SteamyTea

It is arithmetic, not mathematics. Arithmetic is pretty boring really, and easy to make a mistake, but we have speadsheets. Always remember that temperature, power and energy are not the same thing. Ideally a system would respond to external stimuli, so if the house only needed 500W to keep it at the desired temperature, the HP would modulate down to this, but when it needs 4 kW, it would deliver it, all be at a lower overall efficiency. Trouble is, life is not like that and a HP needs to run between fixed parameters of temperature and power. This is why a buffer is fitted, it allows absorption of a higher power (either though higher temperature or larger delivery volume) before it is needed. A buffer needs to be insulated just like any storage system, and it does not need to have storage at maximum temperature all the time (can't change the volume so temperature is the only variable). Microbore is the Devil's Vas Difference or Urethra, it gets blocked, and we don't want that.

About a third of what we have lost. https://www.tuc.org.uk/research-analysis/reports/impact-covid-19-and-brexit-uk-economy

Second Law of Thermodynamics says the same thing.

No, they were saving them just for you.

https://youtu.be/BQJKQjXpGQA?t=81

First thing to decide is the thermal performance you want from this house. Then look at the best cost option to achieve it. All the rest is 'just' detail.

Good, you can be the forums expert by the morning.

Impress on him that you know what the technology is capable of, and the limitations, but you want it to work so that others can learn from it. A failed system tells people nothing in this circumstance, other than the designer is a twat. Have a hunt around the MCS site to find the design criteria that installers have to follow. Get your local weather data as well, Temperatures and RH, for as many years as possible, and at the best resolution you can get. Then you can do a risk analysis on the system frosting up.

What is the orientation and size? Try glucophate to kill the weeds. Good time to start spraying is now.

You also need to make sure there is plenty of room to fit one. If it is too cramped a space the plumber will do a crap job. With your quote, does it show insulation for relevant pipework?

With this sort of project, I usually defer to old GK Chesterton. "I’ve searched all the parks in all the cities and found no statues of committees"

Yes, I forgot that, only now on my second mug of tea. I hate the clocks changing. Because the TRVs have shut most of the radiators down. I just think that all domestic HP systems need buffer tanks. I suspect that traditional gas combis would work better with them as well.

Is that the worse case? Because makes it quite oversized. So should really be fitted to reduce the chance of short cycling, unless you have a large reserve of fluid in the radiators and pipework.

It could be a way of fiddling the charging point numbers. Governments like to do that.

That is about the same energy price when gasoline is a quid a litre. You obviously get better efficiency from an electric motor compared to an ICE.

The U-Value is of little consequence when looking at energy storage, it is, in effect, just the speed at which the losses happen (why it is measured in watts, not joules). Realistically, the U-Value will be similar i.e. your 1.5 W/m2.K, just that you have a larger amount to loose when you have a larger store. Better off spending your cash to get the U-Value down, you only spend that money once and it is a marginal increase in cost for the extra material, the fitting is about the same cost.

Those of you that are switching/have switched to a ToD tariff, can you keep a good record of your usage as well as the price (I assume the 'app' does that). Will be interesting to see what the overall savings are, once meter rental and VAT is added on. My power is coming it at 15p/kWh, but the last week, now that the heating is off, it is 18.6p/kWh, but my daily mean has gone from 23.8 kWh (87% night rate) down to 10.55 kWh (65% night rate), but that will almost halve in the net months. While it hurts to pay the high day rate to EDF, generally (this winter was a bit of an exception) my usage is very low.

Yes, or No, depends on the 'something else'. Energy cannot be created, it can only change its form. So, stored energy has to be created first, and this is where the confusion comes in. If, for instance, you need to raise the temperature of the building by 2° C, and you have 10 tonnes to heat, assuming brick/concrete, with a specific heat capacity of 0.8 kJ/kg.K, then you need 16,000 kJ (4.44 kWh), while at the same time as heating say 100 kg of air, that has a SHC of 1 kJ/kg.K, so an extra 200 kJ (0.056 kWh). But if you have a timber/insulation combination, you may be reducing the 10 tonnes to 2 tonnes, but the SHC may be higher, say 1.3 kJ/kg.K, then that initial heating load is reduced to 5,200 kJ (1.44 kWh), while the air heating load is the same. Now people argue that you get that difference (3 kWh) back when you turn the heating off, except some of it has leaked out to the atmosphere/ground. So by having a larger store of energy, you have a larger amount to loose, and as heat loss is non proportional, the larger the temperature differences, the larger the losses, and the faster those losses happen. Controlling losses, and gains, is the key to temperature stability, this is why people put blinds on oversized windows and have MVHR fitted. In the UK it is a rare day that the weather conditions are idea of stable passive heating, or cooling for that matter. Spend your time and money on insulation and airtightness, not on large windows, tonnes of concrete and aftermarket fixes.

First thing to do is an indepth heat analysis of your next build. Then you can start looking at what will service it. It is juts like buying a car. work out what it needs to do, then go looking at different models.

If he is a reasonable sized concern, and 50 employees says he is, then he will be doing a deal with the main importers and not fiddling about with local agents. He really needs to do his own research regarding the 'best' units as it is a combination of performance, reliability, easy of installation, commissioning, repairs. As a general rule, Japanese manufacturers are pretty good, but they do all work the same. Getting 50 plumbers to learn that it does now work or operate like a gas combi is going to be a struggle, he is probably best setting up his own training course. Has to be better than practicing on customers systems.

Time I am at work.

EDF have a habit of increasing prices, then dropping them again. Mine go up quite a bit next week, but I suspect by June they will be dropping again. EDF are in a bit of a corner as they cannot easily increase their nuclear capacity (and god knows they are trying to), and I am not sure they have spare cash to invest in OSW and PV.

They are probably trying to even out the usage so that you pay the same every month, regardless of usage. This is what monthly billing is all about, the energy companies cash flow, not accurate monthly billing for the user. This is why you get a discount compared to the standard variable rate. I have always stuck with variable rate and at the end of the year, it is within a tenner of the best deal I can get. Too many people have been suckered by the energy companies, and the mortgage companies with their long term fixed rates. Neither of them are doing the consumer a favour, and don't think they are.

Yes, date and meter readings. I assume you do not have an Economy 7 meter now, so just the unit number, but just in case you have not changed from E7, you will have 3 numbers to write down, usually denoted as T, 1 and . Write them all down, with the date.

is that because you are on estimated monthly billing? If so, they won't match your physical readings, why would they.