Nickfromwales

Far left (non lollypopped?) is a 22mm feed to a 3/4” 2-port manifold, with 2x 15mm outlets, ergo the sum of the output cannot ever exceed the sum of the input, or words to that effect. When you get to the 7-way then the maths change; if you squint a bit you’ll see this gets fed from 28mm vs the 22mm used for the 2 and 3 port manifolds. Just some simple plumbers maths, nothing more. The 3-port is the hot return with 10mm pipes, so just a crawl there. You’ll notice that there’s 2x TMV’s immediately off the 28mm hot outlet of the UVC. Left one (22mm) feeds the kitchen and utility sinks @50°C, and the right one (28mm) feeds all sinks, bath, showers at 45°C. As this is Hep2o and there have been ‘issues’ with using it for hot return, I follow their guidelines and a) time the HRC so it’s not ‘on constant’, and b) temper the water in that loop so it’s not ever at the terminal temp of the UVC; that can be north of 70°C if solar PV excess or cheap rate electricity is fed into the immersion, plus the 45°C flow temp of the HRC means much lower losses too. 👌. Again, it’s down to dynamics of the particular site, but at 5 ports (and the assumption that some were basins) I’d have said it’s fine on 1x 22mm feed from one side. Bath and shower outlets seem to feed at roughly the same rate, as EU compliant and low water consumption outlets are commonplace nowadays, so no need to worry about huge flow rates to a very big bath for eg (unless you actually have one, and then the conversation would change) . Then, and then alone, I’d say have that closest to the feed end, but prob arguing over pocket change there tbh as the manifolds are 3/4” bore which is quite decent. Oh, if only you hadn’t said that bit, I could have stuck to a simple reply lol. 😌 So, for ”The science bit”…..(please manage your expectations here). Dynamic flow rates at the incoming cold mains will affect how I ultimately ’plumb things’, but I also respect my clients enough to give them a minimum expected level of GAF, so, then the ‘problem’ and the solution become more relevant (and apparent, hence what you’ve seen and the question it has provoked); at which point I will assume a responsibility to provide a solution that is engineered to yield the best possible results, for the given circumstances, as the minimum standard. For the 7-port manifold, 28mm flow is then divided at a 28mm tee (22x22x28c) into 2x 22mm feeds to each end of the 7-way (port) manifold so ‘theoretically’ 3.5 ports each get fed from 22mm feeds, a-la an electrical socket outlet in a ring main. ”Couldn’t I just feed one end of that manifold with a 28x3/4 feed?”, you may ask. Yes you could, in reality, more-so when the cold mains is much better for eg, but when the house is occupied, all rooms in use, bathrooms a-blazing’, the ‘solution’ comes into play because the setups I design / deliver can cope under duress, admirably, with one hand tied behind its back. Would someone get upset if 3 showers didn’t work simultaneously, and if they did, albeit poorly, would they accept that they could only be hot for <10 minutes each before going cool then cold? Yes, they’d be quite upset that the brand new 6 or 7-figure home they’d just spent their life savings on failed to perform when it was occasionally at capacity. It would be a bit of a ballache at the least, borderline embarrassing at the worst, have to schedule your guests bathing methinks, but there are plenty of folk out there who would say that’s “fine”….I’m not one of them obvs 🙄👎. I don’t design systems and install stuff to be “OK”, there are plenty of people churning out that level of crap, and I don’t fit a 2 person setup in a 5 bed / 3 en-suite / 1 family bathroom home; (caveat: unless I am directly told to do so and I’ve covered my arse against recourse by getting that in writing). Chinese Confucius say…”you can turn a big system down, but you can’t turn a small system up, grasshopper”. 🙏 I install stuff to suit the size and capacity of the dwelling and I don’t deviate far from that, ever, as that services nobody’s interests well; my ethos is plumb to suit the capacity of the house and the worst case, and then nobody will ever be disappointed. For the above project I also installed a 300L cold mains accumulator as the owner reported mass local development and the loss of 1bar of pressure over the last ~2 years! That’s also why all the cold mains and primary stuff is done in 28mm / 1” BSP, including the 1”/28mm large-bore flexis used to connect to the high flow water softener. And so on…. Amen.

Their website has projects & testimonials iirc. I’m really becoming a fan of this idea, as the cost of tape and the time and labour to do that, plus trying to (find and) fill the nooks and crannies is a major ballache. When you get the job done please do come back and let us know the results, warts ‘n all! 🙏

Stick to your guns.

Makes your fecking knees hurt!!!!!

Come doomsday, it’ll be the only thing that’s still working mate!

I spoke to a rep(?) at AB about a woodcrete ICF job for a member on here and they say it’s just done on m2 vs the substrate so it should matter with block tbh. They just asked that you prep it as well as possible, carry out 1st fix, and they state that they will then make a ‘good’ job ‘great’.

I’m lazy, what can I say lol? 🤷‍♂️🤦‍♂️

Wouldn't that have to be from a 'synthetic' metronome that they all listen to?

It's nuts tbh, we're in chuffing 2025 and they can't keep the lights on!?!

I've not got any direct experience with Victron, but unless you have optimisers you cannot find a dead panel without checking each one. We've installed systems with optimisers (Tigo) for yonks without any issues whatsoever, quite the opposite tbh.

