SteamyTea

More so as it uses, in part, atmospheric moisture. There seems to be a myth that cement mixes are simple, mix up the components, pour and tamp into the right place, then speed up the drying. The chemistry is much more complicated.

Sit it out. It does not dry via evaporation, it cures via a multistage chemical reaction. Part of that reaction generates heat that starts another part of the reaction. If you skip one stage, the mix does not react correctly.

No hope needed. Download a copy of ICE from here. https://circularecology.com/embodied-carbon-footprint-database.html It can quickly show which are the better materials environmentally.

You have to define what you mean by 'eco friendly'. When I was at university doing my environmental science degree, most of the course was made up of ecologists, then there were 4 surf science students, one marine management student and 3 of us from the renewable energy course. The surfers have had the biggest impact in cleaning up the environment.

Brilliant, especially if they are 10 metres or more high.

Much of that will depend on how it is wired up. A lot of inverters can take 1000V input which reduces the current, and therefore the cable size. Does it really have to be 150m away?

The base crude oil it came from quite possibly was more local to where the foam was made, Gulf of Mexico, Texas, Canada, the USA is still the largest producer of crude oil, so makes sense to make products there. If the foam was made in the Western USA, it could have been processed with lower carbon fuel sources, wind, solar and hydro. Transport by rail and ships is the best way to reduce transport embodied energy and carbon in high volume products. Not as if they pop the stuff in a plane. The UK has very high transport energy costs as we move just about everything by relatively small trucks. Ask @ToughButterCup about not bracing Durisol, and if you are really concerned about environmental damage, why are you not building a timber house? You can look up the embodied energy and carbon for building materials on the University of Bath's website, Craig Jones is the man. You need, if you want to be environmentally sound, pick products from the most productive factories, not the ones near by. Productive factories are more efficient. In Economics, it is called division of labour. Let people that are good at something get on with it, those that are not good at something need to do something else.

I always used to think that, but now I am not so sure. But as it will hardly raise the temperature at all, and air leakage will just about make it unmeasurable, it is hardly a gain. Then comes the second part, the CoP of the heat pump (different for direct heating). Take today, my OAT is about 10°C and my IAT about 21°C, a reasonably set up ASHP will probably be getting a CoP of around 4.5. But to heat water, the CoP may be about 3, and if that water was heating early morning, maybe only 2.5. So in reality, loosing that 1 kWh from the cylinder costs more.

About the same. I have a very bog standard 200lt E7 VC and that does not lose much more.

Temperature stability maybe because of the phase change temperature, but that can be affected by flow rate.

https://www.theguardian.com/technology/2024/mar/14/much-of-west-and-central-africa-without-internet-after-undersea-cable-failures Have you ever been to Porth Curnow? Zooming in on those sheds. That is where a lot of our 'internet' comes in.

They did seem to give a lot of bother. Don't scare yourself, it may work out at 50p/kWh. No, that is not the way to work it out. You have to take your mean price. So as I use about 11 kWh/day, and 10 of those are at 15p and the other one at 35p, that is 17p/kWh.

