jack

I've used underfloor cooling for nearly 10 years (didn't use it the first two or three years after we moved in) with great success and zero issues. Panasonic's UK technical team were hugely supportive while I was trying to get the ASHP working efficiently in UFH mode, but they were very cold (pardon the pun) on the idea of underfloor cooling. I think there's just a strong bias in the undustry against it, probably due to a combination of risk-aversion and ignorance. If you're only planning to use it now and again when the heat build-up in the house is getting too much, it literally needs nothing other than a switch, or maybe a timer, connected across the ASHP "cool" terminals. Our system is slightly more complicated, because I control it with our home automation system, but it's still fundamentally just acting as a smart timer. All it does is close two relays when certain conditions are met, one of which puts the ASHP into cooling mode and the other of which turns on the UFH pump. You could do similar with a timer and thermostat. Our UFH is run as a single zone downstairs, with the water temp set at 15 degrees. Never had a moment's problem with this setup. We get a whisp of condensation on the exposed metal parts of the UFH manifold, but that's it. No need for complex controls or subscriptions etc. I can't imagine how it could get any simpler. Fabric-first is important, for sure. We have exterior blinds on most windows that benefit from them, PassivHaus-class insulation and airtightness, and good overhangs on many east-, south-, and west-facing windows. Even with all that, upstairs bedrooms can easily get into the high 20s during long periods of hot weather. That comes down a bit with the downstairs underfloor cooling on. The ground floor can easily be held at a comfortable 20-21 degrees. I obviously don't know what downstairs would be like if we had no underfloor cooling, but I can tell you how lovely it is to walk downstairs in the morning during hot weather. It's like walking into a cave or a cathedral. The cool floor sucks the heat out of your feet, which is a very pleasant way of staying cool. Having spend many years living in a hot country, I really dislike the way aircon dries the air, so for me, underfloor cooling is just a no-brainer. If I were building again, I'd personally consider installing UFH under tiles on a thin screed upstairs and cool that during summer. During winter, I'd put rugs down and maybe run the UFH just enough to keep the chill off if needed during the coldest spells. The only thing I'd add is that all forms of underfloor heating and cooling will be more effective if the floor is made of a thermally conductive material such as tile or concrete. Wood isn't as good, and I guess even low-TOG carpet is worse again.

+1 for Whitewing over Loxone mains dimmers. Also, the DMX extension is useful for other things. DMX relays are cheap. You can buy multi-channel, DMX-controlled, DIN-rail-mountable relay units for a fraction of the cost of the Loxone equivalent. Alternatively (or in addition), you can put indivudal relays or multi-relay boards closer to where they're needed and control them via DMX. In a larger installation you need to consider signal cable length and topology, but other than that, imo DMX is a robust solution to a lot of problems.

Wow, that's a great looking location and project! Absolutely 100% fine. Codes vary across the UK too, so we're used to that. There's an "Ireland" sub-forum (which I've just noticed is embarrassingly under the "UK" heading - sorry about that!) that deals with stuff like local suppliers, building regs, etc. Pretty sure it's used by everyone from the island of Ireland. More generally, unless your questions are specific to your location, the best place for them is usually the relevant subject sub-forum rather than the location-specific one. Looking forward to seeing more about your project as it progresses.

I've managed to identify the stuff I used to seal/bond between our garage door frame and the surrounding engineering brick (slips). It Soudaseal 240FCl. Hybrid polymer sealant adhesive Soudaseal 240 FC combines sealing and bonding applications on all porous and smooth surfaces. Its high quality Hybrid Polymer technology warrants outstanding adhesive performance, permanent elasticity and long term weather resistance. High chemical resistance. Meets ISO 11600 F20HM. Suitable for sanitary applications. Featured properties High modulus hybrid polymer sealant & adhesive Damp surface adhesion Conforms to ISO 11600 F 20 HM Over-paintable Silicone & isocyanate free XS1 fungicide Applications Strong bonding which requires elasticity and high end strength. Bonding in vibrating constructions. Flooring joints in construction. I'm not sure who told me about it, but it's really impressive stuff. It still looks as good as the day I applied it over five years ago. It's not super-flexible but it's very tough. I also found it fairly easy to apply and get a good result, using masking tape, and some soapy water for smoothing. It's also not that expensive for what it is - less than half the price of CT1, for example. No idea what it's like for use in bathrooms etc (although it does have a fungicide), but for exterior work where you don't need something highly flexible, it's brilliant.

We used tens of tubes of the stuff to stick brick slips to walls inside our house. Not a single one has budged in 10 years.

This thread hasn't been visited for a while and it's pretty unlikely the original poster is still monitoring it. You can tag people you want to know you've posted by typing the @ sign followed by their name: @k dawg Depending on their account settings, they might be notified by email that someone's tagged them. Beyond that there isn't much you can do but start your own thread and see whether anyone can give you advice on your situation. Good luck.

(Moved as requested by original poster.)

