SteamyTea

I am going out as it is Comic Day, but shall look for it when I get free.

Yes. But welcome anyway. I got as far as the windows being fitted. So how did they seal between the window frames and the old opening, did they use any airtight tapes, or the usual can of foam? As you have a drawn plan, now is an ideal time to take a stab at a room by room heat loss calculation. It will take a bit of work finding out what each element is made from, but well worth it.

Not sure I understand the second part. This may be a topic for a new thread.

At work we are, not sure what the actual legislation is in the domestic setting.

Why so Very specific conditions have to be met to actually get infected Those conditions just don't happen in the domestic UK DHW systems. Most houses have chlorinated water supply, don't store much water for very long, and then don't atomise that water to the perfect size to be inhaled by a high risk person. Unlike old A/C units that used recycled water to cool. Just the presents of the bacteria in the water supply us not enough to cause a problem.

Or worse, powering your neighbours house as they run the tumble dryer on a sunny day.

Generally it buffers as a liquid, not a vapour, so the risk is the same. Having said that, I am of the mind that a few grams of liquid water does not pose a long term problem. If it did, all newly build masonry buildings would rot the timbers in no time.

Cheers, mother (expletive deleted)er

Yes, I have been saying that for years on here. The joints will need to be treated when it is dry, but as they can be done in a very short space of time, and the joint can be made near enough rain proof with a PU adhesive during installation, it is not much of a problem. One advantage of sheathing a substrate is that it is done in a workshop, where there is less problems with weather, the UV in sunlight can cause the exposed surface to cure faster than what is next to the substrate, this can cause problems with under curing. Another really big advantage is that it is easy to sheath different substrates i.e. thin ply, thicker OSB, foam sheets. If you want to get really posh, different surface finishes can be incorporated i.e. non slip, arty patterns, fake tiles. I really do think that GRP is an underused material, but I think most of that comes from the industry 'doing it on the cheap' and as an afterthought/panic measure, rather than incorporating it at the design stage.

I wonder where that money comes from. Oh yes, the rest of us poor (expletive deleted)ers.

I started using GRP 49 years ago. I suspect that the remains of that kayak is still not rotting away at the bottom of the Isis between Newbridge and Northmoor.

Mist is condensed water vapour, so needs to be treated differently. Needs to be treated as rain, not vapour. Below is the data near me for last year. At temperatures below 16°C the RH is pretty consistent at around 86%. That accounts for 79% of the time (don't tell emmets that it is really cold and damp in Cornwall). Say climate change raises the temperature by 1°C, from 12°C up to 13°C, the RH will reduce by 2%, to 84%, really nothing in reality.

No, on two fronts. kW, is power, Kw is nonsense. Now a W is a unit of energy per second, J/s or J.s-1. The SI unit for energy is the joule, not Joule, that was the man it is named after. it is a derived unit made up from SI base units of kg⋅m2⋅s−2 An hour is 3,600 seconds. So, even correcting the Kw to kW, we have, in your example: 3,000 [J.s-1] / 3600 [s] = 0.83 J, which works out as 2.3 x 10-7 kWh, so small to be meaningless. Now if your energy usage, over 24 hours, is 56.5 [kWh] then to convert it to power [kW], just divide by the time [24h]. 56.5 [kWh] / 24 [h] = 2.35 kW (the time, h, cancels out).

Quite often when companies sell you a product on staged payments, they are more interested in the commission they receive from the finance houses. This was very much the case with car sales 30 years ago, the finance commission was greater than the sales profit. The trouble with this is that it leads to mis selling, and that does absolutely no one any favours. The UK over the last 20 years or so has had similar initiatives, but they have all failed. Roof for Rent PV was a classic, as was the Green Investment Bank (2012 - 2017). I can remember many conversations over at the 'other place' about schemes that lend you money to invest in domestic RE and then you pay it back with a slightly higher energy unit cost. The idea being that overall, your annual bill is lower. Never happened. Then we had the FiTs and RHI. Now the FiT was a success, when it paid 3 times the unit price, now people complain that they only get a third of the unit price, so not worth installing PV. If you want a heat pump, go out and buy one, avoid all the government incentives and just do your own research on prices. While that may not help 'the little old pensioner neighbour', it may help you. If you don't have the knowledge to make a decision, read up on it more. None of us where born with an innate understanding of thermodynamics, or poetry, for that matter.

Let us call it, at best, a mean of 50W. 0.05 [kW] x 8760 [hours] = 440 kWh/year. That is a 13% increase on my usage (~3,300 kWh/year). Or, to look at it another way, 10 gallons of diesel, nearly 700 miles, or an extra trip to see my Mother. I just done a speed check and got this, does not seem so bad.

I think you have summed it up quite well. Dew Point (condensation temperature) can be estimated quite accurately with this formula. Tdew °C = T(internal °C) - ((100 - RH(internal %))/5) The temperature gradient can be considered linear, so the middle point will be half the temperature difference. Using the typical ΔT of 20°C and an overall roof thickness of 0.25m and an internal relative humidity level of 60%. T = 20 - ((100 - 60)/5) T = 20 - (40 / 5) T = 20 - 8 T = 12 As the roof is 0.25m thick, and the ΔT is 20, that is 80°C.m-1 (20°C / 0.25m) Dividing by the dew point temperature, 12°C 80 [°C.m-1] / 12 [°C dewpoint] = 6.7 m-1 1 / 6.7 [m-1] = 0.15 m So in that situation, there is a condensation risk at 150mm and extending outwards. You can see why the insulation is preferred on the outside of the rafters. Now the real answer is how often do you get those conditions. I had a quick look at 2023 weather data for my location and the percentage of time when there was a greater than 20°C temperature difference was 0.36%. From my understanding, a warm roof is treated just like an ordinary wall (and why wouldn't it) in that you still need to fit a vapour control layer, this reduces the higher (generally) temperature and RH air migrating into the structure. (it is very early in the morning and I may have made a mistake, but shall let other find it)

Joe Grundy in the Archers always claimed that it was his Farmer's Lung that stopped him doing any hard work. Sing Along time https://en.wikipedia.org/wiki/File:Barwick_Green.ogg

Plan is important as well, you could have 1 metre wide and 150 metres long. https://www.dummies.com/article/academics-the-arts/math/calculus/how-to-use-differentiation-to-calculate-the-maximum-volume-of-a-box-192226/

Maybe because we have very poor quality control in the building industry. It is also populated with arseholes.

About 65 kWh I think.

The h cancel out, so becomes kW. Not Kw.

@Nic Are the grid squares 0.5m?

So a foot then

Yes, to a certain extent. In a small place like mine, it would make no difference, but if the place is a more complicated than a simple rectangle, there may possibly be savings to be made. It is why we do room by room heat loss calculations, they show up this sort of thing and help make the decisions.

Shame you sold your tape measure.