Rehan Saeed Posted January 5, 2023 Share Posted January 5, 2023 (edited) I'm trying to choose between two plumbers. One who is a HeatGeek, wants to use Nu Heat, with Lo Pro Lite for the ground floor and DPJ14 – 14mm Fastflo for the first and second floors. Nu Heat have quoted around 10.5k. The other plumber wants to use Wunda with Wundatherm for the ground floor and Between Joist Panels for the first and second floors. I'm waiting for them to send me a quote but sounds like they're much cheaper based on my reading. Both companies also do a metal plate system which goes under floorboards. Nu Heat calls it ClippaPlate and Wunda calls it Spreader Plates. That is another option that has been offered to me but my understanding is that these plates can bow over time and lose contact with the surface we want to heat. Is this correct? The Nu Heat sales person says they use metal plates instead of Wunda's aluminium foil which has better heat output. This makes sense to me. As I'd like to consider a heat pump in future, is this true and will it make a difference? I've tried to compare heat output numbers in W/m^2 but I can't find a match. Apart from this difference, both systems seem functionally the same. Edited January 5, 2023 by Rehan Saeed Link to comment Share on other sites More sharing options...
JohnMo Posted January 5, 2023 Share Posted January 5, 2023 £10.5k - I now see why I did it myself. If you are thinking heat pump in the future, why not think about it now, the government will pay for the heat pump, new cylinder and possibly some of the UFH? Your UFH will be much of a sameness for gas, oil or HP. W/m2 is just a matter of flow temp and spacing. You should be aiming to get low flow temps what ever route you go. Biggest thing to consider is insulation below the UFH loops, without it keep the the money in you pocket. Link to comment Share on other sites More sharing options...
Rehan Saeed Posted January 5, 2023 Author Share Posted January 5, 2023 (edited) Quote If you are thinking heat pump in the future, why not think about it now, the government will pay for the heat pump, new cylinder and possibly some of the UFH? The government won't pay for all of it and I can't afford it right now. I do plan on asking my plumber to setup the pipes for it so I have the option going forward. Quote W/m2 is just a matter of flow temp and spacing. You should be aiming to get low flow temps what ever route you go. Yes, thats my aim. I've watched enough HeatGeek YouTube video's to know some basics. From what I understand though, the higher the heat output of the UFH, the lower the flow temperatures I can use? Hence my question about the aluminium vs metal heat spreaders on either systems. Am I right? Quote Biggest thing to consider is insulation below the UFH loops, without it keep the the money in you pocket. I'm putting in NyRock Rockwool on the 1st and 2nd floors and 75mm of Kingspan Kooltherm k103 on the ground floor, where I have suspended floors. I am considering putting in SuperFoil on top of the concrete areas but this will cause a height difference between the concrete and suspended timber floor. Thoughts on that last part? Edited January 5, 2023 by Rehan Saeed Link to comment Share on other sites More sharing options...
PeterW Posted January 5, 2023 Share Posted January 5, 2023 1 hour ago, Rehan Saeed said: I am considering putting in SuperFoil on top of the concrete areas but this will cause a height difference between the concrete and suspended timber floor. Thoughts on that last part? It will add zero value as it needs airspace to work and even then is poor. Do not do it. 4 hours ago, Rehan Saeed said: Nu Heat have quoted around 10.5k. Is that installed ..?? If not … it’s nuts !! Link to comment Share on other sites More sharing options...
Rehan Saeed Posted January 5, 2023 Author Share Posted January 5, 2023 Quote It will add zero value as it needs airspace to work and even then is poor. Do not do it. They do a product specifically for this purpose called SFUF. Would you still not recommend it? Quote Is that installed ..?? If not … it’s nuts !! Its a pretty large space to be heated over three floors but yes it did seem a lot to me too. Hoping Wunda do better. Link to comment Share on other sites More sharing options...
Thorfun Posted January 5, 2023 Share Posted January 5, 2023 (edited) I had a quote from one guy who wanted to use NuHeat. was stupidly expensive. I ended up buying the stuff direct from Wunda and doing it myself. Also, is your place a new build or renovation? what are the insulation and airtight levels like? most folk on here who have well insulated and airtight houses don't have any heating on the upper floor and they say they don't need it. are you sure you need UFH on all 3 floors? depending on the layout and insulation/airtight levels it's generally thought that electric UFH in the bathrooms is enough to heat the upstairs. might save you enough to be able to afford the ASHP here's our blog post for our attempt at laying UFH. Edited January 5, 2023 by Thorfun added blog link 4 Link to comment Share on other sites More sharing options...
