SteamyTea

Or mass even. Weight should really be banned, mass and force should be the only terms used. Just think how much time I would save now if I had fallen asleep in my Physics lessons.

The company was small. The turbines were 4 or 5 kW. Not large, or worthwhile, but okay as turbines go, if on a hill or SW facing slope. But know what you mean. Electric generation requires large kit, even PV. Best left to the big boys to sort it out.

A kilogram is a standard unit of mass, mass is really the sum of all the 'stuff' in it. Weight is the combination of mass and a force applied to it. Usually Earth's gravity. The unit of Force is mass multiplied by acceleration, with the SI unit N, for newton. Worth remembering that acceleration is a change in speed, and/or direction. It is either positive or negative.

Some people never learnt. Good on you.

Yes, I had forgotten that. Apparently when they go wrong, you can get a very big bang.

Is that why they are fat?

How does it compare to normal rail mounted. It does seem a little steep, but falls into line at around £1000/kWp. When I worked for the small wind turbine manufacturer, the complete installation cost about £12,000, the turbine was a couple of £2. The financial backers wanted to halve the price, we pointed out that the savings were not to be made on the turbine, but on everything else.

Is the quite correct, there could be an error as they do happen.

Before going down this difficult route, can you actually afford to self build, it is generally more expensive that people ever imagine.

Should have had a GRP flat roof, I can stick just about anything to that.

From here. You can get two half trays at 28.60, so £57.20

All that really happen is that the outside unit, instead of of blowing air though a very cold radiator, it blows air though a warm radiator. To save that energy you would need to collect that warmed air as it exits the ASHP unit, then store it in something well insulated. Not really feasable. GSHP can be set up to warm the ground where the boreholes/slinkies are, but if you have moving ground water, the energy is just taken away. You may find that an EAHP works better, it takes that warm air out the house, with that air replaced with outside air. Would probably work well where I am because the OAT is never that high, 28°C is a very, very, rare event, over 22°C only happens for a few hours a year, like today, but now, at 21:50, it is 14°C, with the house at 21°C. It should be possible to design a system that can provide genuine air conditioning and recover that energy to heat DHW, while also providing UFH when it is needed. I think the real problem is cost and complexity, basically switching from heating a slab in winter to cooling air in summer, two different mediums need to to piped and controlled. Fain Coil Units in a forced air heating system may be one method that is a bit simpler, it works in offices. But no one wants to 'loose space'' to large duct work. But I would question how large that ductwork needs to be be a low energy dwelling, probably not as large as people imagine. I am all for just heating the air in a building if possible, then you can forget about wet pipework, water leaks, over complicated controls, reliance of 'heating engineers' that do not understand heat pumps and it would be easy to fit another FCU or three to a larger heat pump if more heating and cooling were needed, then can run in series, one after the other in an insulated box.

We will have to wait till the current working generation of Architects have all died. I was chatting to a lady in the cafe today, she runs a writing and publishing service. I somehow managed to mention that I have an interest in energy and usage. She said, 'me too, many of my clients write about energy' Me 'Oh yes, that is interesting' Her, ' yes, life energy' Me 'not really real energy is it, science has defined energy very accurately' Her 'yes, I know about quantum energy' Me, well I just looked at her bare legs and tried to take a peek down her blouse. FFS

Where you getting PV modules from for 50 quid? https://midsummerwholesale.co.uk/buy/roof-integrated-solar-pv

Or just totally replace it with something thermally better. I am sure @craig will know of a suitable product.

Well that made me angry, perpetuating the same myths, with very little knowledge, and polarised contributors. The BBC has some fantastic scientific programs, why can't they get a descent physicist to contribute.

BBC Radio 4's You and Yours is about to do a bit about energy saving in houses. https://www.bbc.co.uk/programmes/articles/1YnZrF9w7xR82St8d7Pgc6x/contact-you-yours#programmes-content They love horror stories.

The problem seems to the that the window frames will be sitting on the cold concrete surface. The inside part of the cill has a relatively small surface area, but the outside part is massive, and cold. That means the frame will also be cold. The frame will have a relatively large area when combined with the cold cill. I am not sure how low a window frame can get thermal transmittance, but will have to be good in both the vertical and horizontal planes.

Assuming 80⁰F Then the energy in that air is, if it started at 10⁰C is 41 kJ That is about a third of the energy that the cup of coffee I have just bought, 1,100 kJ. Even if it is 80⁰C, that is 500 kJ. Half the coffee. Now let us assume that the solar collector area is 2 m² and you are getting 1000 W/m² today. 2000W, or 2 kJ/s. To heat 41 kJ will take 20 seconds, 500 kJ, 250 s, or 4 minutes.

We have known that for generations.

They will still speak funny. https://en.wikipedia.org/wiki/Welsh_phonology

@@joe90 Won't be big enough to heat your place in Wales, Zoothorn will be sucking all the power to keep his place warm.

I was chatting to a heat pump guy a few years back and he said there had been a few commercial CO2 installations, mainly cooling. I also seem to remember there were a number of domestic CO2 units available about a decade ago. Maybe @markocosic knows more.

Not sure. One thing that is a problem is that the gas must not be corrosives, and play nicely with lubricants. Water and hydrogen can both be used, but they cause problems. From my limited understanding, hydrogen plays an important part in the phase change of the current generation of gassed, but it is bonded strongly to the carbon atoms.

Basically the refrigerant gasses, and much sturdier engineering. You can get CO2 heat pumps for domestic installation, they just tend to be expensive and there is a real lack of installers. Ammonia is flammable, and poisonous, but cheap to make. It is a good refrigerant and can also be used to power ICE, we make billions of litres of it every year.