JohnMo

Well done, once you get your head in the right pace fairly straight forward. Mine has nothing in the house, not even the controller. Bit of a faff being outside while commissioning, but after that there is no real reason to change stuff. The price of the odds and sods soon stack up. Not sure what you mean by this, as many systems can do all three. Mine does out the box. Think most ASHP are being controlled and function more like air-conditioning, as those manufacturers are the ones making most of them. Think some systems do offer this (many manufacturers seem to over think stuff), mine has a connection for DHW sensor or a volt free contact from a thermostat, three port valve wiring, and heating is just a volt free contact and a volt free contact to switch between heating and cooling

Yep

Connect a dry drain trap below to the 32mm, then do a 32 to 21.5 solvent adapter to the drain trap compression joint.

You can do overhangs quite cheaply if you make the the structural engineer think about, our total steels bill was £9k including full design, all surveys and the install.

I would take up their offer, which should be free, they will not want you coming back again, so should use a different, possibly a high adhesion primer. Looks like the primer has just sat on top of the factory coating, instead of bonding to it. Hence coming off easily. Any other option is going cost your back pocket, and may end up in the same place. Painted kitchen doors even when factory done, do chip and scratch, they will say it has patena.

Mains powered equipment is as cheap as chips, other voltages and DC equipment not cheap, even the light bulbs are expensive. Every electrician understands it, DC is a different animal that people are not used to. DC cabling tends to be quite big, so costs more to install. You can't go the Screwfix or similar place on a Sunday morning to pick something up. Complying with building regs is easy, not expensive and you know it's safe.

If I am correct in Germany, you have to be setup to run weather compensation. If zones aren't shutting down its likely to be wiring issue. Or at least that's the first thing to check. What's make, model of heat pump, and how is it controlled? You possibly need to split this into two sections, cylinder heating and house heating. Not having a mixer and pump isn't an issue, flow temperature is, so this will need to be decreased.

The Greenwood dMEV units are easy to adjust for flow rate and have a built-in humidity sensor. If you have a utility put in there and the kitchen. What will happen in practice is the bedroom trickle vents will open at night with breathing etc, any downstairs will close. But the dMEV fans keep running, those downstairs will drag the air from the bedrooms downstairs and out the house. The opposite will be true when everyone is downstairs.

You saved me some writing as that is exactly what I would recommend. Greenwood dMEV is very quite in operation and generally available on eBay at good prices. @HughF has just installed some humidity controlled trickle vents. For ventilation to be effective it needs to purge the whole space, so cross ventilation is really important. So if you have a bedroom at the front and bathroom at the back of the house that is idea. Trickle vents in the bedrooms but not in the bathroom, so the air has to go through the whole space. The doors need to have a gap (10mm) so the air has a passage way to move through when doors are closed.

I personally wouldn't, but your call

Slight update, this really hasn't been working too well, was fine for DHW in the summer, but so good at the moment. But found if I operated to two pumps together in manual test mode, I could deliver 1 to 2kW to the heat system. So have radically changed the control scheme to simplify things. Now just have two probes, 1 downstream of CCT's and the other on the top of the panel. The two pumps are wired to run together. Using a simple swimming pool control scheme. Ran out of sunlight today to test properly, so will see if the sun comes out tomorrow.

Reflective membranes need an air gap to function. Poor insulation for UFH, maybe not want you hear, install radiators.

The unit is really bigger than I need, but at the moment it's just outside short cycling and quite controlled. Short cycling for an ASHP is anything less than 10mins. Generally getting a good 15 min or more. Doing batch heating it was running for 4 hrs non stop some days. But the CoP wasn't any better. The big reason for running 24/7 is to displace the standby heating I was doing on our summer house, this required an electric heater set at 14 deg 24/7 and was using around 5 to 6kWh per day on its own. All of yesterday and so far today it's only used standby power for the thermostat 10Wh.

Reading between the lines of what you have said, it could be a single flow temperature ASHP. If it is, the flow temp is set on outset to 50 or 55. Basically the min flow temp for DHW. You then use a simple time clock and cylinder stat, to control when DHW is heated. The heat pump then either heats the buffer (control by a thermostat) or DHW. You would operate the buffer at a lower temperature via a thermostat. Your heating system would just draw from the buffer (piped as a 4 pipe) on a seperate pump which is controlled by room thermostat. Your cylinder and buffer thermostat would tie into P1 and P2 as volt free signal, to stop/start the ASHP similar to a gas boiler. So an older school unit, similar to what @joe90 had. Can work well.

Let's just go back to basics How are you heating and ventilating the property. The rooms in question what temp do you keep them at?

Bet the guys more confused, than he was before asking the question. If you are going to start suggestions such as heating MVHR, at least look at a data sheet, there is a heat loss of around 6kW, when you factor in the correct dT. The house is 390m2, so a ventilation rate will be 200m3/h or less. A post heater at 55 deg water flow rate and 212m3/h carries 2.5kW. so massively unsuitable for this application. That is practical terms would be a ducted A2A heat pump.

Obvious question - why not overboard the existing ceiling with insulated plasterboard, keep the head height and room feeling and reduce the heat loss? Instead of making a new ceiling structure etc... And making a room that will feel small.

Still using the weather compensation without any thermostat intervention to see what happens on different days. So yesterday was foggy in the morning and sunny in the afternoon but 8 degrees and by 6pm was down to 2 degs. We had some solar gain in the afternoon which warmed the front rooms of the house. So a couple of plots to show what happened This is the H&T in the hall, the heat from the solar gain moving into the hall, and slowly going back to the starting temperature over night. So couple of busy views, this is yesterday evening. The afternoon plot shows a slow down of the heat pump when the sun was out. The yellow is solar being generated. A 2hr window when the ASHP didn't add heat to the house. The evening when outside temp is 2 degs And this morning, you can see the run times getting longer. So although the ASHP isn't stopping when the room temp goes higher, it is sensing from the return water what is happening in the house. As for energy consumption the last 24hrs we used 12kWh on the ASHP and all auxiliary equipment. The previous 24hrs, with no solar gain and slightly warmer temperatures 9.5kWh Against a calculated heat loss of the garden room and house of close to 60kWh. So all things being equal a CoP of around 5. Which is inline with what to expect from the technical manual, running temp and

But don't connect to an ASHP, as the temps required are not a good match. Keep it simple

Artificial intelligence 0, Hard work checking through loads of shite on the internet and doing due diligence 1

But you are using MVHR, so your ventilation losses also increase if you increase flow rates, so you end up down a rabbit hole...

Question was Ventilation systems to passivhaus spec can carry 10W/m2 equivalent heat output. Any more than that the air smells burnt. Reference is from passivhaus institute. The original poster will have a heating requirement of circa 6kW over 390m2, so 15W/m2, 50% above passivhaus standards.

Yep

22 = (-)2 + 20 Buy new, mine was brand new, still in manufacturer box. Cooling you need UFH or fan coils, doesn't work with rads. Mine is as simple as it gets, ASHP, piped to 3 way diverter. One way goes to the cylinder, the other to UFH. Have a single thermostat to start stop the ASHP. Buts runs 24/7, on weather compensation. UFH has no pump, mixer or actuators. But go into the plumbing and ASHP sections, on the forum and have a read up. You need to do loads of reading up and decide what may work for you and ask questions.

You should be setting on something like wet concrete, tile adhesive etc, read your instructions - they will tell you how thick a bed you need to set it in.