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  1. Hello We have built a large extension to an early 1900’s house to be heated by ASHP with buffer tank. We are installing a wet UFH system using 3 manifolds due to the position of the zones. We will also have radiators in the bedrooms in the old part of the house. Looking at various heating system designs online, I am confused as to what valves I need to install and where in the pipework. Do I need a zone valve for the radiator circuit and one for the UFH circuit? Or do I need a valve for each manifold? And should the valves be located at the buffer or at the manifolds? I have also seen some circuit drawings with non-return valves on the return legs of the UFH, presumably to stop the other circuits trying to push the wrong way. Any advice greatly appreciated.
  2. Hi My first post here - was pointed in this direction by a friend of mine. After months of research (feels like months) I think I have come to a conclusion on which UFH system and I just needed some support on ensuring I had made a right decision (otherwise my wife and kids will kill me in the middle of winter). Background I am doing a renovation project of the ground floor of my house - 95m2. It is a 1930s semi - whole place is being gutted and an extension going in. The current flooring is timber joists and in a bad condition and has no insulation. So first job will be to rip up the flooring and add 100mm of Kingspan or Celotex in between the joists. Now the complexity of which UFH system to go for. I have boiled down to 2 options: Option1: TorFloor by Omnie - I can use these boards as the structural floor, I am hoping a competent plumber can install this and I can get a 9mm plyboard on top and finish the floor with LVT like Karndean. The height build up is 35mm (22m board, 9mm ply, 4mm Karndean). So the build up is pretty similar to what I have with the existing boards and underlay and carpet Option2: Install a pannelling and screed system (like Nuheat or Profix). With this system I would put some 6mm T&G plywood over the top of the joists, put down the castellanated panels, pipes would go in and screed on top. As I cant put Karndean straight on top of the screed, i would need to finish with 6mm ply and Karndean finish on top. So the build up is 80-85mm (6mm ply, 15-20mm panels depending on system, 50mm screed, 6mm ply, 4mm karndean). It is not clear how much screed I need as some systems are different. I am hoping I have described the above scenarios correctly - I am not a seasoned DIYer so all the research has been mind blowing !!!. In conclusion I am tending to go for the Omnie Torfloor system - number of reasons - floor build up is lower and its £3k cheaper. However what I dont know is the output and difference between a screed system and an overlay system. Any opinions on my conclusions?? Please tell me if I have got this one wrong !! Ideally I need a fairly quick heat up and a fairly good output - kids and mrs moan in the middle of summer of how cold it is !!! Thanks for reading
  3. Although planning a building on the East coast in the highlands, I do have a concern for over heating. Heating to be thermal store - ASHP - PV and ( possible Solar thermal)- all DIY, possibly a small wind turbine connected to DC immersion - it is windy all the time....... Anyway I got to thinking about cooling, and read some people use the ASHP and buffer tank to cool the UFH. I plan to have 6000L rainwater tank ( it also rains a bit), this tank will be underground and relatively cold, so I thought a couple of three port valves and a dedicated loop of pipe running through the tank would provide all the cooling needed and a possible heat dump for the solar. Any thoughts , problems you see.
