Nickfromwales

I’d have to argue about that with you, as the numbers don’t lie. I had feedback from the PV installers for the first years figures on just how “unbelievably well” the array was performing, the clients words and he was not a daft boy. If you read my above, the remit was to have these installed so as to not bastardise the landscape, and if they WERE to be sat at a horribly unsympathetic angle of 45° then 1), they would have been quite ugly to look at and 2), they’d have needed MUCH bigger distances between rows to prevent the forward most panels from completely shading the ones behind them . A mono-pitch roof / array? Or 3 rows of panels banked one behind the other…..? So for comments or a fair comparison, “apples for apples” plz. How many Watts per panel are yours? I assume 540W per, by the rough maths. These panels were German-made Solarwatt Vision 325’s, glass/glass, as the client wanted them to be as robust as possible and take impact from flying debris, otherwise we could have installed much higher output cheaper Chinese-made panels to boost the output. With a 30 year @ >90% performance guarantee the SW panels were a no brainer, as longevity of the installed equipment is paramount to preserve the indicative ROI. If the array fails early, goodbye payback. 45° is a wonderful angle, I don’t disagree, but not here and not for this client. No 2 projects are the same, nor are any 2 remits, so we work to the client and their remit and treat each self builder / new client uniquely. No copy / cut / paste for me, as I feel that is just a lazy way to do things and quite a disservice. Discuss, summarise, discuss again, and only then do we crack on; eg only when the client has been given enough information and can then make their own informed decisions 🫡👌. Also please understand that this was put through MCS etc, so anything less than admirable install wouldn’t have got through the software at the design phase so it HAS to perform adequately, at the bare minimum, to get through these preliminary measures of due diligence; we do this on paper early on for every install, eg to firstly see if there’s a valid reason to NOT install PV etc. IIRC, less than 70% irradiance is a fail. To combat the reduced irradiance of the shallower angle we designed this particular array to feature more panels than was required, peak summer, to offset the reduced output from the remainder of the ‘solar year’. Again, the numbers were known, discussed, and understood comprehensively by the client long before a deposit was taken. Hence they have more panels than you, but less gross output than you. As I said, this array is spewing out power for a lot of the year, and was placed to get sunlight from <08:00 - >18:00 peak summer; dependant on certain trees remaining crowned / surrounding (client-owned) woodland being managed. Winter is a shitty time for any solar array, it is what it is, but numbers and results speak for themselves .

Yup. He agreed to give it ‘very regular haircuts’ lol, so we agreed to ‘flush fit’ it down as low as possible. He was concerned more about the ramblers, whom he had given access to cross his property to, regarding this not being an eyesore for them! Planning etc was almost a secondary concern lol. Theres about 6kWp there, external inverter hidden in there, and AC was exported 135m back to the house. Performing extremely well as we could pitch and orientate it to maximise irradiance. There was zero chance of getting on the (diminishing course stone) roof of the 200 year old listed cottage…. We dared not even take the moss off it!

Ah, ok lol. Thanks. ☺️ I’d definitely be beefing up the two standard radiators then, looking at location they could become type 22’s without impact? Vertical rads don’t do a great amount, and please realise my focus for the end result is always on the adverse weather days, not just ‘everyday’ . I won’t install a system where the client turns the room stat up to 22°C and the system cannot get there / struggles to get there, because it’s blowing a hoolie outside and it’s -3°, and you should be looking for lower flow temps. One get out of jail card is to turn the violet flow temp up during the worst of the winter months, but then efficiency will suffer when you need it most.

