JohnMo

Depending really on if you want to grant harvest or not. I haven't bothered. One plumber should be able to do ASHP x2 and UFH and radiator upgrades. Just be sure you aren't being sold a pup, when only need a 6kW or less heat pump and they want to sell you a 12kW one. PV and battery should become contractor. ASHP and plumbing another.

They are not even that size. Well confused me when I first started buying timber.

Yep But not BTU's or inches for that matter.

Our foundations were complete in the November, walls up by Christmas, was f...ing freezing. Many a morning we would have to bail out the water accumulation before we started work proper. But ICF walls allowed concrete pours even in sub zero temps. Roof on in January. Then it was 99% dry even without the windows, just still cold. Our main issue was the floor was insulated before the walls went up, had 100mm concrete above the insulation, so if there was a sub zero night ,the house floor remained frozen all day

Isn't an insulated concrete slab better, for anything. At least you have only ground temp (6 degs) below you rather than a ventilation void that can be a cold as the air around the house.

I must be doing something wrong, I have to wait until temps drop to about -5 before I feel warm floors. Until then they aren't cold but certainly aren't warm.

I would all to can in PIR and where needed apply spray foam to fill gaps.

Steel, connected to ground will be a cold surface. Wrap in PIR and tape the joints, this gives vapour barrier. 25mm is normally enough but the more the merrier. Or insulation and wrap and tape a vapour barrier. Condensation will only form from constant contact with air

Don't have to have a charger on the wall, a 13A plug will do it. If you have a heat pump, would cosy maybe cheaper overall?

Sorry, you just clump it all in one sentence, can only respond to what I read. But as I said a well designed ASHP system is suitable for any property. But also not mentioned a piss poor design, can be be very bad in any property new or old.

Sorry this statement alone is just utter nonsense. A heat pump is suitable for any property, when correct designed. Why does it cost a fortune to install a heat pump in a new build? You already have to install low temp heating system to comply with BR. A 35 deg system isn't even going to much of a cost premium. If I can buy a new heat pump for £2100, a large organisation will buy for half that! Scotland banned gas boilers a while ago and whole building industry came to a standstill - not. ASHP, no gas standing charge, a single zone system, without hydraulic seperation, SCoP of 4 plus easily. Cheaper for the house holder, get over it.

My view, is do due diligence on anything you read. Who is writing it, what is their background - where is the money coming from, that allows the research and pays the bills. If you can't easily find these details ask yourself why not! Most likely it's going to filed in the nonsense pile or pile of, most likely sponsored, by some organisation with a view to spin.

We had a similar issue where contractors hit a mains water pipe, they got a fine and cost the repair. Bottom line they are the professional, they are the ones that made a mistake, or had an unavoidable incident, it's their issue to sort out, they are or should be insured for such events, if they aren't that isn't your concern or problem. Don't get involved, anyone comes and starts asking or telling you stuff is your issue, pass the contractors details to them. It's not your issue to question, it's the contractors - getting involved just gets you in the middle of stuff you need not be in the middle off. Tell the contractor to deal with it - it's the issue.

It takes all sorts - all opinions are good, even wrong ones. Deleted the rest of the comment, it's not worth the effort.

And if you have solar, no solar no export payments, unless things have changed in the last 3 months.

It does even with my 300mm pipe centres, its way more powerful when you get down to 100mm centres. Uber simple to get working, set flat WC curve, say at 19 degs, let that run 24/7, to keep floor slightly cooler than rooms, have cooling thermostat to switch to second set point say 16-17 degs flow temp, when room temps hits 23 deg. I will be using the smart grid terminals within the ASHP to demand a reaction of 2 Deg in flow temp. My UFH controller is switchable between cool and heat and so is the ASHP, so use a single repurposed light switch connected to both (used to provide a volt free open/closed signal), one position changes both to cool the other position to heat. Pretty much a no brainer, very cheap to run, when between 10 and 25 outside the CoP is between 7 and 9 in the tick away mode, you still get a CoP over 4 running flat out in boost mode when its 35 outside.

Don't assume the heat loss is correct check for yourself. I have been told by two companies I needed a 10kW ASHP, will be installing a 4kW on Saturday. Certainly don't install anything bigger than you need as part load performance (average winter day) will suffer. Do you have PV?

China? So we are ok, aren't we! Was in a Scottish ship yard, a year or two ago, full of wind turbines for offshore, all had been shipped from China

Been scratching my head how to set WC curves, one for heating the other for cooling, however I found because the unit was set to auto (auto switching between heat and cool) the menu wasn't visible. However switch to heat or cool and WC menu pop up. Very easy to set, so set a flat curve for cooling 16 deg (well above dew point) flow temp and heating the more normal curve. Will most likely need some adjustment once up and running.

https://coolenergyshop.com/collections/radiators-fan-coils?srsltid=AfmBOoo2Jwpa28-xTPSwQCmxyskK6onq3GBoEW004T_AV7JvfWtJQvZo Here are a couple of photos of ours which heats a summer house (a Myson unit). First is the unit without the cover installed, controller is on the right, a finned radiator panel behind the sheet metal and a linear fan below it. It basically modulates the fan speed to maintain a a set room temp. Way smaller than an equivalent radiator.

With it being upstairs and if doors are open you are likely to have warmer bedrooms, like it not, I would keep it simple. Just install panel heaters in bedrooms or the provision for them, keep the electric UFH in bathrooms. But if you are going for a grant (I just wouldn't bother) they will require all heating by ASHP. But to mess your head up more, are you likely to need cooling upstairs? If so just do fan coils for heating and cooling in bedrooms and bathrooms. Cool Energy do bathroom fan coil towel rails. Do mild cooling keep the water flow above dew point then no need for drains to be added.

Mostly a long run of piping, although getting what looks a good CoP, generally 3+ it wasn't really that good, as we got a big slug of cold water hit the cylinder coil and it cooled the vessel. So small recharge needed to add a disproportionate of energy. So will just leave heat pump to tick away, doing heating and cooling.

Plenty of companies do MEV. You want one that automatically adjusts fan speed for humidity levels with extract vents that open and close automatically also. Then couple that with humidity activated inlet vents either in window or through wall. Do some reading via Google Passivent, Deco, to name a couple. You need to have air movement with cross ventilation dry areas to wet and out the house. To allow this you also need door under cuts or through wall vent grills. I would keep it simple and do dMEV, with all the features mentioned above.

I've just simplified and started to do DHW direct via immersion only. Left all the piping valves etc in place so could revert later, if I wanted, but over the last 3 weeks haven't been shocked by electric usage.

So will be keeping the volumiser, it's in the return line, but after the diverter valve due to because retrofit. So it also had an ESBE diverter, which allowed the volumiser to be bypassed during the production. That bypass isn't needed, so actuator removed and all the insulation tidied up. Before After Not perfect but much better than it was. Still a filling/flushing valve to sort out, but in the difficult basket