  4. Hi All, I hope you're keeping well! I just wanted to introduce myself 'Joe' to the forum as I have been a long time reader and now hopefully getting closer to starting my own build. The forum is such a great resource for information and the knowledge of the users is simply amazing - I really do appreciate everything I have read here as it has helped me so far on my journey. I am hoping to learn as I go and all being well, I'll be able to help others as I pass through each stage of the build and gain my own knowledge and experiences. The house is a two story house with a connection to single story building for the kitchen, dinning and living area which in total is approx 330m2 sitting on 0.8 of an acre. It will have a ground source heat pump, with underfloor heating on the ground and first floor, mechanical ventilation heat recovery system and a PV solar array with battery. Windows triple glazed throughout. The current SAP report SAP rating: 92 A Environmental: 93 A If I have missed anything I will update the above. All the best, Joe
  5. Converting a 3 bed very dilapidated 1930s semi into a 4.5 bed modern home. EVERYTHING is being gutted except the joists. Quotes are way over budget, particularly for the underfloor heating. I had specified wet underfloor heating throughout all three floors of the house (ground = 800 sqft, first = 750 sq ft and loft = 450 sqft), with the ground being imbedded into screed and the first and second floors being laid within some high performance extruded polystyrene boards made by Cellecta called XFLO. XFLO is quite expensive, about £26 a square metre, but the reason I had specified them is that they provide good insulation to make sure the heat goes up, are CNC drilled by Cellecta to meet any pipe layout requirements we specify and also feel quite firm underfoot. The other advantage of the XFLO is that you can lay the finished floor directly onto it. Underneath those XFLO boards, I had specified a 6mm dense rubber matting (which comes as a 10m by 1m rolled product, so pretty easy and quick to lay) to absorb impact sound, and underneath that 18mm tongue and groove ply which is nailed directly onto the joists (whereas the rubber and XFLO are just floating). In between the joists I was going to have mineral wool to mute airborne sound travel, and underneath the joists I was going to have the ceiling attached using resilient bars (with market name "Genie clips") to isolate the ceiling from the joists to further prevent sound transmission. The whole system is to be zoned as 9 zones, including one zone for the 3 towel radiators (which will be the only radiators in the house, one for each bathroom), although I'm going to provide Tado thermostats, one for each of the 8 UFH zones and a Tado smart valve for each of the towel radiators. One builder has quoted about £25k plus VAT for all of the above, and the other about £28k plus VAT. These quotes don't include the thermostats (I'm providing those). When I have challenged each of them on why this is so expensive (I was expecting about half the cost) they have said different things. The first builder has said that I could save £2,500 to £3,000 money by losing UFH in the loft and in most of the first floor, and instead having radiators there. The second builder doesn't agree that would save any money and is also trying to respect our reasons for having UFH. Instead he just thinks the system I've specified for the first and second floor is overkill and that I could make two changes which would save about £4k in labour: First, instead of 18mm ply plus 6mm rubber matting plus the XFLO boards (which are about 28mm thick) I should just lay a product sold by theunderfloorheating store calledProWarm ProFloor 22mm pre-routed chipboard. I've looked this up and I see the benefit. Like the XFLO boards, you attach it directly to the joists and it comes routed (though with standard not bespoke routing) and enables you to fix the finished floor directly. It costs roughly the same as the XLFO, but it saves the builder the trouble of having to lay the rubber matting and the ply, so the saving is in the cost of the matting (£6 per sq metre), the ply (about £14 a sq metre) and the labour to fit those two layers. Second, he says that in the bathrooms, I should just lay electric UFH rather than wet. He accepts it's dearer to run, but he says I can have smart timers on it to make sure I only have it on when needed and as there will be wet towel rails in there, I really won't use it that often. I think I'm willing to accept his second point and fir the electric UFH in the bathrooms, but I'm concerned about the disadvantages of the first point, which I see as follows: 1) I lose the impact sound protection provided by the 6mm rubber - is this such a big deal given I have an isolated ceiling and the mineral wool between the joists? If so, can anyone think of a way of combining a fairly cheap but effective sound impact layer with the 22mm pre-routed chipboard? It would only ever be my kids running around, so impact sound is not a major issue, but I want some protection. 2) Chipboard is not as durable or as strong as ply. Although both will feel similar at the outset of their lifespan, what will they feel like in 12 years time? I plan to be at the property for 12 years at least, but hopefully longer and I don't like springy floors. 3) no bespoke pipe channels like Cellecta offer with XFLO. But is this overkill? Maybe I don't need bespoke pipe layouts. Builder says that the 22mm pre-routed chipboard just has channels at 200mm pipe centres and that is a standard construction for first and second floors. Although most of the rear of the house is being extended, so it will have insulated cavity walls, and the loft will also be well insulated, the rest of the house has no cavity walls. Keen to hear your thoughts on the above. Thanks for your time!!!
