JohnMo

The additional heating is either a relay output to fire an immersion in the central heating system, or an additional boiler. These can be needed for extreme weather cases, where the heat pump cannot cope.

As @Nickfromwales is aware my real life view of woodcrete ICF is very different from his. We have never had any water come through the walls, no damp issues period, 5 years and counting since the walls went up. Yes we did parge coat to the inner wall for airtightness, 2 days work. We then attached 50mm battens (service void) and then plasterboard. Out of all the systems (Durisol) was easiest for me, no special props required etc. Just simple had tools.

Forgot to mention DHW, this was to be by immersion only. Have rethought this, as all the hardware and cables are in place, to switch the 3 port valve. But gone a much simpler layout than previously. Immersion is standalone and not connected to heat pump at all. Any issues with heat pump, just flick immersion on. Routing was always difficult to sensor probe from heat pump to cylinder but that has been solved by repurposing a cable or two not in use, that running through the house. But includes the cable I was going to use for the smart grid switching. One problem solved, one created.

Jobs done today The feet I bought to go underground the heat pump were 1m long, so trim them down to a more manageable length of 800mm. Moved the heat pump from patio to closer to the final location. Used a simple garage trolley located under the manufacturers pallet. Next job is to cut off the pallet away at the light end (condenser end) and affix a foot. This will give something to lever against so when in final position the remaining pallet can be removed and the other two feet added. Completed all wiring as far as possible. So 3 core cable for power, 2x0.75 screened cable to outside unit and further 2 core to the smart grid connection (can't complete this as cable from house is currently connected to other heat pump. I heat the summer house as part of the same zone as the house, it runs at 18 to 19.5 normally, but sometimes we need it warmer, so I normally use a thermostat to trigger a second setpoint for the heat pump, which works fine and floor just buffers the heat. The Hiaer unit, I will utilise the smart grid connection, and set a 2 Deg uplift in flow temp when the connections across terminals for SG2 (EVU signal) are closed. The same connection can reduce the cooling flow temp should I need it. Also made some covers out of excess OSB from the house build, to cover some gravel I need to travel over. Looks like next weekend to do the heat pump change over.

You can cover this in another thread rather than clogging this one up. Just need to start it.

Trouble I have answering this thread is the heat pump control is being somewhat taken over by another 24v system, so it's a can of worms. Simple made difficult.

When I did my new build I priced up Fresh-R, but got push back from building control on flow rate not matching building regs. But the concept is good and can be made to work with ordinary MVHR units, using cascade ventilation. So extract from all wet rooms, add air in a central location, so it passes through other areas before being extracted. Between room fans if layout demands it.

No chlorine, so not really pool type water. Will monitor pH and drop and top as needed to that in check

No, but also not using any chemicals either, so no need for titanium heat exchanger. ASHP not connected yet. But when running, modulation down to 1kW should mean it just runs, so should never see the 14W on its own and should be accounted for in the running CoP.

It's just being repurposed - the 6kW unit will be used to heat 1700 litres of water (hot tub). Just been outside with dog, while I was waiting about I was feeling all the edges of the metal, everything seems nice and rounded off, nothing sharp at all. 90+kg to move about, that will be fun - not. Set up the controller this afternoon, only thing I can't do is load the WC curve, because the unit doesn't see the flow and return temps as no outdoor unit is connected. Had a look at the electrical draw The whole wiring centre and controller pulls a continuous 14W.

MVHR dies summer bypass automatically cannot change it, not sure how it helps, unless it increases heat demand, which not sure below the back pocket

Nope not enough cooling effect. UFH in cooling mode leads to a nice house

It's minimum modulation is near 4kW, house demand is only 3.5kW max. Normal run of things I wouldn't change it, but we have just bought a wooden hot tub, so will repurpose the old unit to heating the hot tub, instead of the normal wood fired heater. So get a heat pump more appropriate to the house demand. Should make a decent dent in running costs, with better CoP in summer and winter, for very little money.

Didn't answer fully before

There is the inverter controller outside but I think the indoor wiring centre controls most things The relay is for cylinder immersion control. You can drive a couple of secondary pumps, mixer valve, 3 port valve etc. plus lots more.