-rick-

Solar is 1000W/m2. Work out how many m2 of the planet there is and calculate the total amount of energy (obv not all planet is exposed to sun at same times). I'm sure an AI will help do this. Then calulate the amount of energy we put out. It's a very very tiny fraction of total energy. Haha here comes the jetsons! No, not gonna be in cars any time soon (or trucks). Batteries are perfectly fine for those. Ships, and only very big ships, there are are really two options to power them that don't burn vast quantities of fuel. 1. Sail 2. Nuclear Some ships are trying out sail and modern systems are aimed at reducing fuel burn not eliminating it. A useful contribution but not game changing. Ships have a schedule to keep so can't be waiting around for the right wind conditions. Nuclear on those ships is not crazy. They already have largeish crews with dedicated specialist engineers on board. The type of nuclear talked about for those ships is the 60-100MW range, so tiny comparitively. Likely to be an inherently safe design that is packaged as a module and craned on/off for maintenance, etc.

Firstly, I think we are talking about renewable in the sense of 'planet earth has limited supplies'. Once we go off planet the resources available are vast (but the technology required to access them are also a long way off). If we are just worried about planet earth then the available resources for nuclear is more than enough to keep us going for a very long time without worrying about depletion. If nuclear was cheap and we had well developed end-of-life plans I don't see much issue with it given current safety standards. But it's not cheap and we don't have well developed end of life plans so I'm not a huge fan based on that. Having said that, if the safety aspect can be dealt with putting small nuclear on very big ships would eliminate a lot of emissions and potentially lower costs for everyone. Using nuclear generation produces heat and some have questioned whether that heat output is a negative given global warming. My understanding is that the amount of energy used/heat produced by human activity is absolutely tiny compared to the amount of heat/energy output into planet earth from the sun and it's therefore not remotely a concern. Maybe a concern in local areas (heating seawater locally, producing fog in local valleys, etc). But these are the same as any other steam using power source (gas, coal, wood, etc).

If both pipes are close to each other and there's been ground movement it would make sense for both to be damaged. Hopefully this narrows down the search area to only those where the two pipes are close to each other?

Not important but I have absolutely no idea what you are getting at here. 🙃

Check this asap. Expensive problem if left. If meter is spinning, turn off at meter and see if leak stops. (If you are not on meter isolate at external stop-cock anyway to check flow) If meter not spinning, then likely coming from another house. Report as leak to water provider and let them trace it?

How about invest your money (and mental effort) in buying a wireless charger/battery like this*: https://www.amazon.co.uk/Anker-Magnetic-Wireless-Portable-Skin-Friendly/dp/B0DCNKDS5B?sr=8-4&th=1 Plan to charge overnight, if you forget you can get this out of a drawer and stick your phone on top. No wires. Then when it's done plug the powerbank into recharge somewhere out of the way ready for next time. Job done move on to next one. * Anker is a fairly good brand but I have no personal recommendation, this was just the first search engine result

There are two ratings on an MPPT for current. One is the maximum current it can usefully convert, the other is the max short circuit current. As long as your arrays in parallel stay below the max short circuit current then the effect of having more generation capacity on one MPPT than it can handle just limits the maximum energy you can generate. On an East/West (or North/South) array it's very unlikely both sides will be operating near maximum at the same time and for the few hours per year they do its not necessarily worth the cost of another MPPT. Solar panels are so cheap compared to everything else that it's often worth maxing them out to increase generation outside peak/during winter at the expense of not being able to use all generated energy in peak summer.

Well this thread drifted. I'm just catching up after being away and nobody appears to have mentioned that each 3600W oven likely requires 16A protection in the CU not 32A. Check the manual. Normally the CU protection is there for just the cable, but for wired in appliances I think it also needs to be sized to protect the appliance. (TBC I'm not an electrician so check this with someone who is).

I vaguely remember seeing something about less potential cold drafts when showering if the fan is not directly above.

indeed. I try not to assume but when I do it often comes back to bite me. im not the best person to ask but i believe yes. But if you’ve got a plumber who will always install cheapest available option then you may want to put some effort into specifying better quality valves (or expect leaks at some point).

What did you specify/agree to for this installation? Has he put isolators at the other end? That would be what I’d imagine an uncreative plumber not used to installing manifolds would do. (afaik isolators somewhere are a requirement, exact location isn’t) I don’t see the logic in doing it that way. You want a way to isolate leaks. Best place to do that is at the branch point of the circuit (*). Gonna be a pain in future if you want to change things as is. So I would put my foot down in your position and have them fitted at the manifold. * whether you want a second isolator at the end of the pipe is a question. If they are already there I don’t think I’d bother removing them. My experience with isolators is that they have leaked more than I’ve needed to use them as isolators, so I think I’d be inclined not to duplicate. Though from reading here it sounds like the leak issues are common with cheapo/screwfix type isolators. Higher quality ones are good.

and this is not just making a joke. It’s likely that the training corpus for the llms has the best responses in relation to professionals who don’t tend to use that language. By swearing at it you likely trigger different statistical paths within the training that have less optimal outcomes.

