JohnMo

That's a lot of solar, or passivhaus and still quite a lot of solar. Good advertising but not many will be able to meet the requirements - big roof also needed.

Just seen a mistake and can no longer edit. The above should read 5.8 degs.

Made some adjustments based on information provided here and on Renewable Heating Hub. Prior to stating Below Target start delta was 8 degs Above Target stop delta was 0.4. Target flow temp 30.2. with a small WC curve rise to 35 flow at -3. This morning it was close to 11 degs, which is above where I would normally heat. After some tuning got to 2 starts per hour and a 15 to 20 min run time. The sun came out at lunch and the heat pump hasn't restarted, living room at 21.6. ASHP return temp is sitting at 21.1. So setting are quite different Below Target start delta is now 5.8 degs Above Target stop delta is now 2.0 degs. Target flow temp 25 at 14, with a WC curve to -5 and max flow temp of 32.6 degs. Upside is it should run without any house thermostats and generally look after it's self. Just need some warm weather to set up cooling. So the take away are 1. An aspect never discussed is how the heat pump responds to target flow temp. 2. What manufacturer default to may be miles away from what is needed. 3. You don't have to suffer short cycling, it fixable with a little time. 4. Base running target temp has been reduced a whole 5 degs - which should see an uplift of 0.5 in CoP.

Go for something like a Shelly, buy directly off their website, save getting dodgy knock off.

If it's all true, and matches the blurb maybe a good option. We generated next to nothing the last few days, really cloudy so everything was imported, really should have a surplus this time of year. But you can't do much with the weather, unless you have some sort of cost guarantee.

Not if it has aluminium foil either side, not sure how it could be. May be different if it's one of the grades, that has tissue or whatever on it.

That could be more to do with pressure drop than anything else. Normal diverter valves have quite large pressure drops, so when you start pumping more than about 1.5m3/h the drop is quite big, even with 28mm valves.

They are adding more and more wind in Scotland - why because the big plan is hydrogen - using excess wind power to make it.

Mine is a ground bearing slab, insulation and the concrete floor, instead of block and beam. My drainage is under the slab and brought through the insulation. Used insulation formers where drain runs under showers and bath would go to stop concrete getting there. Then once drains were sorted I back filled with concrete. Not sure if the exact logistics of drains and block and beam, but suspect similar.

The farmer says he gets it nothing, six lorry loads the other day. He possibly fits into the bracket Most will be burnt by this time next year.

Not when they are huge companies like in Scotland, they buy the whole forest years in advance, when they start cutting they don't stop until the whole area is cleared and then they replant the whole area.

No - good old pine

The farmer next to me has half a field full of wood (trees just felled) to make into fire wood. Gets it from the wood mills free or almost, as they don't want it at the moment.

My floor is 100mm fibre reinforced (think I did C30), paddle floated. Had a few low areas so just used self leveling screed where needed to get it level. Wet rooms are tiles, nearly everywhere else is wood glued down, bedrooms are carpet. My floor was done before any walls were built, easy access, no walls in the way.

Add more insulation if you can. Use the 75mm as your floor and clip the UFH pipes to the insulation, prior to pouring the concrete.

Started my new trial. Overshoot set for 3.0 and flow target set for 26, OAT is 12. Wouldn't normally have the heating on, so a good test for how cycling is affected. First run, ran for 1.25 hrs. Then sat idle for 1.5 hrs. On the next start I reduced the overshoot to 2.5 degs. But DHW heating kicked in. Currently on a thermostat override to keep on to see how it does. Will leave to run the rest of the day.

Had a trial last night have been playing with this myself. LWT from the heat pump is controlled a couple of parameters. To start the heat pump the LWT has to be set delta temperature below target flow temperature. To stop the heat cycle it has to be a set delta temperature above target. The factory settings on my heat pump for the compressor starting dT plus 2 degs and for stopping the compressor 0.2 above target. I did change these last year to 0.4 above. But always noticed a reasonably short cycle time so at 7 OAT would run for 15 minutes and off the 20. Which in it's self is ok, but not the most efficient. With a gas boiler I could run at 25 degrees flow temp, but to get the same heat into the house I now need to run at 29. So last night, set the target flow temperature to 26 and overshoot to 4 degs and the heat pump ran for 20+ before I shut it off. It would have run longer, was at 29.1 when I stopped it. So can get a decent cycle time easy enough, a low target flow temp will ensure the compressor doesn't restart too quickly. But can be manipulated with the circulation running in intermittent or sniffer mode My run, data from the battery so is whole house. It's in 5 min snap shots, but you can see the drop in load at about 5 mins after it's hit target temp. Flow target was 26 degs, end temp when I shut down was 29.1. We have a wet dull cool day again today, will will let the heat pump do a couple of cycles to see what it does.

You will either have a single 3 port diverter or 2x 2 port valves. Were any of these put in to a manual position and not reset?

Do you have an auto mode Unfortunately not. So may have to set something up manually. But luckily have lots of concrete to soak up the heat. Interesting to see the different schemes in place from various manufacturers.

Anything from a 1 min to about 10 min. Once you get to around 10 mins your heat pump has started modulation and you are getting a reasonable CoP. So the longer run you can get the better.

Scotland wanted devolved powers, and that is one of them. Not much you can do about until Scottish election time.

Many heat pump suffer short cycling or fairly short run times in shoulder months, mine included. So in an attempt to understand this more clearly and hopefully developing a coping strategy for all I am after some information. Water leaving temperature will have a target temp let's say 30 degrees, the heat pump has hysterisis for stopping and starting around this temp. So mine (Maxa) it is To start heating CH water the return water needed to be target delta T (between flow and return) + and adjustable 2 degs. So at 30 Deg the flow has to of reduced to between 22-23 Deg. To stop heating the overshoot is allowed to to 0.2 degs over so 30.2 degs. Grant/Chofu heat pumps are Start 8 degs below target (22 Deg) Stop 1 Deg above target (31 degs) The above are adjustable settings What is yours? Make Heating type - radiators, UFH or mixed. Another interesting feature is circulation pump option mode. Run always when there is a heating demand and sniffer mode, with only periodic running of circulation pump, one for a minute off for 10 mins. Do you know how yours operates?

The top image is a ubbink terminal, the sock just goes over the spring clips. These were my last buy https://www.paulheatrecovery.co.uk/product/filter-cone-125/

Your simple option is trickle vents, but only in dry rooms, but you don't want the standard open or shut ones, you need to upgrade to self modulating or humidity sensitive. Then you need dMEV fans in every wet room. Next level of complexity as you need to add ducts, is a central extract unit (MEV) with humidity control.

Nothing that wrong that except Bring DPM up the walls Add a perimeter insulation to top of screed. Replace EPS with PIR, 150mm EPS isn't good enough for UFH. PIR compared to EPS will result in 50% better U value. The floor as is, will be drafty so is part of the original ventilation strategy. So you need to think about house ventilation also.