  6. A couple of years ago, I bought a house heated by a 14kw Ecodan ASHP with a Mitsubishi pre-plumbed cylinder system, that was installed in 2015. It has zone 1 to heat 10 radiators and zone 2 to heat 3 loop wet UFH for the kitchen and utility - also heats DHW. During the colder winter months and late frosts this year, it was clear that the UFH was failing to heat the kitchen/utility floor. The input to zone 1 is physically higher on the low loss header, so if both zone 1 and zone 2 are on at the same time, zone 1 takes the heat, and no heat travels down the low loss header to zone 2. If just zone 2 is on, some heat goes into the zone 2, but much of it travels down the low loss header to the return. This causes the return to be almost as hot as the flow, so the Melcloud reports show the return temperature tracking the flow temperature. When it reaches the peak temperature, it cuts out and flushes with cold water from zone 1. This shows as a sawtooth effect of fast cycling - the cycling is very regular, every 10 minutes. If zone 1 is on by itself, this does not happen - the return remains lower than the flow and there is no cycling (I've attached a melcloud report showing this). The system has been serviced, I've flushed the UFH loops out (via hose - a small amount of muck came out but not much and the flow was OK) and inserted more biocide. I've tried altering the pump speeds. To reduce any flow obstructions, I've removed the flow meters and used blanking plates. I've replaced the Heatmiser UH2 with a standard Ecodan wireless thermostat, and Salus THB23030 actuators. I still have the 10 minute cycling. I have a feeling that the ASHP is too big for the UFH by itself - but not big enough to heat both zone 1 and zone 2 together. I've tried asking UFH and ASHP installers and maintainers, but they look even more baffled than I do and offer no help (with all the green deal stuff, they are too busy installing new systems to bother with maintaining existing ones). I just wondered if anyone had any thoughts or ideas as to anything I could try? Many thanks Eric
  7. We’ve recently installed UFH in our first floor extension using Nu-Heats spreader plate system. Long story short, the plumber missed the small print which specified that additional heat sources were required in the bathroom to get it up to temperature, so we’re now looking at the best option for plumbing a towel rad. Plumber wants to simply run a new central heating run in and drive the rad off the main hallway central heating stat, however given the bathroom is setup as it’s own zone with stat etc, that seems a massive waste. Is there a way to run the rad and UFH off the same room stat and zone? Is it possible to plumb the rad into the end of the UFH loop?
  8. I'm taken the general recommendation to use Wunda for UFH design and see they offer a neat solution using aluminium spreader plates to fit regular UFH pipes between the joists for first floor bathrooms etc. This avoids need to install pipes on top of the floor and eliminates the level changes that would arrise. Has anybody had experience of using this system? Seems to be a good alternative to electric systems and I'm guessing a lot cheaper to run form the ASHP. One issue i can see is that the spreader plates and UFH pipes would need to be installed before the floor is laid which may be an issue in practice. Any advice welcome.
  9. We have an old concrete slab, and hope to have UFH. The ex builder placed stud walls onto the floor, sitting on DPM (after initially saying they would lay it onto a brick course). If the visible DPM plus another on the floor in each room is lapped up the walls, it will encase the bottom part of the timber wall in plastic. Will that be ok? It seems to me it will get condensation and rot the wood at the bottom? Said builder will never come back to rectify (I have waited 6 months for other bits and given up). Thank you!
  10. Hi, I’ve got a rear extension within 45sqm of floor area which will be new floor (insulated, concrete and liquid screed with ufh). The existing area at rear of house is 25sqm of timber suspended floor. I’ve looked at the void is 750mm deep. Is this too much to make up? So I just leave the existing as suspended and run ufh under floor boards onto insulation between joists then vent it through the new slab or fill it? The other advantage of doing that would be less chance of crack straight across what will be a new porcelain kitchen floor. Thanks in advance
  11. Hi all, I'm going to apologise in advance as I have limited technical knowledge on underfloor heating and general construction. I was hoping to get some advice on our wet underfloor heating installed 3 years ago. Its one system across multiple zones. It works really well in the new extension where we have concrete flooring with a microscreed finish. However in the old part of the house we have a room with a joist flooring and engineered wooden flooring and here the heating is never warming up the room. The floor boards are always cold and a thermometer in the never shows the temperature going up. I checked the in and out pipes on the manifold and all appear warm. I decided to rent a thermal image camera to see if I could spot any problems. All the pipes are appear to be working but the temperature readings are very small 21C compared to the new extension where we get 25C.. See attached photos I am wondering if this is a normal or expected output? We as a family freeze in the winter and never tend to stay in the room long because of the cold. I don't recall how the builder installed the pipes but I do remember some insulation went in first then the pipes and followes by the flooring. I assume this is OK? I'm wondering maybe the heat is getting lost by the fact we have an external solid wall so insulation in the room is clearly not as good as the new extension but I it does not explain why the floor is stone cold. Any advice? Ps I did spot the builder placed the pump in the wrong direction so the out flow is going through the in pipes and therefore the flows which are set to max do not register any flow. I'm having this fixed by a heating plumber so that might give us more control.
