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No comment milud. actually it was a blind date set up by our friends, her first question was "what do you want to do with your life", I said retire and build my cottage in the countryside and I don't care where." I asked her what she wanted to do with her life and she replied " I want to retire to where I come from, Devon, and I just happen to own my late fathers old timber and asbestos bungalow out in the sticks down there", ( and flattering her long eyelashes said) "but I don't have the resources to do it up or anything". Kerching ? ( not a bad cook)

Hi Ted. Welcome to the site. I wish you luck and a future MRiCS, but to be honest this won't go anywhere. My attitude to the 2020 EU nearly Zero Energy Buildings Directive as a context for UK self-build homes, is that it is not a context for UK self-build homes because we are leaving the EU in 2019. No one - whether self-builders or construction companies - will spend any time on it. And having gone through the last Zero Energy Buildings Initiative as wished on us by Mr Blair and Mr Brown, which imo was a bit of a dogs' breakfast requiring a scattergun of ideas wished on us by an out of touch Government relying far too heavily on technical gimmicks rather than quality building, I am glad that it is not coming here. The only possible bit of context I can see left is for people importing their kit homes from the EU. Is it possible for you to refocus your project on something that is actually going to happen? For your interest in energy saving there is potential in: 1 - comparing self-build standrds with corporate build. What difference and why? 2 - perhaps perceptions of why individuals feel a need to import "low energy" kit homes rather than build them here. 3 - related to 2, my suspicion is that far too much money is being spent on expensive solutions that happen to have particular country labels on them ,which is a success for Brands over knowledge. There may also be something about a related lack of clear information concerning the UK industry and what is available. 4 - Jeremy's point above about the proliferation of planning and compliance costs is an area that needs work. Could you reframe your project around barriers to achieving high energy efficiency for self-builders and corporates? One angle would be the massive increase in people and bodies who have a right to be consulted in a Planning Application over the last 2-3 decades (this is one of my hobbyhorses). 5 - Exploring the enforcement of building regs standards and declared designs in what is actually built. This is a Jeremy area of interest, but your target audience would probably need to be Building Standards Officers in Planning Authorities as the enforcer, and corporate builders, and self-builders. I think you need a rather sharper focus, and perhaps a project redefinition if it was set up before June 23rd 2016. I am sure that people here would be willing to spend a little time on advising you publicly or privately. There are also people here who could introduce you to the right industry people to interview. Hope that helps a little. Ferdinand

Nah, just what I say when I start the day in 'clean' clothes, and then have to go back home to chuck the boots and combats back on Well, before this got to a point where we assumed anything, and then you acted upon it, I thought it best to chat briefly with the tech guys at Telford to see what can actually be extracted from a X sized buffer tank with regards to DHW uplift via an instantaneous coil of X size. Bigger of both = more and vice versa. So....after a chat and a brew....deep breath...."options" :- On the assumption that, You already will have an ashp installed and working. You already will have a buffer of whatever size installed, according to majority advice and positive feedback here ( against running a HP to Ufh directly in a 'low' energy home ). You will have a reasonably sized Pv array. I have arrived at the following :- The costs of the larger buffer tank, having it fitted with a 4.5m2 DHW uplift coil ( the minimum size that would offer any meaningful yield at low temp but also physically too big to go into any less than a 300L cylinder ), accepting a reduced max flow rate of 18litres per min, ( you may well only have 18litres per min coming in so case specific for that point ), and the additional volume of antifreeze ( plus replacment of the antifreeze every 5 years as it has a limited working life ), make the TS and coil option for DHW uplift very tight, if not plain uneconomical for your expected DHW needs. So, after more head scratching, further tea drinking and procrastinating..... The figures do stack up quite well in favour of going for a small buffer and copying @JSHarris with a plate heat exchanger, but as your expected DHW consumption and flow rates may well be double his, I'd suggest going for a pair of 30kw versions running in parallel to get a combined pipe size input & output of 22mm ( to match the UVC accordingly ). PHE example only PHE's are far better at transferring heat from a wet source than coils, especially when being used at lower temps. I've had to adjust my thinking accordingly for this case, and even so, I still think it's a worthwhile endeavour. Less long term labour of the ASHP = longer life expectancy. Far fewer defrost cycles compared to driving DHW directly from the ASHP at high temp range. Majority of the DHW getting produced at the better CoP rate, ( DHW will be your biggest energy requirement as its needed year round eg also when you have little or no Pv gain ). Smaller buffer tank ( circa 100 litres ) with less loss, size, and reduced antifreeze required. ( thanks @Alphonsox for the example costs, makes it a game changer tbh ). So, to summarise, I'm still thinking of DHW uplift from the ASHP via a buffer, but a smaller buffer and PHE's instead of the coil. That will require a pump and flow switch, ( any PHE will need one ). Still relatively straightforward tbh, and may just provoke me into getting off my arse and looking for a decent plumbing schematic software so I can translate this babble into a working drawing for a / your plumber to follow. Thats the chat I've just had. These cylinders have very low heat transfer rates at low temp, so that type of cylinder would need to be VERY hot in order to do what is suggested in that image . It would also need to be KEPT very hot to do it too .

You've got to ask the price every time at builders merchants, other wise you get ripped off!

I think it does for a lot of Chinese stuff, far more of it just ignores the safety regulations then most people realise. Years ago I had a friend who had a business making custom bicycles and he imported almost all his components from either China or Taiwan. He went to Shenzhen in China to meet some suppliers, and sent me some photos of his trip. He spent half a day in one of the massive emporiums there, and one of the photos was of a stall that only sold stickers with things like fake CE marks, Windows and Apple logos, etc. I remember him telling me that it was very difficult for a small business to get manufacturers in China to adhere to any sort of standards, as they always want to try and reduce the cost by cutting corners. He gave up with getting components from China in the end, having experienced non-existent adherence to specifications, and now buys only from Taiwan, where it seem that manufacturers understand the need to stick to an agreed specification.