JohnMo Posted January 5, 2023 Share Posted January 5, 2023 SFUF Will give you a u value of 0.8. so units then become, w/m2k. So if you are flowing 40 degree water. And under floor ground is 6 degrees. You are loosing downward 0.8x(40-6)=27W per m2. Say your ground floor is 50m2, that 1.3kW or nearly 900kWh per month. Or £90 a month plus the cost of heating the rooms. Well insulated floor would be loosing way less, my floor has a u value of 0.09, but my typical flow temp is 28. 0.09x (28-6) =2W per m2. 100W per 50m2., 66kWh month or £7 per month Someone will correct if I've messed up the calc. Poor insulation under UFH heating is a big running cost. Link to comment Share on other sites More sharing options...
PeterW Posted January 5, 2023 Share Posted January 5, 2023 1 hour ago, Rehan Saeed said: They do a product specifically for this purpose called SFUF. Would you still not recommend it? Its rubbish !! Radiant foil insulation needs airspace and this doesn’t have any barring the tiny amounts of foam between the layers. 6 hours ago, Rehan Saeed said: The Nu Heat sales person says they use metal plates instead of Wunda's aluminium foil which has better heat output. This makes sense to me. As I'd like to consider a heat pump in future, is this true and will it make a difference? Thats horse$hit too as they both use aluminum spreader plates - the Wunda foil version is the top surface of their overlay system. Both work the same way and need fibre insulation up behind them to keep the plates against the floor surface. Also worth considering what the floor finish will be as that affects heat output / spacing etc. If not going ASHP you will need a buffer tank and you will need blenders and pumps on all manifolds. Link to comment Share on other sites More sharing options...
Rehan Saeed Posted January 6, 2023 Author Share Posted January 6, 2023 15 hours ago, PeterW said: Its rubbish !! Radiant foil insulation needs airspace and this doesn’t have any barring the tiny amounts of foam between the layers. This is good to know. Any good resources I can read about SFUF or foil insulation in general? 15 hours ago, PeterW said: Thats horse$hit too as they both use aluminum spreader plates - the Wunda foil version is the top surface of their overlay system. Both work the same way and need fibre insulation up behind them to keep the plates against the floor surface. The Wunda system uses a very thin layer but it covers the whole board, while NuHeat seem to use a thicker aluminium plate but it doesn't cover the whole surface. I was not sure if this matters but Nu Heat seem to think so. I plan to have all floors insulated as mentioned above, so no problem there. Quote Also worth considering what the floor finish will be as that affects heat output / spacing etc. Planning on a QuickStep laminate flooring with an underlay (not sure which one yet, any recommendations?). Quote If not going ASHP you will need a buffer tank and you will need blenders and pumps on all manifolds. I would like to but can't afford it just yet. Ideally, my pipes to the external unit would go through the kitchen to the back garden. I could route them around the kitchen by going outside the side of the house but I'm told that is not ideal and I'd be losing some efficiency to having a longer pipe and also having it external to the property. Link to comment Share on other sites More sharing options...
ADLIan Posted January 6, 2023 Share Posted January 6, 2023 'SFUF' has a core thermal resistance of 0.8 m2K/W. This is equivalent to approx 18mm of polyurethane foam board - I'm sure we'll all agree totally inadequate for a heated floor. Link to comment Share on other sites More sharing options...
Rehan Saeed Posted January 6, 2023 Author Share Posted January 6, 2023 15 minutes ago, ADLIan said: 'SFUF' has a core thermal resistance of 0.8 m2K/W. This is equivalent to approx 18mm of polyurethane foam board - I'm sure we'll all agree totally inadequate for a heated floor. Good to know. But surely it is still worth using on a concrete floor where you'd otherwise use no insulation? Link to comment Share on other sites More sharing options...
richo106 Posted January 6, 2023 Share Posted January 6, 2023 I am also having this dilemma at the minute on what to install on my first floor. Ground floor is in the 50mm screed above 200mm PIR First floor - solution I am thinking of going for at the minute is profix panels from UK underfloor heating https://www.ukunderfloorheating.co.uk/product/profix-panels/ I will be fixing this directly to my first floor 22mm T&G floorboards and then it will have a thin layer of screed all over. This was suggested to me so the heat wouldn't have to transfer through the floorboards first....especially as we are having ASHP Link to comment Share on other sites More sharing options...
JohnMo Posted January 6, 2023 Share Posted January 6, 2023 Not sure how they have worked out the R value (0.8) either, as at 6mm thickness that the equivalent to a vacuum insulation, which it isn't. Link to comment Share on other sites More sharing options...
Mattg4321 Posted January 6, 2023 Share Posted January 6, 2023 (edited) Everyone on here says forget ufh without insulation, yet NuHeat claim only between 6-10% heat loss downward on uninsulated solid floor. This doesn’t sound too bad at all to me with no insulation. Who is correct?! http://files.nu-heat.co.uk/core/media/media.nl?id=4282445&c=472052&h=4b56e596b2e2e2df1d82&_xt=.pdf&_ga=2.69858192.1819237486.1540816311-991974963.1518786863 page 4 Edited January 6, 2023 by Mattg4321 Link to comment Share on other sites More sharing options...
