SteamyTea

I would not say that. When you only need a small increase, or decrease, in temperature, you may find it works well. Really just a case of doing the numbers and seeing how much can be transferred on the highest flow settings.

I know what you are saying, but that is a problem with incorrectly designed and sized systems, it is not an intrinsic problem with ASHPs.

One of those "Yes and No". For sizing radiators/UFH, then the maximum load is what matters. To get an efficient system, then the most likely loads is needed. The truth is somewhere between the two (I may have to look at that as it is an interesting statistical problem).

Incidental heating may make a difference, you can work out solar gain easily enough using PVGIS. Just set the window area angle to vertical, then see what the table shows.

Increasing the diameter of the MVHR ducting can greatly increase the ACH figures. That may be enough to have some useful contribution from the AC or heating system. Pi x r2 It is the 2 bit that makes a huge difference.

You need to know the transfer between rooms as well, unless you are modelling the place with only 1 internal temperature.

Let's tackle the problem from another direction. What is the power range of your heat pump? i.e. 3 to 12 kW What is the heat load range? 4 to 7 kW Then it should be easy to work out if a buffer is needed.

Pronounced Colin, in French. Why it smells like it does.

The Fishermen do that, they spend too long at sea.

Yesterday, there was a trail of collies leading out of Penzance, we have loads, but as they are all Brexiteers down here, they are going to keep them for the fishermen.

I remember it all too well, mate of mine is a farmer. But the science (regarding human health) was patching and quickly discredited. Did not stop the Red Tops stirring up trouble, and it was a good reason to kick Edwina a bit more. Science is really discredited by schools, they need to make it relevant, or it is just another maths lesson. It is a shame, as it can be fun.

On a very small, selected sample. This test seems to work best on people that are relatively ill with it already i.e. high load. As much as I like the idea of a very quick test, it needs to be at least 99% accurate. To put that into perspective, MCS need, for RHI purposes, 99% of the heat load covered. Or Would you get in a taxi if there was a 1% chance that it would have an accident, with the outcome unknown. And this test, at its realistic best, is allowing over a quarter of the positive people getting a negative result. So like taking a taxi for the 4th time.

That will be the test that misses 58% of positive results. https://www.bmj.com/content/371/bmj.m4469

No. Damn, onto my next liberal tactic then, I am getting a new box of them for Christmas.

Does that mean I have won.

You really talk bollocks don't you.

No, a biased, fake correlation. We have moved on from the 1970s in both statistics and attitude. The very nature of immigration is that it works both ways. Why the French are introducing a 'protocol'. Ours will be better, World Class in fact.

Thought you would approve, keeping immigrants out.

Just a general observation. Putting in a buffer will reduce short cycling of the heat source. Taking a simple example of allowing a 100 lt buffer to vary between 30°C and 45°C, and not taking any external draw from it, the times will vary for different power sources. (this chart breaks convention by putting time on the y-axis, but is correct as time varies with power, with power being the controlled variable)

Yes, I assumed it was an electric one. Must have missed it was coming from a UVC. Or use Bernoulli's empirical formula: P1 + 1/2 ρv12 + ρ_gh_1 = P2 + 1/2 ρv22 + ρgh2 Where P = Pressure v = Volume ρ = Density g = Gravity h = height For a level pipe run, ρ_gh_1 cancels out with ρgh2

The flow rate will possibly change (or the temperature change) depending on the temperature difference between the cold, incoming mains, and the temperature you want the shower to deliver. Knowing the power (kW) will tell you what temperature lift you can get for any given flow rate. 4.18 [kJ.kg-1.K-1] x kg.s-1 [flow rate]. (T1 - T0) [temperature increase]

Picked the wrong area of science then. Thermodynamics is the Royalty of Science. Basically you have a cold side and a hot side, just like any heat engine. What goes on in the middle is irrelevant, but in the case of heat pumps it is the expansion (cooling) and compression (heating), that does the work. Where it differs from a combustion engine is that the cold side is below ambient temperature and the hot side is is above ambient temperature, though not as much as a combustion engine. Though the overall temperature differences may well be similar i.e. 70°C to 80°C. It just starts at a lower temperature say -30°C. So when you need to cool, it is really just a bit of plumbing change, pump the cold side around the house, cool the hot side with external ambient air. When heating DHW, it ramps up temperature (compresses harder) and diverts this to the cylinder (lots of debate about cylinders, they are only a bucket of water that starts at a low temperature and gets heated, ready for use), while disconnecting the rest of the system. The thing to remember with a heat pump is that as they approach their maximum output, the CoP (efficiency multiplier) drops towards parity i.e. 1 kWh in, 1 kWh out. This is why they need to be oversized, usually around 30% above the power (the kW, not the kWh) of the DHW requirement heating times i.e. a sensible reheat time, say 2 hours.

Apart from the 'electrical and structural' side, the MCS specifies approved modules. You can have any inverter you like, as long as it is acceptable to the DNOs. Battery systems are basically an add on, so as long as they are properly fitted and are safe, then they are not part of it. As a general note with MCS, there is a lot of paperwork that has nothing to do with the actual fitted systems, this includes quality assurance systems and staff monitoring, or as we used to call it, traceability, dispute resolution etc. This is where part of the MCS cost is, you are paying for things that may never be needed.

All bottom feeders, best avoided. I often watch the seagulls feeding at the end of the sewage pipes at Porthleven and St. Ives, and wonder why they prefer human scat over chips and ice cream. Then I chatted to @pocster.

As you are in all day, and assuming that you need power then, try comparing the very lowest tariff you can find with a standard E7 one. The day rate for E7 can be quite painful, but for a lot of the year you will be reducing that with the PV, and when the PV is at its worst, you may find that the heavy heating load can be satisfied with just night time usage. It is all a juggling game and without high quality data it is impossible to suggest anything more than generalisation.