  12. Hi there. We're upgrading our sixties house in Sussex with a GSHP, underfloor heating and a new hobby room (separate building) with a goodly chunk of solar PV to go onto its roof. The hobby room will have a separate ASHP. The insulation in the house has also been improved. We've done most things in the house but the new hobby room is yet to be built (we have planning permission) and we're just at the stage of re-wiring the existing house. Octopus have installed a three phase smart meter, although we only have two phases to the house (and that ain't gonna change). Stumbled across this site and wonderful forum when searching for how the importing and exporting of power is going to work with two phases, potentially phases both generating and using power. Any experience or knowledge in that area gratefully received! Cheers UncleK
  13. Morning everyone Our house build is progressing nicely and we have recently had the ufh installed both downstairs in the traditional way (stapled to insulation, screed on top) and also on the first floor, in 25mm in between batons etc. We then screwed and glued 6mm ply to the batons to protect the screed and provide a sound surface for tiling/flooring. Although the dry screed was swept and hoovered before the ply was laid The problem we are now finding is a 'crunching' noise when you walk around, between the ply and the screed. Has anyone who has used this system experienced similar problems? Does it go in time? I don't want to get to a position of getting carpets etc down and still hearing the annoying crunch. Any advice/experience gratefully received. Many thanks
  14. Right, so following on from my blog entry here where I discuss using Willis heaters to heat up my UFH ( ) I'd initially tested them earlier in the year when I'd set them up and then only in the past 4wks really started to use them for some evening heat in the house and they did their job pretty well (not turned on all the loops yet as there are some rooms that aren't completed yet (north colder part of house). So only switched them on manually for say 2-3 hours each day. Yesterday one of the heaters started 'making noises' that he was not happy, so I switched that one off and left the other one to run. Then today the other one also decided it was not happy. Video below, with aforementioned Willis...'making noises'. 20201112_164008_001.mp4 To me it sounds like a kettle that's trying to boil/simmer with not enough water. I'm suspecting it's scaled up already in this short time. There's no heat coming from the outlet pipes at all and the heaters themselves don't feel warm either. I still have pressure (1.5 bar) so I don't think I have a leak anywhere and no water in pipes. The manual bleed valves indicate there's water in the manifold at least. Any other ideas before I start dismantling the buggers as there's at least 4 compressions I have to bugger about with which were a pain to seal initially? Resident willis heater experts @Nickfromwales, @TerryE ? :-) TIA!