Well, the spinny round bits are certainly not sat still! lol. 🤷‍♂️🤦‍♂️

Have a look at the Aerobarrier system. https://www.aerobarrieruk.co.uk/ Cheaper and better than you think. They say if you just foam the windows and cut it flush they can take over from there. Speak to them and get a quote / do the maths, I think you'll be pleasantly surprised. Certainly an option, and a 1 day sitting and they're done.

Just fit optimisers if you want to be able to narrow down finding a duff panel. Or fit panels that simply live, nearly, forever. 🇩🇪

Reverse / inverted / snail, all called different things by different folk, just where the pipe isn't serpentine; eg it's not just simple up / down / up / down runs with 180o loops at each end. This is easy to implement when pipes are at 150-200mm oc, but at 100mm it's nigh-on impossible to do anything other than inverted.

Mine is the truth and the light….. etc etc But some horses do refuse to drink lol. 🤷‍♂️🙃

We’re just filling our boots, no need to ‘go there’ . You must go the distance with your SE, obvs, but if there’s any threat of an earthquake I’m coming to stay with you 🙂

I’ll read that to the kids before bedtime. They’ll be confused but fascinated lol. 👌 👆👉💪😊

Especially when the ring and intermediate beams are doing the majority of the work. 175mm is over egged for a domestic residence as the slabs then distribute weight over the area so benefits become nigh on inconsequential over 100mm imho. 280mm for a previous job, and then the guy wanted to put UFH on top in a screed FFS. In a 1.5 story house!! I challenged, with reason, and they reduced to 230mm(!!) iirc, but agreed also to then lift the slab, inset the UFH pipes, and feck the screed off. Saved the client 5 figures in 2 sentences. And I was late to the meeting lol.

Indeed. There’s just not enough difference to go and beat the crap out of a tiny HP. Then it’s far more justifiable for a small HP. If you steer away from this then seriously consider a 5kW HP to get headroom for DHW production.

Unvented hot water cylinder.

Odd, but not a life changing issue. The only reason to wrap this pipe is if your intended concrete work is going to come into contact with it, or encapsulate it.

I’d install a bigger UVC and plan a cheeky 2-3hr hour top up via the immersion heater(s), timing this to happen for the last 2 hour window of cheap rate nighttime juice, a-la Octopus, so you’ve got a good supply of DHW for the morning shower runs etc. This would be a winter strategy btw, but assuming solar and a base temp assumed at 50-55°C when heated off the HP, then having higher capacity can only be a benefit here as you’ll have more energy stored in the same size cylinder when heating via the immersion. Add PV and topping up the DHW at midday for the evening (at a time where an hour or two of HP > DHW won’t effect anything / anyone, this is win win. I’d try to keep the HP away from doing DHW overnight, ever, during winter, especially with such a lack of headroom with a 3.5kW unit. When you do the sums and include defrost and the expedited demise of the HP it makes more sense to use cheap electricity directly (near 100% efficiency) via the immersion when running the HP just doesn’t make sense.

Anti convection loop would have to go between the UVC and the manifold. But it doesn’t matter because you’re not going to install one……..😉🤝

Not that I ever throw any spanner’s into any works…… ……actually I’d think this through before making a bad choice . In that pic you’ll see I’ve provoked (intentionally) this exact thing to happen, as with the last setup I did, and it’s how I will plumb the next, and the next. Short lived will be your cunning and planned celebrations of the joys of foreseeing this ‘terrible loss of heat’, and the use of 10mm pipe to get your DHW swifter than a swift flying during a hurricane, as it’ll go tits up the second you do your anti-gravity / convention loop. All the wasted (and useless) water volume held in that plus the fact it’ll either be 28 or 22mm pipe, will instantly negate all this as you’ll prob have longer to wait than if you’d run the feeds in 15mm. By the time you get the dead leg out of the primary larger bore pipework and then premium (useful temp) DHW out of the average outlet you’ll be sadder than Mr.Bean when he lost his teddy bear as you will then realise it was the wrong choice to set it up this way. The ACTUAL annual costs (perceived savings of stopping heat wicking up the pipework) would need to include the wasted cold mains water that you then draw off as useless dead leg, then you’re very much into the price of a decent meal for 2, in ACTUAL reality. Then factor in that this primary DHW pipework will be well insulated plus the sobering reality that this aforementioned ‘runaway convection’ just won’t happen, (as you refer to with the open pipe / vent of yesteryear (which is entirely misleading and utterly irrelevant here btw!)), and then you place a cherry on top. The cherry is, that with the large bore primary pipework already preheated by (local) heat wicking up it from the UVC, this then cancels out the delays caused by lengthening the pipework between the UVC and the hot manifold; viola! The result you want from this is for the pipework from the UVC to the hot manifold, AND the hot manifold itself to be warm / hot as the default; insulated to stop latent losses as best as is practicable. THEN, my dear Watson, your plan of using the 10mm feeds will be one of genius, but more importantly will then actually bear some fruit. Convection (runaway) can’t happened here as there needs to be an unobstructed path from hot > cold to create a convection loop, as your taps / outlets will be closed, the case for this is closed. Use this ‘problem’ to your advantage squire .

@Egnaro If it’s Terram / weed barrier it’s in an odd place but should be inconsequential in terms of what you’re doing. Weed barrier is usually to do exactly that when landscaping, eg stop organics from growing. Somebody may have put this over the pipe as a marker, just a bit odd due to how close it is to the pipe. If it’s all backfilled with concrete then you’ll get the same effect, but you should wrap the pipe of concrete will be meeting / encompassing it, to allow movement.