Jeremy Harris

I've put a deposit down on a VW ID.3...

The Munster Aluclad range have a foamed uPVC core, with aluminium on the outside and timber on the inside: http://www.munsterjoinery.co.uk/ PITA to deal with, though. They are good value, but being so big, they aren't really interested in dealing with self-builders.

The history so far shows that no EVs have needed replacement batteries as a consequence of normal wear and tear. I believe that some Tesla's are well over 100,000 miles and still absolutely fine, and arguably Tesla's don't have the best battery chemistry for a high cycle life, as the pack chemistry was really optimised for high performance. As a rough guide, the cycle life to about a 30% capacity reduction is around 2000 cycles. Taking my car as an example, it has a nominal range of 120 miles (in reality I get around 140 miles). It's done around 95 charge cycles so far (a fair few of those have been zero CO2). At a guess I'd say it will perhaps use maybe 150 charge cycles per year, probably less. 2000 cycles would be a life of around 13 years to a 30% reduction in capacity. At 13 years old the car most probably isn't worth enough to warrant replacing the battery pack, but a pack with 70% of it's capacity remaining would still be very useful for something like home battery storage.

Usual Top Gear claptrap, I'm afraid. A friend of mine has a 2013 Leaf and it still does pretty much the same range now as it did when new. My BMW i3 has now done a bit over 12,000 miles and is still delivering about 20 miles more than the specified range, and shows no sign of the range decreasing at all. Same goes for a friend who has a three year old Tesla, it seem to have pretty much the same range as it did when new. My 5 year old Prius Plug-In that had done around 50,000 miles when I traded it in was still delivering exactly the same battery range as it did when it was new.

TBH, I can't see any reason not to DIY piles, especially pretty foolproof ones like screw piles. When I looked into using them it seemed to require little skill, just a matter of driving them until the right torque/depth was reached. I watched a few videos showing screw piles being driven and it really didn't look to be that hard a job. Not sure about other types of pile, as I didn't look at using them (screw piles were needed for the first plot we looked at because of the need to minimise damage to some underlying archaeology).

It was a lot cheaper than I expected, too! The spec says it will pull down to 3 Pa to 5 Pa, which should be fine. It's a fairly standard single stage rotary vane pump, running in an oil bath, so not much to go wrong, really. The main downside is that it's only 1/4hp, so will be a bit slow to pump the system down. As this is a DIY job on a small system I doubt it will be an issue, plus I'm in no hurry, so a few minutes longer to pump the system down is neither here nor there.

@jimbob1, I've just deleted the duplicate thread to keep everything in one place in this thread.

I've managed to get hold of the installation manual, which seems pretty straightforward. The unit is pre-gassed for up to 10m of pipe, and I'll be using 4m, so that's well within limits. The plan is to connect up the pipework, vac it out using the service port and make sure it holds for 15 to 30 minutes, and, if all is well, open one of the outdoor unit valves to pressurise the pipe work, then close it and leak test all the connections. If that looks OK I'll then open both outdoor unit valves and finish the commissioning. Main thing to watch seems to be the risk of getting an inadvertent cold burn from leaking refrigerant (I'll wear gloves) and the possible fire risk from leaking refrigerant (pretty low risk outdoors, but I need to ventilate if I get an indoor leak). I've looked at vehicle vac pumps and gauges, but they seem to use different pipe connections to domestic units. Not sure why, but gauge sets intended for vehicle use come with adapters, so cost more. I've ended up buying a vacuum pump and set of gauges and hoses for less than £70 delivered, which is way cheaper than the ~£500 to get someone out to install the unit, and less than half the price of just getting someone out to gas and leak test the system. Seems wasteful to buy kit that may only be used once, but if that's the cheapest way to do it then it makes sense. May come in handy if I ever have to do any work on the system in future, perhaps. It seems that cans of refrigerant can be bought for around £30, so now I have the kit it should be possible to re-gas the system if it ever needs it (not strictly legal, as it needs an F gas ticket, but it seems that there are lots of people around who are ignoring this).

I do hope not. When I was talking to their technical chap, back when we bought the Sunamp PV, the life of the unit was being estimated at around 20 years +, based on the accelerated ageing testing on the PCM they were doing. I'm not sure what they are quoting for the UniQ range though...

I've opted for a Toshiba Mirai RAS-10BKVG-E, 2.5 kW, 9,000Btu unit in the end. Bit of a palaver ordering all the right bits, but the total for everything, including 4m pre-made up pipes, trunking, cable and both a vacuum pump and set of manifold gauges, has come to about £750. That's £500 less than the price I was quoted for a no-name Chinese unit installed. The warranty is a problem, as by opting for a DIY install I'll lose the Toshiba warranty, but, on balance, I think that's worth taking a risk on. If it all goes tits-up I can always get an F gas chap out to re-gas and leak test it for less than £300, so it's still a saving on having it professionally installed. The reasons for opting for the Toshiba, rather than the Mitsubishi were mainly to do with the best deal I could get, plus the much lighter weight of the Toshiba outside unit (23kg). As I will be wall mounting the outside unit, quite high on the wall, weight was a significant consideration. Another consideration was the illumination from the inside unit display. Several systems I looked at had bright displays on the indoor unit, which may have been a nuisance in a bedroom. Assuming all goes well, then when I've finished I'll have a vacuum pump and gauge set available for others to use. It seems better to use a vacuum pump, both for leak testing and, more importantly, to get any residual water out of the pipework, I think, rather than rely on using a bit of (flammable) R32 to flush the pipes out. The bits should be here by the end of next week, with luck, and I'll update this thread with a progress report.

