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Will chk this eve. And report back......thnx

Does the front fascia plate allow access to those two brass hex inserts? Eg, when installed, will they need to be tiled over or is the plate big enough to have them left accessible?

Indeed........on borrowed time!

Missed off @jimseng from here. How do people learn about calculating the heat output from UFH for a given room size and heat loss? Any recommended books/reference material/youtube accounts/online courses? I’ve been wondering how the downstairs heating might perform if we had wider spacing in the living room compared to the other areas, and where to put the thermostat as the whole of the GF will be single zone 🤔🧐. Even just as an exercise, I’d like to be able to work through the calculation as an exercise. Has anyone done this before?

Couldn’t agree more - fear not, I do this too 😁👍🏻

Where to start. I'll try to set this out logically. I thought I'd landed on a plan for how to go about the ASHP (and by close association, UFH), but as we're now going for a smart home using KNX, the ASHP we were looking at doesn't have native KNX integration and so I'm taking a fresh look at this. Many of my issues chime with that of ___ in this thread - https://forum.buildhub.org.uk/topic/46547-how-can-i-roughly-calculate-ufh-output-at-given-flow-temps/ Bottom-line: We need an ASHP, 300L DHW cylinder and UFH design. Passive-level of insulation & air tightness (MVHR planned - DIY, Zehnder Q600). Ground floor height = 3m, First floor is into the roof space (steep pitch) - ceiling = 4m. Open void at the entrance to a double-height space. UFH - 111sqm ground floor only, single zone, spiral pattern, multiple circuits. Upstairs will have electric towel rails and UFH mats in bathrooms just for the ‘warm floor’ feeling rather than to heat upstairs. I’d like to vary the spacing so that the single zone system heats the rooms at a different emitting rate (bear with me) - the thermostat will only be set in one location, whilst there are 5 separate areas (living room - no opening window), study (small, has an opening window), hall (massive tbh), WC (tiny), Utility room (clothes hanging to dry), Kitchen/diner (massive and huge sliding doors). I’m suspecting that I may struggle to get this ‘done the way I imagine it could be’ as all the companies just roll out a default - same spacing everywhere plan. AC - detailed modelling shows we don’t need cooling, but we’ll install power to the locations where an AC unit could be installed, but we plan to live in the house without it. Shade is ‘not a problem’ we have plenty. Smart home integration - we’ve managed to get a KNX designer on board at a manageable cost and so want to ensure we can integrate the heating into it as the KNX controller could negate the need to duplicate having an ASHP controller separately. KNX is a protocol rather than proprietary system and so is widely compatible, but I’m looking to choose one that is directly compatible rather than via a 3rd party controller; I understand Vaillant and Panasonic are just 2 examples that are compatible. ASHP - I’m no plumber and lots of threads (here and elsewhere) refer to ASHP only being any good if they’re set up well, and getting someone who knows the specific make will know how to get the most out of it etc, etc. I’d love to learn this stuff, but I don’t have much time and this feels like something we should be getting done by an ‘expert’. The plumber (via our builder) doing the rest of the house is not familiar with ASHP and just needs a flow and return to connect up our UFH, but his only experience is system that have a buffer and when I started describing having a simple / optimised system with no buffer, if wasn’t clear to him. He’s clearly practical at all other aspects of the plumbing, but not one for designing a system. We’re approaching the point of laying floor insulation and being ready for UFH will be straight behind that. I’ve got UFH quotes for design and supply, but I’d prefer to need a plan, and the relationship between the UFH (d Options (there are undoubtedly more that I can’t think of - it’s late…): Contract one company for ASHP design, supply & install, with UFH design & supply (some of the MCS quotes have insisted on having upstairs emitters as the calcs won’t workk otherwise (apparently - I’ve got no way of knowing if this is correct). Rely on my heat loss spreadsheet calcs, purchase ASHP direct from a supplier (not sure how to install - is it as hard to set up as I’m led to believe?, do they come with instructions), get a company to design & supply UFH, lay the pipework myself and get our plumber to help connect it up, if we need. Something else?… Grateful for your collective advice on ASHP options that will be KNX compatible, and how to go about our design/install. Our journey so-far: Pre-buildhub days: NSBRC, Architect recommendations… approach ‘Renewables company x,y,z’ Single ‘do it all’ coherent blah, blah, (all sounds great until the crazy quote eventually arrives). Oh, how little we knew then! Local self-builder: Sheer luck, came across a local self-builder whose build was almost the same SQM, very similar passive-level performance, UFH downstairs only and only needs a 5.5kW ASHP (Samsung). This gave me a yardstick for what we would be expecting. Initial research: ASHP theory, all quite straightforward (in principle - reverse fridge etc…). Find a local ASHP firm that had a good sales pitch, MCS registered, quote didn’t take the ****, but scratch the surface and they really didn’t know the maths and understand WC curves and flow rate details. Seemed to very much be a UK office where ‘technical’ was more on the practical installation rather than actually calculating how the setup should be done. Buildhub reading began in ernest: Jeremy’s heat loss spreadsheet - https://forum.buildhub.org.uk/topic/439-fabric-and-ventilation-heat-loss-calculator/#comment-4407 (everyone seems to find their way to this eventually; I put this off for a while tbh, I deal with too many spreadsheets at work, I wasn’t actively searching for more). Measured everything up, ran the numbers, ~4.5kW before factoring in DHW. Quotes: Throughout this journey we’ve had blips of focus at trying to ‘commit’. We’ve had quotes proposing 14kW (WTF!), lots of default ‘buffer + pre-plumbed cylinders, no questions about UFH’ and the list goes on. Who to trust: I really struggle with working out which company actually has the competence to *design* the ASHP & DHW cylinder installation optimised for our build. DIY vs MCS: As I’ve learned from threads on here, the cost of parts can completely negate any benefit that the MCS grant suggests. There have been 2 quotes that have actually brought the cost down to zero/near zero through an MCS umbrella company, but I seem to recall there was another reason they put me off (will have to dig through the quotes & emails…). I would much prefer to have a system that we have someone to go back to if we have a problem (plus I don’t know if our building warranty will want some guarantee behind the install - just remembered as I type that I need to check this). Landing towards entrance void.JPG Hall towards plant.JPG Kitchen-Dining.JPG Living.JPG

