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The mathematics on this one is important. How much pipe surface is required to change the temprature of the air entering the pipe to exiting the pipe to signifcantly effect the building. It's a bit like a GSHP in that way. I think it's quite a length of pipe!

Hi and welcome to BH. If you and @Onoff had a baby, we would have developed the ultimate weapon. He wants to move out of his damp house into a new dry garage. Change your MX5 to a Capri and we'd be stuck to distinguish between you. Stick around, you'll be a great feather in the cap

If you plug an extension lead in somewhere and take it out to the light you can measure the resistance between the earth at the light and the earth in the extension socket and it should ideally be less than a couple of ohms. (Passing this test will also require your socket circuit earth to be present of course so two tests for the price of one!)

Which you can confirm with a multimeter

I'm "tapping into" the light above the front door, which is/will be rewire at the CU to its own RCBO. This circuit only (if the old labling is to be believed) was cupboard under stairs and outside lighting, where the only outside lighting is above the front door. As a side not if memory serves me from the old CU (rewirable fuses) the outside backdoor came from the "kitchen and back hallway" circuit- yes the old CU had about 3 pendant per circuit. Had a bad weekend of DIY where everything took longer and I dropped the light above the front door which damaged it (ceramic maybe), and upon inspection cracked slicing my finger. So confidence/ability has taken a knock. But thinking about it since my last post, if twin and earth is earthed at CU and there's an earth where the pendant is then by all purposes it should be earthed all way to CU...

Bit more done. Forgot to take a pic with the A142 mesh down and bit of 4" soil pipe set level (filled with EPS), in one corner for future electrics. Just glad the mixer wasn't petrol/diesel:

A diesel generator.

The DNO's system assumes that all you generate might be exported so they size to allow for that. So if you want more than 3.68kW then you need permission. Now your second battery charging system would be allowed as an off grid system if the items that the batteries powered were on a separate off grid circuit and there was no way the batteries could discharge into the grid. You could argue until you are blue in the face that you will not discharge the batteries into the grid and they will only be discharged when you have high power loads running, but they won't believe you unless you have a type approved "G98 relay" even if such a thing were available. I only have 4kWp of panels and have concluded batteries for this amount of power are not required, I can self use 95% of what I generate without.

Yes, but then integrating the battery storage into your home wiring may be a challenge. Yes, it is what diverters do, but it is still a grey area about allowing a larger than a nominal 4 kWp system be limited by the inverter (you can search for the thread about it, it is on here somewhere). Alternatively ask your DNO if you can connect a larger system. I don't have PV, but with batteries, it is all about load time shifting. It is similar to using E7. Now my E7 price has just gone up to 12p/kWh, so if the amortised cost is lower than that, then it is worthwhile. But you need to take into account what else you could have done with that cash i.e. put it towards an electric car, you will loose all of your capital either way, except the EV may have some value in a decades time.

Would it be possible to fit a 3.68kw system that could export to grid, and another 3.68kw system that just charged batteries? Or would it be possible to fit say a 6kw system, limit 3.68kw to grid, and fit a battery storage system for the remaining output? Do buildhub members find solar pv with battery storage offers a good return of investment over time? Thanks.

I'm sorry I don't still have the costings from my research. IIRC I contacted Rehau and they gave me the name of a design company who gave me the info I needed.

You can work it out. Surface area of pipe, thermal conductivity of pipe material, thickness of pipe material and the temperature differences. Just the same as working out the thermal losses through a wall or window. You may have to use a multiplier for the ground temperature depending on the soil type and moisture content. Use an indices if you want to get posh. 0 makes the number become 1, 1 keeps the number the same and anything greater than 1 makes it grow. I am not sure, after thinking about it for a decade or so, if mould is a problem. Decent filters (HEPA and activated charcoal) should be fitted, as well as insect and rodent barriers. Then just an annual sweep with a chimney sweep brush. So design cleaning in from the onset. Some sort of water drainage may also be needed.

This is what I built next to the front door. the middle section is a seat to sit on to put on your shoes.

Can you add some timbers for the overhang on the top of the roof joists so they line up with the top of the insulation, so 120mm insulation and 120mm overhand pieces? Then bring the wall finish up to meet them. You will need to insulate around the timber outrigger pieces.

There was lots of chat on this 10 years ago or so. iirc the consensus then was to use silver-lined pipes to avoid health issues related to mould growth. Not sure what the current thinking is, but do your research, it could be a breeding ground for mould.

It is the sanity checker for PV. East Anglia is pretty good for production.

Ideally you want batteries charged from the most productive modules i.e. south facing, optimal inclination. That will reduce the amount of modules needed and reduce the exporting of power. The East-West split PV systems 'to spread the load' can now be done from the batteries. Though batteries, on power delivery, are still limited by the inverter, and may not work too well with very small loads i.e. just lighting, assuming you only have a few watts of lighting on, not kW, like the olden days.

Have you checked the pre-charge with the accumulators empty, using the schrader valve? With 3 bar static, it should be 1.5 bar. You can't check it properly if the accumulator is full of water.

Losses are not too bad on the DC side, usually 4mm2 cable, so don't worry about that too much. Somewhere on here we discussed the 16A phase limit, and I can't remember what was the answer e.g. installed capacity or inverter capacity. Worth remembering that a 2 string inverter cannot take the full 3.6 kWp though one string, and strings cannot be too unbalanced. The manual will say what is possible. One way around it is to use micro-inverters and then run AC cabling back to the consumer unit.

I assume you mean to share one inverter between both arrays? The main constraint is the distance from array to inverter. This is high voltage DC cable, needs armouring if not left fully visible. Too long a run will cause losses, especially if it's on a short "string" of panels (which means lower delivered voltage, hence line voltage drop takes a greater proportion of the output). In general Voltage drop can be minimised by using thicker core cable, but MC4 connector limits how far you can increase PV cores. Ours is about 10m, from house roof to garage. What sort of distance are you thinking?

I cant recall as it's so long since I last looked into cedral but I thought the required ventilation gap was significantly more than the 10mm you mention - I have 50mm in my head, but I may be wrong! Just checked, it's 30mm behind planks.

Aerated blocks crack far too easily, move around and are naff in comparison to medium density blocks. No cracks is normal with them.

Don’t let the builder dictate how you want it done after you have researched it, cause 90% of the time his method will be a shortcut to save him time, effort or materials or a combination of all 3. At work I insist that walls/floors are inspected prior to a covering/plasterboard being applied to ensure no shortcuts.

As long as the new DPM laps the DPC it will be OK but needs to be protected against damage. Is the Topflow Horizontal expensive? I would be interested to hear how the pour goes / any photos.

Go and have another conversation with the twat and record it. Post all over FB if he wants to play dirty and vindictive.

How will you stop air and wind from outside, in the loft and in the floor void from blowing around behind the linings? if it does this then the insulation value of the protherm will be partly or totally lost don't underestimate how difficult it is to keep draughts out, lots of people get then coming out of socket outlets even on internal walls, under skirtings etc

Thanks again for the indirect mention

Welcome. Ask as many questions as you like. I like to think that the people on this forum are a very smart bunch of folks, with a bit of fun added in for good measure. However, be wary of people trying to sell you walk on glazing. Unless you actually need some, in which case we have just the chap.

It is clear there are no seriously overweight people in your house! ?

Ok, here goes. A bit of context first. Ferdi refers to a wedgie above That may well be about my efforts at putting in joists. I was doing soooo well, and then this happened .... With a bit of luck that should send a sip of tea through yer nostrils ...