The electrician that has installed/signed off your installation should have made sure that not only was there a proper earthing scheme fitted, but that it had been tested and was compliant with the regs. AFAIK, being off-grid doesn't exempt anyone from the regs - if the system is above 50V AC then it is an LV installation and the regs apply as they would for a grid connected system. For a generator or inverter powered 230 VAC system the requirements are that a local protective earth should be provided, in the same way as would be the case for a grid supply with no protective earth. The 230 VAC connection from the inverter should be connected via a suitably rated fused double pole isolator to the consumer unit, with the protective earth being provided by a TT system. This means fitting an earth rod, testing Ze to make sure it's within spec (no greater than 0.8 ohms normally) and using that as the protective earth for the installation. The consumer unit, or other distribution point, must have a double pole RCD or RCBO. The inverter you have looks to me as if it's a Chinese made unit, as it's marked 220V, yet it carries an EU CE mark, which is odd as the EU supply voltage standard is 230 VAC, not 220 VAC. Fake CE marking is extremely common, so common that I suspect there are more fake marks around than genuine ones. That doesn't mean the unit is inherently unsafe, although as it has a metal case and makes no mention of earthing one has to be just a bit suspicious. The case should be earthed, but it would be wise to check that the output is really isolated from the case before doing this. An electrician could test this in a few minutes, easily enough. Finally, there is usually an insurance requirement that any temporary LV supply (and LV is anything over 50 VAC and under 1000 VAC) should be installed, tested and signed off by a competent person. Even if an insurer doesn't require this, then it still important that it be done, particularly if a third party, like a contractor, is working on the house. Failure to have a properly installed and tested LV electrical installation, even a portable site system, could make you personally liable in the event of an accident. Edited to add: Looking more closely at the photos of that inverter, I can't see any shutters on the outlet. Well worth checking this, as a properly approved BS1363 outlet must have an earth-pin operated pair of shutters that close off the line and neutral sockets. If it's as I think, without shutters, then the CE mark will definitely be fake and it would be advisable to do some testing to make sure that it has adequate internal insulation and isolation between both the DC input terminals and the output terminals, and between the output terminals and the case. For use as a temporary, perhaps portable, supply then I'd suggest that the minimum requirement should be a decent earth rod and connecting conductor connected to the inverter earth, together with a plug-in RCD to provide protection to any user. Edited again to add: The seller gives a valid GB VAT number, but this traces to this flat: Member State GB VAT Number GB 243079218 Date when request received 2017/03/24 10:54:40 Name JUNFENG CAO Address FLAT 93, ADDY HOUSE ROTHERHITHE NEW ROAD LONDON SE16 2PD

I've now got 15 cheap Chinese ones. I'll buy some from Darnell and compare them in my test rig. I've been buying the waterproof ones - partly because the probe packaging with lead is far more robust. The cooling cup of water is a good way to check.

The local planning process?

If anyone is interested, then I can post design and assembly details, esp8266 code or links to it, etc.

They look pretty good and amazing for the price. I use various 3D drawing packages and Photoshop every day as an architect but couldn't compete with that price. Even if you get some poor student in college learning the program you won't beat that price. Great value.

Yup, I'm in

Guilty?

Brief (and belated) update. After much deliberation, we've finally ordered a staircase. Had several quotes in the £5.5k to £6.5k range for oak stairs similar to the one I linked to in the first post, but decided we'd really like something more contemporary (even if it meant spending a bit more). Ours will be styled as per the one in the image below, albeit with a double winder. Lead time is 8 to 9 weeks but will hopefully be worth the wait

Well I designed our build over 20 years ago ( in my head) and it was not until I met my wife ( who had a plot with an old knackered bungalow on it) that I had somewhere to build, we just turned it round 90' luckily my wife liked the design, we both love cottages and it's the Devon countryside. What's not to like!

There shouldn't be any capacitors on the AC side of the inverter, but with no protective earth (!) the earth conductor won't be doing anything useful. With a DC to AC inverter (or generator) you must provide a protective earth with an earth rod or other connection to a known to be good protective earth conductor, to make the installation safe. The installation should be wired in a similar way to a TT mains supply system, with a tested and known to be OK earth rod providing the protective earth at the supply end, in this case the inverter AC output side. In theory a floating supply "could" be safe, as long as there is no possibility whatsoever of an incidental connection, or leakage path, that could mean that the inverter AC output terminals are referenced to local earth. Frankly I would NEVER want to go near a non-earthed installation like this, though. I know people often completely ignore the instructions to provide a protective earth when running generators - that does not make it safe. (The above photo is a joke, before someone makes any comment about it........................)

Shouldn't we touch on the waterproof "exterior" and the more general (and cheaper) everyday versions of PVA? Big difference in price. I know back when I temporarily dust proofed my concrete floor in the bathroom I used dilute SBR bonding agent on advice here rather than PVA. This on the basis that when tiling later there's a risk of water getting under the tiles and affecting normal PVA. It was cheaper using SBR than buying exterior PVA. I do know some on here have dust proofed say their new garage floors with dilute PVA. I've certainly glued T&G chipboard flooring together with it. I'll often use it when doing noggins before I screw them in. Doing it throughout boxing in in my bathroom. I've used it btw when the kids have run out of "craft glue" and topped the bottle up. Made many a paper mache'd balloon head when they were younger!