  15. Hi community, Over the last 2 weeks I've been trying to take in lots of info regarding ashp since having one installed in a new build, thanks so much to all the people that contribute with their esteemed knowledge, much of it on here is well above my basic understanding and it seems there are a myriad of things to consider when trying to optimise the systems. Bit of background, 186m2 timber frame kit from a company called scotframe, as a non builder this seemed like a means of eradicating some of the problems with builders as it progressed. Product has been good aside the nordan windows and doors imo, the erectors not so good, wish I'd hired a chippy with lots of new build experience to keep and eye on them but I am where I am now.. if anyone has questions about scotframe always happy to share my thoughts and experiences. Installed I have an ecodan 8.5kw system with ufh downstairs dfor heating and DHW. no buffer tank just the ecodan cylinder with 6 room stats downstairs. Vent axia sentinel mvhr yet to be commissioned / balanced. 75mm screed on top of 140mm celotex. pipe spacings at 125mm (mostly anyway). Been running now for 2 weeks, the house is at a comfortable temp downstairs, 17 deg, and that what's the stats are set at, not lived in yet but in this cold weather seems heating will be needed upstairs with points for electric heaters of some sort ready for the future. After lots of reading on here I've decide to run the ufh at a low flow temp, presently 29 degrees and run it continuously aside from peak pricing times with octopus agile.. . The house seems to hold heat reasonably well but until I move in to a semi building site in around 6 weeks I wont know exactly how it performs. Whilst the heat pump installer / plumber was a lovely chap and had a love for making perfect copper piping I'm not entirely sure how technical he is when it comes to these systems. I have lots of questions but the thing that's initially baffling me is on the control panel for the heat pump when the ufh is running its shows the flow and return temps are very similar circa only 1 or 2 degree loss between the two. From reading on here that seems far too narrow so the lovely heat the pump is generating heat but returning the majority of it . If someone could help me understand the impact this will be having on the heat pump / efficiency and then how I would go about increasing this difference that would be appreciated. The installer left all flow rates at 2.5 which was nothing like the ufh design I've referred back to, so a few days back I reduced these to what the design recommended, but this hasnt affected these flow and return temps which I assumed it would have. As said for many on here with knowledge in this area it may well be like pulling teeth trying to get me to understand what's going on but I'm game for the challenge Thanks.
  16. There have been so many little problems Ive asked for a break with the builders so I can do more research. Do I recall people discussing that UFH and ASHP might not be a great idea for a rental property? I'm not planning to rent the stables right now but its not impossible in the future. Is that because of the PITA factor and the chance of poor installation/incorrect sizing etc etc
  17. I moved into a 4-bed dormer bungalow (176m2) last summer that had just been gutted, extended and completely renovated, including ASHP for the DHW and UFH. The ASHP is a Nibe F2040-8 (8kW). The UFH is in screed downstairs and on aluminium trays in the suspended floor upstairs (both with 200mm pipe spacing). There is no buffer tank, although there is a volumizer unit. Room temps are set to 18C for bedrooms and 20C for the kitchen/lounge etc (no night-time setback). The UFH downstairs can maintain target room temps with a flow temp of 25-35C. However, the upstairs seems to need a higher flow temp of ~45C to maintain target room temps. The problem with this is that when the outside temp falls below 5C, the ASHP continually defrosts and is unable to deliver a flow temperature >30C (i.e. the opposite of the intended weather effect compensation!). I have attached some screenshots of plots from my Nibe Uplink – the first is when the outdoor temp was ~10C, which shows the flow and return temps oscillating around the target flow temp (which is what I would expect to see) and the other shows the same plot when the outdoor temp is ~2C. In the latter plot, the pump is defrosting so frequently that the flow temp never achieves its target, resulting in high electricity consumption (>£200 p/m), a really noisy pump, angry neighbours, and room temps <18C upstairs. The installer is refusing to investigate this problem and Nibe will only interact with installers. Q: is the impact of the defrosting cycles what you would expect for an ASHP at <10C? If not, any thoughts on the underlying cause – insufficient pump size? Lack of a buffer tank in the design? Anything else you can think of that might cause this…? Looking forward to your expert input and happy to provide any additional details that might be helpful.
