SteamyTea

That is not where the embodied CO2 savings are to be made, there is just not enough of it in a building. The delivery to site will probably produce more CO2. There are a number of ways to reduce CO2, daily energy usage is probably the most important.

Find a new installer. You could consider an in roof fitting systems, they tend to look a lot better anyway.

If they are there to 'help' stabilise the wall in very windy weather, then they are most likely dealing with higher air pressure outside than inside, so compression, mainly. They are probably there for failure mode, than any real contribution to overall structural integrity. And into CWI maybe. Though if your wall is leaking enough water to drip if the bend on a wall tie, then the wall needs sorting, this is not the 1960 after all.

Structurally, they will not be as strong in compression. In reality, as wall ties will buckle quite easily when compressed, it won't make any difference I suspect. Probably near enough that same in tension. Maybe @Gus Potter can answer more in detail (I find his long responses brilliant).

You have to ask. Should be able to catch a newt or three.

Do you mean in series. Cold feed -- HP -- Heat Exchanger -- Willis -- Shower.

It is entropy. If you think of the current, best model, of the universe, it starts with a point that is at high temperature. As the universe expands, that energy gets dispersed over time. That is work being done, energy (heat) is moved over time. To get back to the original state (the big crunch) would need all the universe to be collected and compressed to one point. PV/T (pressure x volume / temperature) The kicker is that to do that, energy would have to be used (moving a mass a distance takes energy). That energy needs to come from somewhere. What happens is a closed system is that part of the original energy is used to collect all the particles and move them to one point. This causes some parts of the system to have a lower mean temperature, and one part to have a higher mean temperature, as this goes on, the cold parts will react absolute zero (0K) and no movement will happen (zero kinetic energy). Because there is a temperature difference, some of the energy (heat) from the hot part will move to the cold part, which then starts to move again. As temperature is the mean, free path, molecular speed (a thermometer is a speed camera from molecules), those slightly warmed particles will move again. But as it is based on a mean temperature, some will be very hot, some very cold, it is that ratio of hot to cold that does the work (power), but it takes time. So you can think of it as a box of 1000 1 kg rocks that needs to be moved 1 metre. You can do it all in one go, or move the rocks individually. The energy needed is the same 1 kJ, but energy is needed to move them, 1 kJ. Now as you know, moving a tonne of rocks is hard work and will make you sweat, so that is where the extra energy comes from. There are some peculiarities in the mathematics that involve forces, and as you remember, F = MA, force (newton) is mass (kg) x acceleration (m.s-2). So the only way to get all the power back and convert it to energy, is to do it in zero time. And that cannot happen (excluding some ideas from the quantum realm). So it is not a case of technology, just a case of it is hard to get the hot particles and move them to the hotter part. Maxwell created his daemons as a thought experiment, but that is all it is, not a real machine.

So not the same thing.

That is like saying that distance and speed are the same thing.

So work is not the rate at which heat is used then?

A relatively small PV array will offset ToU costs. I am starting to think that any thermal storage needs to in conjunction with PV if possible.

It is still 2005 down here. Always make me giggle when emmets are here in the latest fashion, or worse, what they think the locals wear. Cornish national dress is shorts, T-shirt and flipflops.

The theoretical, maximum, efficient from a heat engine. Heat is the old word for energy, so can be used in some non thermal applications. More applicable to thermal applications though. I was also thinking about why ICE engines are so rubbish while wondering about all this thermodynamics.

Had a while to kill, so had a think about efficiency of heat pumps. Basically there are 3 variables, Power, Temperature in the cold side and Temperature on the hot side. These should fit a curve that follows 1-√(Tc/Th) for efficiency at maximum power. I have used a simple scale, 0 is nothing, 1 is everything. Because this is a heat pump, the y-axis can be scaled to represent CoP. To establish the true efficiency of a heat pump, data really needs to be collected for OAT, IAT and flow rates (both air/water and delivery depending on setup).

I think it can only be compared to the idealised Carnot cycle because, as you say, different systems use different control.