Annoyingly, anything ground mounted over 9m2 requires planning permission, but I believe this is waived if it’s on a raised framework which is then, technically, not a true ground mount ?!? This country has some bloody weird and often obtuse rules and regs, and you’d think adding solar for the good of the environment would be less hassle! Considering the massive solar farms we get to look at, and wind turbines, a ground mount of 9m2 (less than 3 domestic sized panels) is a garbage allowance. For completeness, the above array went through PP first time with zero objections, as we planned and executed it as sympathetically as possible. The client reports that it is outputting some very high numbers all summer long. 👌👍

If this isn’t ’impossible’ or impractical I would definitely put solar at the top of the list, as using electricity for the rest of your days is going to happen, and only get more and more expensive to do Is there much of a cost impact to do the report?

👌

There's your first very bad idea, sorry. And here's why: Why use the immersion less and heat everything else with other direct electricity? The water in the cylinder, via the heat pump, will be abundant and cheap as chips!!!! Do NOT fit an electric shower, or any other instant water heaters, as these are all the last resort when you have no possibility of fitting a hot water tank (or combi boiler). Can you do a ground mounted array? I'll post some pics of one we've installed for clients previously, in an area of outstanding natural beauty, and a conservation area, and it passed with flying colours. Yes, but it's messy, complicated, and I doubt 'sensible' when you have such cheap hot water already.

Can you update us on the house type / construction / airtight etc please? Are these not in thin spreader plates directly below the deck boards (P5 Egger boards)?

That 1800x420 on the long left wall....why is that a vertical? That should be a double rad, same height as the 600x700 and then the '1800x420' rad should be sent much further down that long wall, eg towards the bi folds. That arrangement will create a cold 'end' to that room as the vertical rad to the right of the bi folds will do next to nothing unless it's roasting hot. You show T50 which is not much use to a vertical / decorative radiant panel like that (which doesn't convect well at all). If you aren't having 2x vertical down there, and the one one the long left wall can be a big type 21, then you'll be fine if the other 2 600x700 are both type 22's. Type 21's do look far less intrusive in open areas, but you still need more heat in that space imho (I've been installing CH for 30+ years btw). If the type 22's don't fit the spaces they are in, then simply make them longer type 21's. Much better to be turning a big rad down, as you cannot turn a small one up , plus if you then end up running much higher flow temps the boiler efficiency will drop off at a steep rate.

Hi. As the 1st floor of the property is within the heated envelope, the insulation your architect suggests is completely unnecessary (redundant). 25mm would do the square root of zilch anyways with UFH, so the subfloor would get heated regardless of it, and I personally think you'd be better off with the thicker screed atop the (22mm?) deck boards. You simply lay the membrane, tape and staple it down as required (do a good job of this), then clip the pipes to the deck with clip rails or simple nail clips, and pour the screed. Prob a good idea to put expansion joints at each doorway / threshold as this will run at a slightly higher temp than is 'ideal', eg so it is responsive and can cope, and will therefore expand and contract a little more than say a slab would; not so important with wood floor, but defo at any transitions (wood meets tiles of a bathroom etc). Without seeing the house or being in possession of any proper details that's the best advice I can give here of course

And on EPS, anyone who says they haven't had at least a minor blowout was either very lucky, lying, or braced it all enough to make a bamboo scaffolder happy

Yes, was a shock for that client, but even with very meticulous builders on site that was the max undulation that they had to overcome. There are different experiences from different members, please all remember that these are simply my experiences and folk can do as they wish with the info, but I am an advocate of people knowing there's a hole in the ground ahead of them, vs offering them a ladder to get out after they've fallen in said hole.....better to know the pitfalls in advance of making a choice, and then you have the ability to make your own, informed, decision. @MCoops are you decided on a type yet? Just I can adjust the info to be more focussed on the preference vs generalise etc, to get you over the line a bit quicker. Are these to be dwarf walls, or full elevations with a full oak frame within?

