ProDave

@JSHarris has produced a spreadsheet to model heat loss from a building and I can certainly say it gives accurate answers. you input your house details, wall and window U values and it tells you things like KW of heat loss at different temperatures. It accurately predicted the heat loss from my house when it is +20 inside and -10 outside is a shade over 2KW I am sure someone will be along with a link to download it.

Nor mine. That was a bit of a surprise when it came in last year (or was it the year before)

My advice if you are a novice and don't have professional tools, is to fit the units, get them fixed, nice and level and square, and then get a well trusted good joiner to come and cut and fit the worktops including the joint. You don't in years to come be looking at your less than perfect DIY corner joint. I know just the man up here but that is not much help to most. He did my Oak island worktop in a couple of hours:

A friend I used to work with tried to do a DIY Landrover gearbox out. Took the seats and floor out Tied a rope around the gearbox and round his shoulders, undid the bolts and started prising the gearbox off the engine. It was somewhat heavier than he expected and he followed it through the hole and ended up on the garage floor on top of the gearbox.

you mean after the BH curry night?

One of those trees would last me a season so that would be a lifetime supply for me. But we don't need the stove much and we don't heat hot water with it. But I would have no trouble finding people to give it too if I needed to get rid of it.

My point is, the sizes are not that "standard" Go to one of the sheds, and buy a length of "40mm waste pipe" and try fitting it into an OSMA solvent weld fitting. It will be too loose. The 50/110 fitting I bought on ebay indeed had a pipe hole exactly 50mm in diameter, no UK "50mm" pipe with it's OD of 56mm or whatever would fit in it. I learned LONG ago to buy all your waste pipe and fittings from the same place at the same time, then if something does not fit, you can take it back.

I have wondered if I can "calculate" the air tightness. I know the insulation values pretty well, and I know the predicted heat loss based on Jeremy's spreadsheet. If I tweak the air tightness levels in that so predicted energy loss exactly equals actual measured energy loss then I have arrived at my air tightness level?

No the current scams going round are "upgrades" I had 3 calls on Monday trying to persuade me to upgrade my system with some form of snake oil that will boost the output from the panels.

No, if you have a system under the FIT, leave well alone. This is the new scheme for post FIT systems, to stop the complaints that people are giving away electricity for free. You can claim the new export payment if you are under the FIT but you would then loose the 50% deemed export payment from the FIT payment and instead get paid for actual export. The payment rate is only about 5.5p so for me at that price, it is better going into the immersion heater.

You can get paid for export now, at about 5.5p per KWh exported. BUT you have to have a smart meter fitted, and your system must have been installed by an MCS installer to qualify. Given how little I export, the extra cost if I had paid for an MCS installer would never be repaid from the small export tariff.

Offer them a drive in my old Landrover. On second thoughts, no. I would prefer the gearbox and clutch continued to work.

Does it fit? That is the only important question.

Yes, like the people that tell you their septic tank has not been emptied for 20 years and it is still working perfectly.

Perhaps this demonstrates that an airtight house might be good for someone that understands it, but not so good for the average home owner who understands nothing?

^^ It will be interesting to see the shape of that graph post March 2019. It would not surprise me if it was flat.

All houses need ventilation as long as there are people in them. It is a shame they didn't fit mvhr as then she would not have to worry about the heat loss, but that is an unavoidable necessity. As others will testify, our new house with mvhr always feel very fresh inside.

Is is just central extraction or a full blown mvhr system? I am not surprised it gets stuffy with the ventilation turned off. I think it was Jeremy that plotted CO2 levels in his bedroom at the old house. Yes it was, here you go There is not much you can do apart to tell them the cause of the high CO2 is them breathing with the ventilation turned off. Tell them to turn the ventilation back on, or stop breathing......

I have looked at those and am very skeptical. My suspicion is they will use a lot of real time peak rate heat to power their convector heater element to achieve the comfort level they do. I would be interested to hear real world experience of how much off peak electricity they really use and how much peak rate?

Just be aware that UK plumbing fittings are described in strange ways. e.g I bought a 110mm to 50mm reducer from ebay. It was just that. Shame that UK "50mm" waste pipe is more like 63mm diameter.

The 2 issues are a thermal store needs to store water at a hotter temperature, so that alone means higher losses. Then just about every thermal store I have seen is a copper tank with spray foam insulation, which you can get in different thicknesses but they tend to have a weak link around the connections. Compare that to a Telford Stainless steel unvented cylinder which has the inner stainless steel tank, and an outer solid jacket with the gap full of insulation. This seems to give a better insulated cylinder with no weak point around the connections. Lag all the pipework in and out well and I get very little detectable heat loss and the room with the tank is not noticable warmer than other rooms. I wonder why nobody seems to make a thermal store of similar construction and lagging?

I think someone on here used that to get a heavy hearth into place.

There is a house near me, on a borehole with very hard water. About every 3 years I have to replace the failed immersion heater. and in the process I spoon out through the immersion heater hole about half a bucket load of scale.

Lightning is actually very uncommon here, it used to be a regular thing in Oxfordshire.

I thought about that. I would want to do a test to see how long the ice took to melt and lower the tray into place, Vs the curing time of the adhesive.