Don't cheap out on the choice of unit Get everything else you need from begging / stealing / borrowing, but the beating heart should not be bean-counted. Remember this....you will switch the MVHR on, and then NEVER turn it back off again for the rest of your time in the dwelling. If you choose poorly here, it'll not pay dividends from day 1, plus it'll come back and bite you on the ass when it fails early. Also make sure you pay homage to box attenuators before the distribution manifolds, as noise needs addressing. If you buy a compact (cheaper) unit, it'll have inherent problems as 'size matters' here I'm afraid. Look for units which have pre-heaters as an integral feature, so the unit doesn't shut down when incoming air temp comes close to freezing the unit. Brink for me, great price for an excellent unit. Watch for grey imports as they are 'return to source' warranty only, and do not come with on board controls; you need to buy these as a bolt-on, and then all of a sudden it wasn't so cheap after all.

Oh interesting, so in simple terms its limiting to 400mbar because the boiler wont let it go higher? Knowing all this would the plan for adding the Wilo Yonos Pico as an extra external pump still be valid? as I was still planning to do that after the WB boiler guy takes another look. I dont want to over complicate the setup before they come back as in my experience that makes it easy for them to point to other things as a cause of the problem. Currently there's nothing external other than the mag filter and extra Expansion vessel.

They cancelled on me and are coming on the 6th Feb now to look at why its still overshooting etc.

Not so with the Ivar sets. Totally different beasts, have you used these before? How do you achieve disenable segregation of the GF and FF if there not two stats (and therefore 2 zones)? Not a stab btw, I'm still at school every day I'm concious. This... ....with this on top. When we know 'TOG' and anticipated floor coverings, plus the GF situation. Don't worry about it, but don't discount it quite yet, is my 2 cents. It would be a bugger if you design for x floor coverings, and then cannot have anything else, ever, in its place for eg.