See above

I use about 300 kWh/month in the winter to keep my house warm. So approximately 10 kWh/day. Initially I shall assume that there is no added input in December and January, so I need to store 600 kWh. Water would be the most cost effective medium to store energy in as it is cheap and easily transportable. Water stores about 0.00116 kWh.kg-1.K-1. So I would need, if I could get a ΔT of 40K (40°C up to 80°C as anything below 40°C would not really be useful) to store approximately 6,500 litres. If they were stored in rectangular vessels, I would need 7 m3, so quite a big hole. That is before adding insulation. Realistically PIR with a k-value 0.025 W.m-1K-1 is the most practical. So how much would I need. Assuming that my ground is at 10°C once deeper than 1 meter, the vessel is 7 metres long, by 1 metre wide and 1 metre tall, I would have a surface area of 30m2 to insulate. If I added 1 metre of insulation onto each side, then that is 9m by 3m by 3m hole I would need to dig, 81m3, the surface area would be 126m2, that is about half the volume of my house and nearly the same surface area (house is 184m2). So what would the heat losses be. R-Value = 1 [m] / 0.025 [k-value] = 40 U-Value = 1 / 40 [R-Value] = 0.025 W.m-2.K-1 Power [W] = 0.025 [W.m-2.K-1] x 126 [m2] x 70 [ΔT] = 220 W or 5.3 kWh/day. Knocking up a quick mathematical model, the losses, before any usage, look like this: So that is 254 kWh of useful energy lost. So what to do. Two options really (well 3). Add more insulation, which is expensive. Doubling the thickness will give a surface area of 270 m2 and a volume of 275m3. That is now much larger than my house, but no matter, lets work out the losses as I am full of hope. 2 metre thickness of insulation works out as a U-Value of 0.0125 W.m-2.K-1. Now this throws up a strange result, the losses are actually greater, 272 kWh total, because the total surface area has increased by 144 m2. Now there is some dispute as to where the thermal losses should me measured. I always use the outside area as this is larger. Just for a laugh, and I had a good snooze this afternoon, let us see what the losses are when using the surface area of just the water container, the 7m x 1m x 1m, 30m2. At a U-Value of 0.025, it is 60 kWh total, and at 0.0125 30 kWh. Now the truth is it will be somewhere between the two and without a much more detailed model, which allows for the corner affects i.e. effectively thicker insulation. So shall we settle on 155 kWh total losses. The second way is to increase the volume of storage by an extra cubic meter, that would store an extra 45 kWh but loose some of that to losses, about 7 kWh total. So we would actually have to add another 4m3, so a total storage of 11m3 of water. Now we could change the geometry to get the smallest surface area to insulate. This may need a custom container that is cube 2.25m on each side. Adding a metre thickness of insulation would expand that to 4.25m on each side, so a volume of 77m3 and an area of 108m2. The losses would now be 208 kWh total out of the original capacity of 510 kWh. Still not enough. Let us for a cube 3m on each side, that is easy as you can buy 1m by 1m by 1m vessels easy enough, and stack them in a cube. So that would have a storage capacity of 1254 kWh initially (at Δ40) and losses with 1m of insulation of 301 kWh, leaving a possible useful amount of 950 kWh. Big hole in the ground though, 5m on each side, 125m3 which is only 35m3 less than my house volume. Now I have only worked this out for a laugh, but I did it a few years back when @DamonHD and myself discussed it before, I think I came to the same conclusion, which is my third option, don't (expletive deleted)ing bother.

London has around 1410 hours of sunshine a year, Zurich 1566. Sunshine hours are a measure of clear sky, not intensity. Quite a different weather regime, and is 4° further south than London, so better intensity. London is the 4th cloudiest city in Europe. Glasgow is the cloudiest, then Birmingham, then Reykjavík. https://www.currentresults.com/Weather/index.php If interseasonal thermal stores worked, all our houses would have them, not as if it is a new concept and never been looked at before, or the world was waiting for some new materials like Hopium and Unobtainium. As a general point, it is worth reading up about Entropy, which explains, in a round about way, why it is so hard to get from a high entropy to a low entropy without putting in lower entropy. Entropy will be the death of us all, but it will not stop dreamers thinking they can beat nature.

That should be πr. Mate came around to show me his cataract operation arrow on his head.

Isn't area the square. Area =πr². The circumference is proportional to π

Oh dear, another set of dreamers that do not know the difference between power and energy. From the Sunsync site. Ridge Blade Keith Gough, Managing Director of #Sunsynk Ltd is visiting a wind turbine site in North Yorkshire. The turbine is called the Ridge Blade ® and its unique design allows it to generate power during levels of wind speed from low to high. This is a remarkable new design of turbine and destined to revolutionise the production of renewable power. At the present moment in low wind conditions the device is producing 240Wh, however if elevated it is forecast to produce 2kWh. Sunsynk will be monitoring developments with great interest!

Has any SA lasted a decade yet?

You need to calculate the thermal losses, then find out the most effective method. Getting the floor right is probably the most important thermal engineering thing you have to do, not as if you can change it once a few tonnes of building are on it.

It is more usual to use an auger for the loose stuff. Purely out if academic interest, what sort of tests are you going to do on the samples?

The smell of victory.

What poisons are for, has the advantage that it discourages friends with dogs visiting.

Right. Not very good for UFH. Take the example where the ground temperature is 10°C (quite high) and a mean flow temperature of 35°C. 0.18 [W.m-2.K-1] x 1 [m2] x 25 [ΔT] = 4.5 W.m-2 of energy needed before you start heating the air in the room. So if your room needs 10W.m-2 you actually need to supply 14.5W.m-2. If you get the U-Value down to 0.1 W.m-2.K-1, you will only need to supply 12.5W.m-2, a 15% saving.

Get that sorted, never a good thing.