SteamyTea

Shaw Taylor used to say if you see a crime to go home and forget all about it.

stick that on all the walls, then the insulation. You get best of both worlds then. Nothing to stop you filling the cavity with beads to. How r you going to deal with cold bridges i.e. joists though the inner cavity?

Will that work as an airtight barrier?

Remember that you are using RH not AH Taking @andy's data, there will be 10g.m-3 of water in the air.

Does that mean you are going to have some extra long duct work?

I always fell dirty after reading hub sites.

No. It is to do with the mass of air that flows though the heat exhanger. A larger ASHP has a larger area heat exhanger. This allows a greater mass of air to pass though. As the energy is extracted by dropping the air temperature, less of a temperature drop is needed to extract the same amount of energy. This has the added bonus of less chance of freezing up, and less noise because of slower flows. I dislike using the fridge analogy, but if you leave your fridge door open a little bit, you may still have a lower temperature inside, but you will notice that the compressor is constantly running and there may be a lot of frosting up.

So does that mean that the membership vetting process is not working?

It was the admin being paranoid about 'spammers' I was told.

This running 24/7, setting back temperatures, or using at fixed times is all a bit confusing. My take on it is that even a system that is set for fixed temperature and run 24/7 does not actually do that. All it is doing is taking a que from the room thermostats and switching on if needed. Using a set back temperature basically just delays the switching on until the conditions are met i.e. between 8AM and 12 Noon, temperature less than 18°C. This is no different than using a thermostat with a large hysteresis. It is also what a buffer tank can do, but between the heat source and the room. There is possibly a reason to have the temperature variation within the buffer tank larger than the room thermostat hysteresis i.e. buffer temp range ± 5°C, room stat hysteresis ± 1°C. Run a lower temperature system at fixed times is alright, as long as it is powerful enough to reach the target temperature within a reasonable time i.e. 1 hour.

DHW and Space Heating are different things. They do things at different temperatures, at different times and for different reasons. Separate them. I am also concerned that people may spend a lot on capital equipment to take advantage of one energy suppliers latest tariff. Is there a guarantee that this tariff will remain in place for a decade?

The worse thing about blogs on here is that you cannot go back and edit things after half an hour, this is really a dumb idea.

Compared to newer lithium technology, yes. It is also very large. If you hope to get the full capacity out of chemical storage i.e. 1kWh storage and 1 kWh usage, then the efficiency is pretty appalling, all the components get hot, which s just throwing the energy away. This is why batteries are huge. They are , in effect, oversized. Which ever way you go being an off gridder, you will end up with a generator. Look into combined heat and power units. Then find a way to make them quieter.

Isn't that how it is done these days. A modern version of setting the alarm an hour early.

I am not sure about number 4. This is extra compulsory stuff for the sake of it. House fires happen so infrequently these days, and fatalities even less. And try getting one that works of mains pressure, the local waterboard will not guarantee that there will be enough flow when it is needed. There should be one set of rules, with one interpretation only, for the whole country. That would make life simple for everyone. 'Local Plans' are a nonsense. The only locals that contribute are the ones that have an interest.

Yes it is, goes to show that airtightness and good insulation is all that is needed. I think an MVHR extract up there is a good idea as that can scavenge a bit of warms when the sun is just right, but also control humidity, which is the important thing. Joe90 also has a good loft ladder, that helps.

As @PeterW pointed out, a buffer tank is not a thermal store, or even a UVC/VC. It is just there to smooth out the temperature fluctuations while also helping to keep the heat pump working within its optimum range. Think of it as a capacitor in an electrical circuit, rather than a battery. The formula for calculation is the same.

Start by going here: https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP Fill in all the details and then get the daily file. Averages on there own are of little use, you need to know your usage standard deviation. And having large batteries is only useful for a very short period of time, they need excess generation to charge up on the few sunny days to cover the one dull afternoon. Start looking at all the things that you can get rid of that use power.

Do you know how much insulation is under the pipes?

https://engineering.stackexchange.com/questions/8004/how-to-calculate-flow-rate-of-water-through-a-pipe

Or the easy way is to use Google and just search the site as the forum search is pretty poor.

Is that a WC related pun Did not take long to degenerate, well in my mind anyway.

It may reduce condensation.

Yes, nice boys.

Whose? Pocster or Colin's