  18. Hi all, We are getting closer to having our UFH pipes laid on the ground floor (in 50 mm liquid screed). My design is as shown in the attached image (150mm centres) , however have been told that its not the best way of having it and a spiral design would be better and give more even heating and less chance of any cracks. Is that right or is my design perfectly adequate? All the runs are less than 80m long, I didn't want to go more than 150mm on the centres as I wanted to improve heat up times on the system and the plan was to run the UFH at as low temperature as possible so that the boiler is condensation mode all the time while the heating is on (If anyone has any further information on system design in that respect it would be much appreciated). Thanks
  19. £820 for the quarter. I appreciate it is winter and the pump works harder but I wasn't expecting that. Lighting wise I have the open fitted with spots (only since Dec) and appliance wise (again since Dec) couple of ovens, hob, 2x F/F and a dishwasher which leads me to think the UFH is the culprit. I have looked at the UFH pump (a wilo 25/6) and found that the setting on this was not correct for the UFH so have change the profile as per the manual but couldn't work out what speed to set so went for the medium. I only have 5 zones from the 10 zone manifold active ( four controlled by a neostat) and one zone (bedroom)that is on but with the little TRV so comes on and off with the open plan. area. Flow rates are set to 1.5ish l/m. I have a 40l buffer but have found that when the heating comes on this drains and before the required room temp is reached it empties and I am pumping cold water around the system. None of the floors are warm (which the wife is most annoyed by) although the house does not feel cold. The UFH pipes etc was installed by the screed company and the water works and pump by a reputable plumbers. I connected the flow and return to the cylinder and when the commissioned that they said there was no issues with the plumbing between the two. I would have called someone out to have a look but I am skint now...any ideas please? thanks in advance
  20. How do you decide what speed to set the pump which is on the manifold? The pump which is inside the heat pump controls itself although you can alter the flow rate. At the moment it is running on speed three but that is how it was when it was turned on. TIA
  21. I'm in the early stages of the refurb of a 1917 property in Kent. The rough downstairs floorplan is below - The floor is a real hotchpotch of suspended floor (45% - Green), Previous extension concrete floor ( 35% - Yellow) and New proposed extension (Orange 20%). The current EPC is a horrible 23 and we're looking at using a combination of internal and external insulation to improve this. This may be an opportunity to seal the house (replacing floorboards?) Trying to bring all the potentially different technologies and solutions together is a challenge and every choice seems to lead to a particular specialist supplier that may have a particular axe to grind/product to sell. There is a wealth of knowledge and experience on this forum that I am very glad that I have found. Regards Tet
  22. Finally got the heat pump up and running. After clearing the air locks the system seems ok (?) but just need some reassurance that it is working. The house is obviously very cold (10 degrees) so it is going to take some time to warm up. How long does it take to see some improvement as it went up 1/2 degrees but I also turned on my mvhr today so a few things changed? What have people set the water temp for the ufh? House size is approx 26 x 9 internal floor area and is all ufh on a Passive slab so I know it is going to take a while. When I initially got it running the buffer tank heated up quickly but the blending valve was not adjusted so as soon as i altered that the heated water went into the ufh pipes and all the heat just dissipated so I guess I am after as much info regarding the first time of turning on the ufh and the running of there after, please!! I know you have to warm the slab up slowly but it could'nt get any slower but I am comparing it to rads as I have never experienced wet ufh before. TIA
  23. I've read various threads and views and back and forth and done some calculations based on information I have found here and of course from the very helpful spreadsheets provided by our friend @Jeremy Harris. I had pretty much decided ages ago I would get an 8.5kW Ecodan, which might go up to an 11.2kW ecodan unit. However I have not really advanced it beyond basic assumptions, what others done and some quick back of the fag packet calcs. I'm about to start foundations shortly hence, need to firm up on the UFH design for the in slab pipework and would appreciate some sense checking/ a wee nod that it seems ok. Build is SIPS with Kore insulated foundation, aiming for high levels of airtightness but not near PH (basically as best as I can get it without major hassle), Vent Axia Sentinel MVHR. ASHP which does UFH and DHW (UVC 3-400L tank). Secondary heat source of Log burner (I'm aware it's overkill likely - but I have 2 acres of woods, vaulted ceiling and need a backup in the event power ever went out). I would like to map out the steps in layman's terms to ensure they are right and I have followed it correctly from what I have read, then hopefully the thread can then be followed by others. Step 1 - Heat loss calculation: So I completed the heat loss calculator - see attached. I have a few checks to do on areas and might make minor adjustments but near as dammit it's close enough. I have added the OAT values for my local area (West Scotland, south of Glasgow) from the MET