The Claber system I installed last year came with a 20m length of small bore black pipe, and connects directly to an outside tap. Adding a longer length of pipe is easy, as the pipe they use seems to be pretty standard stuff that's available fairly cheaply on eBay: https://www.ebay.co.uk/itm/Micro-Feeding-Tube-Pipe-4mm-id-6mm-od-Hozelock-Claber-Compatible-Micro-Watering/281730798058?hash=item419876d1ea:m:mL7Hgmt3f-wJpH3DlusxZig

Should work OK, just a matter of adjusting the dripper feeding the bird bath to supply just enough water. Easy to do, but would need a bit of trial and error to get the setting right. Best run with a timer, so that the bird bath only fills at set times during the day, so the time periods would need some fiddling with too.

AFAIK he's not got any thermal storage in the heating system other than the concrete in the passive slab. The Willis heater just sits in series with the UFH pipes as the heat source. Don't think he's got any PV yet, either. DHW is from a pair of electrically heated Sunamp PV units, run in parallel.

Even an ASHP may not recover it's additional capital cost from the energy saving cost reduction through life. We're lucky, in that I bought a relatively cheap ASHP and installed it myself. It saves us around £300 a year in electricity cost, and the installed cost came to a bit over £2,000, so it needs to last for about 7 years before it starts to save us any money. If it had been installed by an MCS installer it would have cost around £4,000 installed, so would take the best part of 14 years to break even, and I suspect it may well be due for replacement at around that time. There's a reasonable case for doing as @TerryE has, and just fit a cheap immersion heater in a Willis tube for heating a low energy house. Capital investment probably well under £100.

Precisely. They are a bit notorious for not being easy to seal, and for the seals degrading over time, as there is sod all to keep the seal tight to the sliding frame/sash, or to seal consistently in the longer term between the sashes.

Our windows and doors were made in Cork, by Munster Joinery. The windows are fine in the main, but the doors leave a bit to be desired. Definitely at the budget end for high performance glazing, and a PITA to deal with as a company, but massively cheaper than the likes of Internorm, and it seems that even Internorm have had some stick here over quality and installation issues.

Very true. Once you've got your heating bill down to the level ours is, then there's no way a thermal store is ever going to recover it's installation cost before it dies from old age.

I've just checked the LD50 for Jack Daniel's Assuming that it's the ethyl alcohol in Jack Daniel's that may kill you, then the LD50 is lower than I'd have thought, about 585ml. That's not much over half a litre bottle, so it's unsurprising that alcohol poisoning seems relatively commonplace in A&E. Mind you, people seem to vary a great deal when it comes to the effect of alcohol. I shared a house with four other students years ago, and one of them would be pretty pissed after half a pint of beer, and completely unable to stand after a pint. This was consistent, and yet it didn't stop him drinking, it just meant we always ended up carrying him home from the SU bar.

1.7°C heat loss per week from a 20,000 litre tank is 39.67 kWh/week heat loss, about half the heating requirement for our house in winter. The heat loss rate isn't linear, though, it's proportional to the differential temperature between the tank contents and outside, so the heat loss rate will start high (when the tank is hot) then reduce as the tank contents cool (see Newton's Law of Cooling: https://en.wikipedia.org/wiki/Newton's_law_of_cooling). For a 20,000 litre tank that starts off at 80°C (about as hot as you would want it to be really) and ends up at 30°C (about as cool as it can be and still be of use for heating) then the heat stored over that 50°C range would be 1,166.67 kWh. That's less than would be needed to heat our house through winter by about 37%, and our (electric) heating costs around £130 a year (at E7 rates). You can do a rough assessment of the heating energy you use from taking your heating bill and working back to get the amount of energy, making an allowance for hot water energy (for us, hot water uses more energy than heating over the course of a year.

It's a bit of a joke, @Russell griffiths, aimed at those who suffer from chemical phobia: https://en.wikipedia.org/wiki/Dihydrogen_monoxide_parody By the way, the main flavouring ingredient in Coke is phosphoric acid, the stuff used in various "rust converter" products (it changes red ferric oxide into black ferric phosphate).

A 10,000 litre water tank, with a max temp of 80°C and a min usable temp of 30°C would store about 583 kWh, a bit over 1/3rd of our requirement, without allowing for heat loss. Realistically, we would need a seasonal heat store that would hold around 1,800 to 2000 kWh, allowing for heat losses that couldn't be usefully utilised. That means a water store of around 30,000 to 33,000 litres, heated to about 80°C at the start of the heating season.

That is for about that period, as the house doesn't need heating outside the winter. We were running the cooling system by late April...

The total heating demand is around 1,600 kWh per year. That would need a Sunamp that's around 178 times larger than the one we have, plus a bit to allow for losses that may not contribute to heating the house. Part of the "secret source" in the Sunamp PCM seems to be the way that it's been tuned to start and stop the crystallisation process. As I understand it, the PCM does sit at around the 58°C phase transition temperature, though, so does lose heat at a fairly steady rate. The heat loss from our 9 kWh unit is around 700 Wh/24h IIRC. The insulation is vacuum panels, so a lot better than just any reasonable foam insulation.

Dangerous stuff, it has an LD50 (the dose that will kill 50% of those who take it) of about 6 litres. The really scary bit is that dihydrogen monoxide is supplied to households and comes out of taps...

That's true. We have a load of built-in stuff, apart from the kitchen units, and that added a bit to the cost. Putting stand-alone toilets and washbasins in would probably have been half the cost.