SteamyTea

Exhaust air heat pump. It is like a normal air to air heat pump, but extracts the air out of the building to heat water. The problem is, the air in the building has to be heated, so can become very expensive if the heating is electrical resistance. Some on here have used them to good effect though, especially if it is integrated with the ventilation system and DHW usage is relatively low, in proportion to the building volume. DHW usage is really a function of occupancy, more people, more hot water used.

Discounting devalues. We don't drop our prices, even at the height of 'influencers' after a free meal. I vote with my feet, if something is not worth the money, I go elsewhere.

That is about 11 kWh. Say timber has an energy content of 4.5 kWh/kg. 2 kg is 9 kWh. I suspect your cylinder was not at 22°C.

Interesting as my mother's meter, with EDF, is blank. It has not been changed, but they know it is faulty. I am leaving it a bit longer so that from my complaint, and arrangement to change it, is over a year old. Thames water do not know where the water meter is as well. Arranged to get that sorted but no one turns up. House is empty now so bills are minimal.

Ah, the unknown that makes Britain the most productive country in the world.

You got further than I did.

Aerogel from wood. https://www.nature.com/articles/s41560-023-01226-7

Tell him if he works hard he can retire at age 64.

Every few years it is a Sunday. It is a Saturday this year.

"Is it April the first"

I think this is part of the misunderstanding. There is ability, intelligence, knowledge and qualifications. There is usually a decent balance, but we remember the ones that are unbalanced.

Will cost you £350/hour for me to read that.

Not in a lot if countries where the profession is protected. I started my engineering career as an apprentice, got my technicians certificate as it was called then (production engineering), then studied proper engineering (HND in Automotive Engineering), then a couple of years evening classes to upgrade it to a proper Degree. Then, many years later did two more Degrees (Renewable Energy and Environmental Science). I don't call myself an Environmental Engineer as that gets confused with the person that cleans the bogs in a cafe. A bog cleaner has probably contributed more to general healthiness than I have. I don't know why you would not get a thermodynamisist to design your heating, or a physicist to design the structure of a home. Are you getting engineering design and layout confused?

In the UK we tend to have quite low barriers to entry to set up a business. Apart from a few technical jobs, there are no barriers i.e. anyone can be a computer engineer, or gardener. We do tend to have high business running costs i.e. vehicles, premises, insurances. I cannot comment if customers have high expectations, I suspect they tend to be the same globally. What we do have a lot of in our trades, is qualification inflation. This is where the seemingly high prices charged come from. I pass a lot of vans with 'engineer' written on them. If you want pipes fitted, get a technician, if you want the heating system designed, get a thermodynamisists to design it. Not the other way around. That will lead to problems.

Depending on your roof angles, March can be a good month because the 'direct solar beam' aligns nicely with the roof, creating a flat plain. Yesterday Cornwall was getting, during the day, about a quarter of its electrical power from local solar.

There are often copies of the OnSite guided. They give you the derating factor.

Is that when in use, or constantly? My bathroom is similar in temperature to the rest of the upstairs, mainly because I never shut the door.

She does not end her shower in 6°C water. Humour me, next time she finished showering, run the hot kitchen tap and see what the temperature is.

@SimonD I may have missed it, but do you know your pressure test/ACH figures?

While that looks right, I doubt the whole 300 kg starts at 6°C. DHW below 30°C is of little use, that is a pretty cold shower. So less mass DHW is probably heated i.e. @ProDave washes less than he thinks. That like does not make sense. 52,718.4 kJ/3600 s = 14.644 kWh

If you just heat the air in the building you will have less overall thermal losses, which points to an A2A as opposed to A2W with UFH. Not sure what you mean there, water has an excellent specific heat capacity.

Ok. Cornish granite.

I think in reality they are all much of a muchness. The technology should not be confused with the sales department. Problem best to get one with the easiest to use controller.

Not as much as my imagination.