Ok, thanks, I’d never asked the question, but interesting to see them how Isotex seem to have tried to limit the bridges. A very different block to the Durisol. Velox different again as it is a totally separate internal leaf after concrete, this offering up the best option for an airtight build, but still needed a huge amount of time / labour / materials + liquid AT membrane (Passiv Purple) to parge and seal to airtight before dot n dabbing. Just sooooo much additional work. 🤷‍♂️😵‍💫

Nudura had a major advantage of being an 8’ long block which gives quicker lay time and straighter walls. Annoyingly it’s a Canadian product ,so the inset nylon(?) fixing strips are at 405mm oc, so our metric 1200x2400mm stuff doesn’t work. Shame they can’t do a different stock model for the UK, but it may be we just don’t buy enough of it. Will need battening then board, unless you become inventive and are happy to stick the boards together and keep the joins away from the strips. Can be done, just an additional consideration when costing up the gross figures. As far as wet plastering directly over woodcrete (if that’s what you’re referring to) then you’re in for a surprise as to just how hard that’ll be. On the Velox build there was an annex done first off, full wet plastering directly to the woodcrete, and required a lot of sets to get it ready to skim. Ended up around 30mm thick overall. The dried out walls had a visible crack around every single block, like the walls were painted over Lego. Took a lot of additional painting to deal with the enormous amount of locked in water that then sat in the woodcrete / bonding / skim etc, like best part of 6 months with heating and MVHR running. Not sure if they carried on displaying the cracks, but they were unhappy enough to take my advice and dot n dab the main residence. The unevenness in the cured woodcrete ICF was nowhere near close to taking a few sets of skim to a finish for paint. The sales patter may suggest this is easily achievable, but it ain’t. 👎. The clients wallet was hit HARD, getting this to an acceptable finish. Very hard. EPS ICF can be buffed out with surface rasps, and is very easy to rid of any undulations. EPS cuts quickly and easily with a hot knife, but woodcrete is a PIG to chase or remove for services. I ended up using a 22mm SDS wood chisel and it took forever installing cables and pipes at the required safe depth.

Worse copies imho, as the block has way more woodcrete bridging between the external leaves to the internal ones, eg far more pathway for air / infiltration and obvs water / rain ingress etc. I'm not posting negatively or argumentatively here because I woke up on the wrong side of the bed btw, these are actual, hands-on, real life experiences that I have had from gaining 1st hand experience, whilst physically being on these projects, and from being on site for the duration from pre-construction right through to completion. I'd be interested to understand which of these manufacturers were early / late to the table too, before I suggested one copied another perhaps? The achievable U value with Velox, for eg, must be far in excess of both Durisol and Isotex, as the concrete core is completely enveloped in EPS, with just multiples of small cold bridges from the metal ties. If you look at all 3 systems pragmatically then this is inarguable, by the design differences and not just my conclusions, and these are the fact based findings of myself, at least.

Yup, as long as you have the depth for the pipework not a problem. You'll need to bin the pan connector that comes with it and get one of these : https://www.ebay.co.uk/itm/133894857870?gad_source=1&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338723872&toolid=20006&customid=Bz5Fkp0jAAAAfGvQfV9LRaaPpc8NAAAAAA The 3" to 110mm adaptor that is supplied with the frame goes on to the new part, and then that goes to a standard UK soil pipe fitting. 👍

Combi defo the right choice if you’re never intending to add solar. If only 2 of you then it’s a no brainer. The cost and disruption to the whole of house plumbing to retro fit an UVC here do not make sense vs the ‘slight’ uplift in gas use when opening a hot tap; bearing in mind you only ever do so WHEN you WANT hot water anyways? There are just too many good combi’s out there, and if the remit is for lots of pockets of hot water through the day, hand / dish wash etc, then the likes of the Vaillant 938 (their heat store combi with 15L of stored hot water on tap) is the weapon of choice. Fitted loads of these and it’s as close to having a UVC as you’ll get without actually having one. 👌. Combi all the way here afaic. 👍

