JohnMo

We just leave the MVHR to do its thing, windows open or closed. it only changing the air in a room every 3 hours. Not worth getting hung up on it. It's ventilation at the end of the day, not cooling.

I would tweek it down 0.5 degs at a time, leave for a while and check for condensation. You should be comfortable taking it down a couple of degrees. The lower running temp to will promote more heat uptake and a higher demand, so less cycling. It's a balancing act, so some trial error I am afraid.

Interesting email today, reference GivEnergy batteries only, if you're a member of Axle you get GivEnergy premium service included. You can invite GivEnergy users still, but no introduction bonus is payable any more - other makes of battery you still get the introduction bonus.

@Simon, beat me to it with the cylinder comments. For context on heat demand, NE Scotland total are 234m², with bed and living space at 192m² @-9 3.5kW. Not Passivhaus. So unless you are huge your heat loss calcs are way off.

They get your battery API, and control the export from it. Suppose it makes zero difference if it's energy direct from battery or PV. But you have to have a compatible battery to play and a smart meter

Next time you try to log in you will have go in via an email link. That link stays valid a few days only, repeat

Just shows why our grid pricing is completely screwed up! But I'm not going to turn away from a gift horse, while it's available.

I mentioned it before the weekend on another thread. Not far fetched. I used a referral and got £25, then on Friday an export earned £4.85 from Axel plus got paid by Octopus as well at 12p/kWh. They also state you will earn £10 per month. if you would like a referral code, just ask.

It's a bit like saying how much gas will I use. The log usage (cost) really depends on the house heat loss and how hard you need to burn. When we run our 6kW log burner, we run it at very low loads, one log at a time, so about 2 logs has burn time of 3 to 4 hrs, you may have a higher heat loss so run 3 to 4 logs and lots of air, so get through loads more than me. Cost also depends on how you source the logs. We have plenty of wood from cuts down down the build so zero cost, except my time. Way to many variables to give you a cost that is meaningful.

Nice trip hazard! If you need to it in the plant room, do you need to do it to every wet room, a fitting may leak while you out for the day? Do you have a floor drain? That maybe all you need. If not your hot swimming area will be difficult to empty anyway. Maybe over thinking it, our cylinder is above the kitchen, is it bunded area no, have I had leaks yes, were they an issue, no.

Wet rooms have tiles, main living space oak, bedrooms carpet (it's rubbish with UFH)

Explain? It close too which means what?

Are you all have open cladding, so you do get plenty of driven water in there? Otherwise a little OTT. I would be more interested to see how you are keeping wasps out, one small crack or warp they seem to get behind the cladding, then they start building nests.

And they are showing a 15kW heat pump. So unless you house is several 1000m² it's a bit large. Are you going for the grant or doing outside the grant? I have found very little difference in running costs doing DHW via immersion only. Which is outside the grant allowed method of heating. But direct immersion heating reduces install cost and cylinder cost. Heating design you have two options, but both options require a room by room heat loss calc, this allows sizing of room UFH array and radiator sizing. Option 1 is to run everything designed for the same flow temp. Then ideally run as a single zone. Option 2 run at different flow temperature. Then you may need zones, your smallest zone defines system volume. Which you need to add water volume to meet a 20L x min output kW if heat source. But a mixer driven by ASHP could have it's own WC curve so be operated as a single zone. No option above needs a LLH or buffer. Another option is to do fan coils in rooms upstairs and this gives you bedroom cooling (radiators don't), the UFH can do heat or cool anyway.

Just follow manufacturers instructions of chosen membrane. If you need additional belts and braces for airtightness, your primary airtightness measures need to be looked at.