Telling people they've done a good job, and that you appreciate it, goes a loooooooooooooooooooooooooooooooooooooooooooong way. Don't put that off

Hmmmmmmm. So, here's the facts Stud walls for bathrooms should be at 400mm cc, not 600mm. The weight per m2 is the concern, but if your tiles are that big then......so what? It's still exactly the same kg/m2 as you putting 100x100mm tiles on. If the tiles you bought are 30kg/m2, then so will tiles 25mm x 25mm be. It's physics. Where you apply the math is the board and the way its fixed, so you'd be going for 12.5mm MR PB (if I was doing it) and then screwing it to studs at 400mm cc, and having a screw into the PB at every 100mm max cc. Then you could patio slab the damn walls. If you have studs at 600mm cc then you (or I) would then be installing horizontal noggins to create 400mm cc horizontally. This would give you boxes of 600mm x 400mm which you'd then divide the installed weight of your BFO tiles, per that exact amount of area. You've not been reliably informed. I've been sticking BFO tiles to bathroom walls for 3 decades, and not one's fallen off....yet. I've always used plasterboard, and always gone bat-shit crazy on studs and screwing the MR PB to them. Then I tank the shit out of everything, to the point people think I need help, and the results speak for themselves. No need for fancy XPS boards, cement or tile backer boards, all just stuff introduced so it can be sold to folk to turn a profit. "No".

We keep them all well stocked in a bottomless supply of decent snacks, drinks, tea & coffee. But yes, there will be beer at some point.

Nope. This is spot on. The internal of the black cowl is sat atop the roof penetration 'top-hat', and that keeps the rain from getting down into that junction. It needs to be high enough to stave of splashing rain. Buy him a beer, and say "thanks", it looks very robust and a good job afaic.

Ahhhhhhh! I've seen this before, and I think we're in quite a predicament here, so sorry to be the bearer of bad news. How can I say this......I guess just come straight out with it I suppose........here goes........................................ Questionable rug.

Yes, have been speaking with the heating engineer. Looking at the options on HPs at present. @JohnMo thanks for the input. Direction is low power HP, reasonable cylinder size of 300l or so, wet U/F and as per @Iceverge electric u/f in bathrooms and electric towel rails. On the MHVR I am investigating options as I am very tempted to DIY as I believe I can probably do the lot for 4-5k in a week myself with a spare pair of hands from my wife.

Yes, you're right on the overheating. I am inclined to not commit to anything on that front as I would rather run the system for a year and see how we manage. If we find we have an issue then we would maybe consider split air in one of the main rooms. 1% over 25 degrees, I believe peak was 26 degrees. Not sure on the solar gain impact of the PV, I assume it is embedded in the PHPP methodology as the calculation takes input on the array size. Location is Bristol, non coastal.

I'd seen it initially when it was all loose (waiting for the EPDM seal to be installed) and just assumed the black section with the splay would go down to the floor, that was all.

It's been a while since I had to work nights, and had various instances of particularly long shifts to press through. I'm definitely finding that they have prepared me well for this 'experience'! Personally, offloading some questions into this forum helps me. I have the notepad and pencil (tick), copious use of the iPad and the 'Procreate' app to annotate over images and drawings, but I typically find it takes a while to wind down from the day job and then spool-up some motivation to try and articulate the issue/challenge of the day. Then, a bit of Buildhub research before posting allows me to get the question out into the ether and hope that the following day an answer or two has nudged me a little further along. Secondly, radio 4 comedy shows are an easy listen and by then I'm normally shattered. Just know you're not alone in the challenge @ToughButterCup! Thanks for starting this thread.

This all looks fine to me. What is your concern?

TBH, on mine, if I lean forwards and go over a bump when my main boom is fully retracted, I almost get head butted by mine. I've been meaning to get new pins & bushes but like you say @ProDave it stll works fine, just with a good few clunks sometimes.

Pressing the new bushings in should be straightforward using a threaded bar and a socket. I could be wrong and it requires way more force than I'm thinking it does.

The cement faced foam core boards can be skimmed, but you use a specific primer. definitely not pva.

My old digger had a LOT of play in it. It did not stop it working and it did not get any worse while I had it. I just used it and spent my time building, not fettling.

Very strange indeed but it's not entirely impossible there's a bad batch of seals or heat exchanger a floating around. It would be easy enough to set up a rig to pressurise one side of the unit and see if it leaks out. I'm thinking a couple of bungs, a Schrader valve and a bicycle pump. Pressurise the exhaust(or inlet) side and see if it leaks out immediately. Perhaps something as simple as a dab of sealant would be enough to cure it.