maybe swearing at a computer program isn’t the most effective tactic

I think you’ve missed a key part of the specification which is to keep @Pocster occupied and provide an easy distraction from finishing his house. Everything following that is just part of the journey. 😜

sure, but yet if you look at what’s offered commercially as solutions to insulated rafts. You have some companies (eg kore) offering standard starting points of 100mm slabs with thickened sections and relatively limited rebar vs isoquick with 250mm single thickness slabs with tons of rebar. Afaik for equivalent ground conditions. Now it may well be that isoquick is designed to allow for a more diverse range of ground conditions ‘off the shelf’ vs kore that would get bulkier in some. But if you go with isoquick for ground conditions that work with the standard kore then you’ve used significantly more concrete and steel for the same (and labour to install the rebar) than kore. absolutely interesting point. Noted agreed. One of the reasons I lean towards paying others to get to level slab and doing much more myself after that point. Yep. Seems like the easiest way to get in a mess with building projects is to design as you go/start with rough detail and plan to flesh out as you get to each stage. Unfortunately seems like an all to common approach for people.

good idea. Cheap enough that you could buy now to trial before you spend money on plumbing the house.

hopefully someone has the time to do the maths or get Ai to do it. But my guess is that water at 15-16C has nowhere near enough potential cooling in it to strip the humidity out of incoming humid air before the MHVR. (Dehumidifying humid air uses a similar amount of energy to cooling it). The MHVR can do effective bulk dehumidification but only to a limit. So my thought is let it do that for free then use the coils to take a bit more off the top once the MHVR has done as much as it can.

Agree with that thought. let the mhvr do the bulk to the dehumidification for free. The coil just does the top off. It means the temp difference between the water and air will be lower so less effective. But there’s no way near dew point water will be able to suck much out of the air but even a small amount might be enough.

I think it’s well established that a hydronic heat exchanger in line with the MHVR doesn’t really have the oomph for real heating and cooling. I’d always thought to add a smallish one anyway with the hope of maybe bringing the mhvr output air temp above/below* the ambient internal temp vs just below/above* due to mhvr efficiency. Thinking being that not every room would be exposed to ufh so the mhvr coil would just help distribute the heat/cool more widely (Wouldn’t even think about it if couldn’t find a suitable cheap coil) This thread has made me wonder if that coil might have a useful dehumidifier aspect during heatwaves like this. If you are running the flow temp low enough to cause condensation on the floor then inevitably the exposed coils in the heat exchanger would be cooler than the floor and attract more condensation. If running only a touch below dew point then maybe the excess moisture preferentially condenses in the mhvr coil and prevents condensate forming on the floors. So not full bore dehumidification but just enough to allow you to lower the floor temp a degree or two more than you otherwise would. Does this stand up to reality? * depending on whether you are heating or cooling (in that order)

Depends on your unit. They can be between 60 and 90% efficient. 33-24 = 9 9 x 0.1 = 0.9 0.9 + 24 = 24.9 incoming temp in the 90% efficient case? (not 100% sure I've done this right but you get the idea). The air from outside will inevitably be warmer than the inside air in this situation, but would be much less warm than just opening the windows and blowing the outside air in.

Definitely an important point (which was the caveat in my previous statement though not expressed as such). I'm always thinking about keeping the details to something I would be able to do myself. If/when it comes to the build I don't intend to do everything (though a substantial part) but by keeping that in mind I want to keep the options open depending on contractors and skills available when it comes to it. Having said that, laying UFH is very DIYable and likely to lead to a better result than an uncaring contractor. Installing rebar on the other hand is more challenging and have a contractor come in with lots of heavy rebar after the UFH is laid would be a reason not to do it that way. This is a good point, I've tended to lean the other way (less concrete/rebar if possible) in order to keep the embedded carbon down. Though a thicker simpler slab is likely easier.

AFAIK the concern is mainly structural damage caused by damp. But also a concern that a damp area might be make a good home for mould. Short term none. Long term, maybe there's more condensation that you don't see that will cause damage given enough time.

It's maybe not the most efficient way to organise things, but only really needed for extended heatwaves. Reducing the humidity will definitely affect how it feels, but also lower the dew point that would allow you to drop the water temp running through the floor without worrying about condensation, so you could get more cooling from that system. Time to insulate those pipes! Waste of money heating/cooling the loft.

This has been quite commonly done by people on this forum building highly insulated homes. Idea being you design the home to be a stable temperature and the slow response can be used to your advantage by loading in the heat when it's cheapest and letting the floor buffer the output over the day. Putting coils anywhere in a 150mm+ slab is not going to lead to a fast response anyway (need a insulated screed for that) so burying the pipes lower also minimises the chance of damage later and debatably is easier to install. I can't remember all the arguments for this method made by others off-hand, but do know that after reading thoroughly here I'd been persuaded that I'd likely go that way if/when I come do this. (dependent on installation sequencing).

A dehumidifier could do the same job and they are pretty cheap. Wouldn't the ERV help even in these conditions, slowing the rise of humidity caused by outside air vs a HRV which would just dump all that humidity straight inside?