office. Now do I basically just use the 'Total daily heat loss power for average OAT (W)' value to find the maximum based on historical data and that defines the minimum amount of heating system required such below: which seems 3.6kW heat loss for January. The simply - I select a heating system which can supply this amount of heat as a minimum (ignore losses for now). So just simply selecting an 8.5kW unit would do the job easy? Step 2 - UFH design So Having found out the maximum heat loss above (3602W) then we can just plug this into the Heat loss and UFH calculator, which I have also attached. And provides the following output. So essentially, going on bare minimum I would need an UFH system which provides 27.7W/m^2 , based on 130m^2 of floor - so essentially if I don't use some slab area then I need to compensate and adjust the calc. Step 3 - UFH loop spacing So I know the total heat loss, I know how much heat input I have to supply per m^2 if I cover the whole area of 130m^2. So I get loopcad, then draw the circuits. Aiming for counter flow circuits as they provide the best option for even heat distribution, keeping circuits less than 100m in length. Now this is where I get a little lost, I have a figure of 27.7W/m^2 for the whole area to get my required heat input, however how do I correlate that with loopcad and also deciding what my spacing should be?! I have seen @PeterW mention quite a few times about the the spacing had to be adjusted but I am struggling to find the route here to confirm easily what it should be. My loopcad drawing (I've attached my current draft) showing for example 105W/m^2 in my living room, but I'm not sure how this should read in relation to my calculated figure. I'm pretty sure I'll need 200mm centres, but I'd like to ensure that was right. I've some adjustments to make to my circuits, but it's not far away. I was finding that the auto generate function for pipework isn't ideal but it works ok. The garage can be ignored - I ma installing pipework in there pre-empting possible future conversion of that area and hence pipe is cheap, so why not add it now. The manifold will go below the stairs - seems to make sense to me, I have a plant room directly adjacent and was going to put it in there but seemed better to get it out of there as I will have lots of ducts and this would clutter that up. Is it ok to run underneath the stairs? I assume I just have to tell the Joiners not to fit the stairs to the floor with big screws?! Step 4 - Zones I am only having downstairs heating, so it is a single manifold. I would prefer as few zones as possible, but a single zone wont work. I was thinking I can have two /possibly three. Zone 1 - Main family room area Zone 2 - Everywhere else excluding shower room and garage Zone 3 - Shower room Zone 4 - Garage (permanently isolated at the moment. I assume you can have multiple zones on a manifold, and can just split them up by using salus actuators?. So a single thermostat for family room can control three loops (each with an acutator) in that room? and so forth?. It's a long post , and actually I wasn't going to talk about zones but thought it was worth adding in. Thanks. Heat loss calculator - SuperJohnG.xls.xlsx Floor heat loss and UFH calculator - SuperJg.xls.xlsx Looopcad - SuperJohnG.PDF
  24. Hi, I had a mid life crisis and decided to rip out the central heating system and install underfloor heating 😀 The project isn't finished yet, but most of the rooms now have heating. This is a retrofit system using overboards with pipes laid in them at 150mm centres. I have a couple of questions that I'd like to get a better understanding of (bit late, I know!). Q1 - Efficient UFH temperature I don't know much about thermal dynamics, so hypothetically, if I have a system that loses 1 degree per hour when the heating is off, and it takes 1 hour to increase the temperature by 1 degree when it is on, would it be more efficient to let the heating go from 21 to 18 over 3 hours and then from 18 to 21 over another 3 hours, or would it be better to go from 21 to 20 and then back to 21 every two hours, or doesn't it make a difference? The reason for this question is that I'm thinking of leaving it polling constantly between 20 and 21 degrees. Q2 - UFH max floor temperature dilemma I currently have the manifold set to 42 degrees. This is taking a lot of time to get up to room temperature (5-8 hours, and it's not even winter yet!). The problem is, if I set the temperature any higher then the floor gets above 27 degrees (tested with an infrared thermometer, although this may be inaccurate?), and as most of the house is laminate, I believe this is not a good idea. I did think about installing floor probes, but I figured that once the floor got above 27 degrees, the heating would cut off until the floor temperature dropped below 27, which may protect the floor, but would defeat the object of trying to heat the house, albeit heat would still be coming from the floor? I also assume that once the temperature drops outside in the winter, the floor won't reach 27 unless I increase the output temperature from the manifold, so it will be a juggling act through the seasons? As you can see, I didn't think this through first 😂 and I hope I haven't left out any vital information in these questions. Still glad I did it though! Regards
  25. Hello guys, I have searched google but I could not find an answer in my attempts to find out why the red cap flow meters of UFH systems are always fixed on top of the manifold, and the actuators are placed below. Could anyone explain, is there a specific reason why is it so? Is it allowed to fix them contrary, and would that have any negative consequence?? Thank you for your answers.