We have almost the identical situation on a large wall high up in a double-height section in our kitchen. My best guess (based on our experience) is that it will be exactly the same when you paint it. I doubt you'll be able to completely sort it, but you could try some judicious sanding with a long, flat sanding block to knock the high spots off, followed by careful application of scraped on filler with a wide trowel to fill any low bits. The affected wall in my house is almost east-west, with a large window to the east. In our case, there's only a short period - a few minutes, I guess - on sunny mornings in Autumn where this effect is visible. We decided it wasn't worth trying to do anything about.

@vishusingh, you've come to the right place. Must of us are amateurs who've found (sometimes had to find, like you) our way through difficult and complex situations. There are also some very experienced people who give their time freely to help. Post your questions in the relevant sub-forums, and no doubt someone will be along to help. Good luck.

Yes, power is the rate at which energy is delivered, so power = energy/time. My comment about time was in response to the poster asking "what duration" the 3 kW heat loss was over:

You can get induction pads/plates that sit on the induction hob, allowing you to heat non-ferric cookware. This sort of thing. I wouldn't use them as a permanent solution or where large power output is involved, but for a moka pot I reckon they'd be fine. Do your own research though!

That's a tidy-looking house. Great to see MBC in action. We used them over 10 years ago but still have great memories of their work ethic. They were one of the few trades we had onsite where there were minimal problems, and those that did arise were addressed immediately without argument.

Same. Our house temp changes about 1 °C per day with the heating off in the winter. Having no heating on for a couple of hours is imperceptible. Compare that to old Victorian houses we've lived in, where the temperature would change several degrees over only a few hours.

'kW' is power, so it's a continuous number. There is no time component. If you want to know how much energy the house uses, you multiply power by time. For example, 3 kW of power supplied for an hour is 3 kWh (the unit electricity is charged in).

Great thread @Nickfromwales I've pinned it for visibility.

It's not really an article, more a tool that shows the cost of wind generation curtailment and paying for gas to make up what was curtailed. The other info is just very brief (line or two each) commentary about what the page is showing and how we might improve the situation.

@Oceanjules, FYI I hid your duplicate post over in 'General Joinery'. It's generally better to keep discussions to one thread, and I think this is the better sub-forum for this topic.

Any or all of what I said might be wrong, but that's exactly the point I was discussing:

I remember reading about someone (maybe the guy who did the Denby Dale Passivhaus) putting the outlet of his MVHR right behind the ASHP, the thinking being that the ASHP would recover some of the additional heat from the outlet air being slightly warmer than the ambient air. Personally I'd be worried about differences in pressure (between the ASHP being on and off) unbalancing the MVHR. The moisture point is an interesting one. When it's very cold, at least some of the outlet air moisture condenses on the heat exchanger and goes down the condensate drain. I don't know what proportion of the moisture exits the MVHR outlet, but if it's [corrected typo:] not a lot, then the impact on icing might not be that significant. Also, when it isn't quite so cold as to cause increased icing (and hence more defrost cycles), moisture condensing on the ASHP fins will improve efficiency, because of the large amount of energy released due to the change of phase. I suspect the whole thing is too complex to easily model. The one thing I would try to do is to direct the MVHR outlet air towards the far side of the ASHP. With a bit of luck, the outward airflow from the ASHP might entrain some of the air from the MVHR outlet and push it away from the house. Some sort of baffling or screening could also help encourage the "right" sort of air movement overall.

200 mm seems small. Have you checked your ASHP installation manual? I have a very low capacity ASHP (5 kW) and I believe the minimum spacing from the wall for that was 300 or 400 mm.

Not 400 m2, but I have a four bedroom, 289 m2 house where I've been successfully operating my UFH as a single zone for nearly 10 years. It's a very well-insulated house so there's no heating in the bedrooms. We do have panel heaters in the bathrooms that get used in winter, but that's it for heating upstairs. I suppose if I had wet UFH in the bathrooms, I'd want to run those on a separate zone(s), but that's about it. As for different rooms requiring different heating outputs, that's just a set-once adjustment using the manual manifold flow controls. I haven't bothered - they're all just wide open. Also, if you know in advance that you want more or less heat in a particular room, you could adjust the pipe-spacing accordingly.

Welcome to BuildHub David. I've removed the company name from your posts. I'm definitely not saying you fall into this category, but new members sometimes express a positive opinion about some supplier or other in their first post, and with a bit of digging we find out they're an employee or director of the supplier. The link isn't always that obvious though. Since we're a strictly non-commerical forum, we don't allow people to post supplier opinions without some sort of posting history. Thanks for your understanding.

@Mubbashshir, I've merged the two threads you started on this topic.

FYI, this was a spammer (posted a spam link later in this thread), so his post has been hidden.

Awesome, you were playing the role of "Airtightness Champion": https://carbonlite.net/wp-content/uploads/2017/04/Aldas-12-Steps-to-Airtightness-revised-June-2019.pdf