3.5 to 4 which at least puts us on parity with gas usage.

Still, either way, I imagine more people would put them in, if they become more efficient. We should hopefully be out of pre crisis as of maybe four years, but in that time period, gas won't meet parity with electricity bills especially given that 25-50% of our electricity is produced using gas. I then can't also see people installing these even with an average of COP of 2+ , at least in the medium term 

By 2025, I think we're meant to use more nuclear however 

DRP

waqasahmed said:

FreeBear said:

waqasahmed said: I'm waiting for ASHP to either match the price of boilers, or have a higher COP than 4.

From what I've seen of ASHP, a COP of between 2 & 2.5 is about the best you can hope for in the depths of winter. You might get up to 4 with GSHP, but the installation costs is much higher.

If I had the cash and suitable access to my rear garden for a big rig, I'd be drilling boreholes and installing a GSHP. As it is, I can only get something like a Dando Terrier in which limits me to a borehole depth of around 40m.

From what I've seen, apparently the biggy is the installer, and their knowledge, and how they design the system. Apparently heat geek installers average around 3.5 to 4 which at least puts us on parity with gas usage.

Still, either way, I imagine more people would put them in, if they become more efficient. We should hopefully be out of pre crisis as of maybe four years, but in that time period, gas won't meet parity with electricity bills especially given that 25-50% of our electricity is produced using gas. I then can't also see people installing these even with an average of COP of 2+ , at least in the medium term 

By 2025, I think we're meant to use more nuclear however 

Is there any nuclear due to come  online by 2025? Hinckley point C is currently 2027. 

Exodi

I have wet UFH throughout downstairs and radiators upstairs so to give my perspective on things -

1) Time - it takes significantly longer to 'feel' the heat from UFH compared to radiators - as the heat has to heat and travel through a solid materials, compared to just travelling through the air like a radiator. This means if I'm cold, I can switch on a radiator and feel the warmth from it in a couple of minutes, UFH on the otherhand may take a couple of hours. On the flipside, after switching off the radiators, the heat will soon start decreasing, whereas UFH may stay hot for hours after they are switched off. For this reason, UFH is best combined with thermostats and routines - they are not great if you're reactive (e.g. 'it's cold this evening, I'll put the heating on' - all this will do is keep the house warm during the night).

2) Spread - while the hottest point of a room with a radiator in is obviously around the radiator, with UFH the heat is even spread across the floor making the whole room an even temperature.

While I do think UFH is superior, I wouldn't consider retroactively installing UFH.

anon_ymous

DRP said:

waqasahmed said:

FreeBear said:

waqasahmed said: I'm waiting for ASHP to either match the price of boilers, or have a higher COP than 4.

From what I've seen of ASHP, a COP of between 2 & 2.5 is about the best you can hope for in the depths of winter. You might get up to 4 with GSHP, but the installation costs is much higher.

If I had the cash and suitable access to my rear garden for a big rig, I'd be drilling boreholes and installing a GSHP. As it is, I can only get something like a Dando Terrier in which limits me to a borehole depth of around 40m.

From what I've seen, apparently the biggy is the installer, and their knowledge, and how they design the system. Apparently heat geek installers average around 3.5 to 4 which at least puts us on parity with gas usage.

Still, either way, I imagine more people would put them in, if they become more efficient. We should hopefully be out of pre crisis as of maybe four years, but in that time period, gas won't meet parity with electricity bills especially given that 25-50% of our electricity is produced using gas. I then can't also see people installing these even with an average of COP of 2+ , at least in the medium term 

By 2025, I think we're meant to use more nuclear however 

Is there any nuclear due to come  online by 2025? Hinckley point C is currently 2027. 

Fair. I thought 2025, but I stand corrected. Either way, for the medium term, gas likely won't achieve parity if gas is about 25-50% of electricity production, until that point. (Or if government intervention happens outside of market forces) 

Bendy_House

DRP said:

Is there any nuclear due to come  online by 2025? Hinckley point C is currently 2027. 

I understand they are hoping to extend the service life of Nukes which were due to be decommissioned.