I have direct experience with both Velox and Isotex (both are woodcrete) and these blocks do harbour moisture, transmit it through the block, and are very different to use when stored dry vs left out in the elements. They do dry out, when kept dry though, but are like a coarse sponge vs a teabag. With woodcrete there was defo a presence / visible signs of moisture in the product within the dwelling, particularly on rainswept elevations, but not with EPS, at all. Agree about free flowing under gravity, as that’s how water (rain) was getting inside the builds. It was notable on the lower 1/3 - 1/2 of the internal leaf, but was sopping at DPC. This was its worse at window and door reveals. The sub-contracted builder on that particular project was a very fussy chap too, so this wasn’t down to poor workmanship, quite the opposite in fact as in ‘it’ was getting a helping hand from that chaps team; they were learning and mitigating as they went, to allow for such inadequacies, through his diligence and perseverance. I’d say these types of builds should have the external rain-screen on asap. Regarding EPS ICF, I have never seen the same, and I’ve been around enough of them. A brilliant product in comparison and will always be my go-to when a client approaches me with an enquiry and a preference to do an ICF build. I'm also not a fan of the block having a bridges, or many bridges per block, capable of allowing air flow or moisture to wick, and with EPS ICF you don’t get either as the bridges are either EPS, synthetic, or stainless steel. 👌.

Thanks for this feedback. No need for apologies, folk comment here on their current experiences, if stuff changes then what you’ve done is spot on, eg come back and tell us 😎😉🫡 Not just me that thinks they’re boat anchors. Defo oversold in the ‘bumf’ and failed to deliver big time for me (certified Passivhaus project where I was attempting to shine). Cheers HW 😤. Since replaced with Heatmiser by a local sparky, and I wish I’d have not stuck my neck out with HW EvoHome, hindsight being a wonderful thing etc etc. HW are great for just about everything else, but here, sadly, a complete flop. When you boil the HW EH down, they’re just a really flashy (and expensive) on / off switch, with very few strings to its bow.

BCO will want 1:60 ideally, or 1:80 if needed, but at 1:40 it may fail (if they give a shit that is). They're only really bothered about the ground and down / groundworks / manholes etc, and MAY ask about the SVP / AAV, but not many do tbh.

Any solar PV going into the existing hot water immersion? You’d lose that freebie if you jump to a combi. You’ll have to decide how much hot water you use, but there’s 2 adults and 4 kids (teens & upwards) here and I have a shitty Ariston combi I adopted and we have one bath & shower room plus utility, kitchen, cloak WC, and hot water is plenty survivable for us. If heating a big tank of hot water all the time for just 2 adults then a combi will likely suffice, and newer combis are much better at she flow rates, just get a min 28-30kW size and you’ll be fine. If PV, go unvented & system boiler for the free summer hot water.

👆. At 30+ years of age I’d replace any of the pipework that’s not 15mm or 22mm. “Microbore” needs cutting out if there’s any 8 or 10mm stuff in there. Keeping the backbone and any ‘embedded’ runs is fine, just needs to be flush properly, eg thoroughly, and then a good quality magnetic filter installed to stop any nasty residual crud getting into the new boiler. I’ve done these exact conversions so many times over the last 30 years that I must be in triple digits, so nothing to worry about at all, but the caveat is that you must accept that any pressure related failures will be on your head and not the plumbers; he’ll be connecting to pipework YOU own I’d say > 95% of the conversions done gave us no troubles whatsoever retaining at least some or indeed all of the existing pipe work (except the gas run which will defo need an upgrade).

Yup. They’re fine for internal use. The rest bends will make the flushed water much quieter, so I would do that if it was a job I was doing for a client. 👍. If it’s an SVP then obvs no need to an AAV 👌✔️.

+1. Have you allowed for air admittance, as this will be needed once the flushed water etc gets to the second vertical drop (eg at the outside branch)? Either that pipe extending up the outside wall to become an SVP or a stub-stack with and AAV on it if the former isn’t possible?

What say ‘yea about the detectors being mandatory in plant / equipment stores & spaces?