JohnMo Posted January 6, 2023 Share Posted January 6, 2023 The install manual does contradict it's self all over the place. Stating you do and don't need insulation. You need to be careful with such statements as "Due to the thermal characteristics of a solid sub-floor downward heat loss is limited to between 6% and 10% of the total heat output, which represents a small percentage of the annual heating costs for the property." So does these actually mean, you are already loads of energy in to your floor, what does an extra 6 to 10% matter? Interesting in the solid floor part, it states "which include being able to run the heating approximately 1˚C lower than with traditional radiators and low flow temperatures that mean condensing boilers operate more efficiently". So you can run the UFH at 69 degC? Interesting my UFH at -2 the other week ran at 30 degC, 40 degC lower than traditional radiators! That does make the boiler run efficiently. Do you own maths. Make sure you are comfortable with your choice. So if you happy to increase your energy consumption from heating by 10% over the cost of radiators, fill you very warm boots, because your floor could be very warm. 1 Link to comment Share on other sites More sharing options...
Seren161 Posted January 6, 2023 Share Posted January 6, 2023 On 05/01/2023 at 17:58, Thorfun said: Also, is your place a new build or renovation? what are the insulation and airtight levels like? most folk on here who have well insulated and airtight houses don't have any heating on the upper floor and they say they don't need it. are you sure you need UFH on all 3 floors? That’s what we have found..We have UFH on all 3 levels with a govt “subsidised “ ASHP but we have found that turning on one level on is plenty warm enough.. Might be worth saving on the upper level and putting the savings to the heat pump. Link to comment Share on other sites More sharing options...
PeterW Posted January 6, 2023 Share Posted January 6, 2023 1 hour ago, Mattg4321 said: Who is correct?! Not NuHeat..!! As the standard heat loss calculation will show ..!! Link to comment Share on other sites More sharing options...
tuftythesquirrel Posted January 8, 2023 Share Posted January 8, 2023 On 05/01/2023 at 15:53, PeterW said: Is that installed ..?? If not … it’s nuts !! @PeterW @Rehan Saeed We had a quote from NuHeat for 250m2 UFH in screed, NuHeat were £8k for parts. Went with the Underfloor Shop, all Emmeti parts were just under £3k plus excellent service. John Guest were even sillier at £11k. Link to comment Share on other sites More sharing options...
jayc89 Posted January 8, 2023 Share Posted January 8, 2023 I spec'd mine myself; 70m2, 150mm centres, Heatmiser UH8 Wiring Centre, 4x NeoStats v2, Grundfos pump + ancillaries (actuators, staples, eurocone's etc) £1200 from Underfloor Heating Direct. If I was to do it again, I wouldn't have so many zones and therefore stats, and I'd probably go with Salus Auto Balancing Actuators to better compliment the variable flow temp caused by the boiler's weather comp. Link to comment Share on other sites More sharing options...
Jilly Posted January 8, 2023 Share Posted January 8, 2023 Nu-Heat were about double the cost of Wunda last time. Link to comment Share on other sites More sharing options...
Nickfromwales Posted January 9, 2023 Share Posted January 9, 2023 NuHeat = 💩. Link to comment Share on other sites More sharing options...
Nickfromwales Posted January 9, 2023 Share Posted January 9, 2023 On 06/01/2023 at 20:50, Mattg4321 said: Who is correct?! Seriously? Link to comment Share on other sites More sharing options...
Nickfromwales Posted January 9, 2023 Share Posted January 9, 2023 On 06/01/2023 at 10:26, Rehan Saeed said: Any good resources I can read about SFUF or foil insulation in general? Search "multi foil" here Link to comment Share on other sites More sharing options...
Mattg4321 Posted January 9, 2023 Share Posted January 9, 2023 1 hour ago, Nickfromwales said: Seriously? Playing devils advocate, how would NuHeat attempt to justify their claim that such a small heat loss goes through an uninsulated solid floor? Link to comment Share on other sites More sharing options...
PeterW Posted January 9, 2023 Share Posted January 9, 2023 8 minutes ago, Mattg4321 said: Playing devils advocate, how would NuHeat attempt to justify their claim that such a small heat loss goes through an uninsulated solid floor? Because most people don’t understand heat loss to be frank. 10% of the heat loss of a system is a lot - and when you look at energy prices and that is £250 a year which should be £50… it soon adds up. I also don’t think it’s 10%, and is substantially more but not knowing the rest of the building make up you can’t guesstimate it Link to comment Share on other sites More sharing options...
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