SteamyTea

What a brilliant tool.

Except we have been told to get rid of the old refrigerants. It is legislation not company policy.

Forgot this bit. The gasses currently used are being phased out and are almost certainly going to be replaced with CO2. CO2 is a much better gas as you can get delivery temperatures up to 90°C. Though how this affects the physical size of the units and the frosting issue I don't know yet.

I answered it, buy the correct cleaner

That does complicate it a bit. With an ASHP you have 3 temperatures to consider. The temperature you want your house at, which is affected by such things as insulation levels, airtightness, solar gain, wind losses etc. External air temperature, this affects the overall performance of the ASHP and gets more complicated when the affects of humidity are taken into account. The delivery temperature, this is just what temperature you want the heat pump side of the ASHP to output. Too high and the advantage of any heat pump is quickly lost. This is related to to the type of refrigerant gas used (more later). See above, you need to know the coefficient of performance at different temperature and RH levels for each output temperature. It is why an ASHP needs to be oversized. This is not a fault, it is just the way physics works. You can think of it as similar to the way that fossil fuels are made. Each year that organic matter grows to get laid down in the correct place on the earth for form fossil fuels, there is a variance caused by different weather. Some years more gets laid than others (bit like my love life). The end product, say natural gas, is just the store, same as a thermal store, in a way. I have no idea what my house is TBH. I've never been asked for it. Find out, or work it out, otherwise you are just guessing and can never make an informed decision. I suggested that the forum could have a calculator, but apparently it is 'too hard' to do. So we shall just keep answering the same question with the same incomplete answer. Or get a copy of @JSHarris's spreadsheet. Detailed weather data is available here: http://data.ceda.ac.uk/badc/ukcp09/data/gridded-land-obs/gridded-land-obs-daily/timeseries/maximum-temperature/ http://data.ceda.ac.uk/badc/ukcp09/data/gridded-land-obs/gridded-land-obs-daily/timeseries/minimum-temperature/ So no excuses for not knowing what the temperatures are.

Remember that when speccing an ASHP, you need to oversize them.

I tend to avoid the 'sticky stuff' these days, though I am always looking at houses and wonder why composites are not used more. Seems silly to me that we can make complicated shapes that are waterproof from cheap hand laminated GRP i.e. a fishpond, but we make walls and roofs of houses from small components with joints between them. And they tend to be put together by people with hangovers and little education in material science.

Dichloromethane is better for Polyurethanes, it will dissolved them when they have cured. Not flammable either. Why we used it when I was moulding PUs.

If it is acetone, you have the wrong stuff.

That was a design that had a cold tank above the hot cylinder, and some pipes running up the side wasn't it. My cylinder is a bog standard E7 one of 220 lt. Cold in the bottom, hot out the top, top pipe bends 90° then a T. One side goes to the FE tank in loft and other side supplies hot water. Initially I had losses similar you @JSHarris, but by lining the cupboard with 100mm celotex and lagging the pipework I now have that down to very little. Less than 0.5 kWh/day and probably less. So don't dismiss an ordinary system on a standard heat loss assumption, it can be easily overcome.

As usual, when talking about heating systems, there is a lot of bollocks spoken about the details. There are two basic ways to heat DHW. Directly when needed or heated and stored until needed. Directly heated when needed requires a large boiler, the more hot water needed, the larger the boiler. Stored until needed can use a much smaller output boiler, but it needs to run for longer to recharge the DHW cylinder. All the rest, that nonsense about vented or unvented, large cylinders or thermal stores, thermostatic valves, heat exchangers etc is just the detail bollocks. Similar with space heating in a way. You can heat the air directly or heat some water, then pump it around the place to radiators A radiator is really a convection heater, but an UFH systems is really just a large radiator. The theory is the same e.g. how much power will it deliver. All the rest is detail i.e. gas, oil, solid fuel, heat pumps, solar, PV. What it really comes down to is how easy it is to install and how well you can insulate the parts that need insulating and place the parts that are hot. One of the problems is that we have got used to combing and system gas boilers and most plumbers are only happy to use these. They are not really that efficient, just that natural gas is so cheap that it looks that way. But I think it is about time one of the plumbers did a few sketches of different wet heating systems and explained the differences between them. Trouble is that prejudiced comes into it and to the unwary that can cause problems and confusion. My view is keep it simple and split the space and DHW systems if possible. One size does not fit all.

Is the whole area you live in without gas? That makes a difference to peoples attitudes as they may well be used to all electric.

Part G of the building regs has it all. Page 36, 125 lt/person.day. Baths can never be big enough.

Patriotism is the last refuge of a scoundrel

The connectors are sometimes really hard to get apart, this is why they can become broken. Too many people pull them bu the cables rather than release them properly. Also to repair one you would need a proper crimper and crimps to do a proper job. And remember that each panel can produce about 70V and 3 or 4 amps, so 5 modules in series could be 350V. Get a good wallop of that.

RHI was really intended as a replacement for solid fuel/LPG/Oil in older properties. Wasn't really for new builds, they should be on gas if possible. None of government backed schemes are really intended for a new self build. Too many variables.

Yes, like Lancias, they had had their full lifespan before the monthly payments had finished.

Except the government told them to simplify the tariff structure. I am not sure how it is all going to work. When I work out my price per kWh, I look at the total price, so include VAT and meter rental. Since I have fixed my immersion heater and 'gone back to normal', my all in price works out at 17p/kWh, which is not too bad really. Sometimes, like two days ago, I only used 4 kWh, and only 59% of that at night. That makes it an all in price of 22p/kWh. Roll on winter and I will, on paper, get really low kWh price.

Seriously, do you need all season tyres and 4 wheel drive in Nottinghamshire. I used to travel the length and breadths of the country in a Peugeot 309, sometimes I would tow a 21 foot spar-bath, on a much longer trailer. I really don't get this 'every eventuality must be covered' thing at all.

Don't think Poundland have gone bust, that was Poundworld.

£1 from Poundland

I thought my E7 meter rental at 23p/day was high, In the last 2 months I have only spent more than that per day on 16 occasions, and that includes taxes.

You are playing with unearthed DC, so you become part of the earth circuit. Now this should not be a problem as each junction should be designed to be save to handle. But if one is broken and a wire exposed, even in fairly low light you can get a nasty shock, and you will be on a roof. So take great care in what you are doing.

I seem to remember that you need to turn the invert off before you turn the DC side off, though should not matter if you are playing at night. It is not unusual to loose a string and in ever case I looked at it was always a connector that had loosened. Sometimes these are really hard to snap together, and even harder to unsnap. Pain in the arse if it is one under a module, they are usually hard to get to even with scaffolding. If it s a major job, then MCS are meant to step in and fix it if the company has stopped trading. But good luck with claiming via them.

Welcome Bit of Es and Whizz and it will be done in no time. Have you thought of just renovating to a high standard? Seems a nice place to me, but then I live in a 1987 terrace. I know a guy who is currently building and ICF place, seems to be taking him forever (and he don't do much else). I teased him before he started about it and asked how he would get around the well know problems. 9 months on he is very sheepish about it all. Must go and have a look at it sometime soon.