JohnMo

That's all pretty rubbish from the supplier and manufacturer.

I've toyed with idea of PV directly connected to immersion. Can be done quite cheaply, then it's completely off grid. Certainly would then start to displace electric or gas heating used in the winter. The other alternative is MyPV, MPPT DC immersion. There's also an American guy on YouTube doing lots of solar stuff he has a link to a spreadsheet where you input your panel configuration and it tells which AC Voltage Wattage immersion to use to get best performance in DC.

I think it all changed when it was deemed a non competitive strategy, same time as the mains gas market opened up.

Why not passivhaus spec manufactured in the UK instead of imported? Keep your money in the UK instead of sending overseas. A passivhaus window only needs to an average of Uw of 0.8. So any good 3G will meet this. My windows were manufactured a couple of miles down the road. U values fixed windows 0.74, opening 0.84. Supplier had full responsibility from measuring to final install. Roof windows are by Roof Maker Passivhaus certified with a u value of 1.0.

New build the only way to go, you don't have to pay for the slates underneath.

Have found a supplier in the UK or are you importing?

She is always right... Been there, done that, got the t shirt

Bit dangerous quoting wikipedia. So much duff information on there. Agree it's so good we have have all these well educated (in wrong subject matter) running the show.

Not sure the maths is correct for model 1b The model may be correct if the circulation water went in the system hot and was returned cold, but if well insulated the losses during circulation would be quite small. For example I am circulating via a combi, so I can see when the boiler fires. On start of the circulation pump the boiler fires, within a few seconds it turns off. I am running a 30m loop for a couple of hours morning and evening, based on the maths I would be using around 300kWh a day. I am not.

Solar PV, but to reduce heating demand through winter, you may need thermal and/or a load of PV with a DC immersion(s), through a thermal store

We have similar. But you may need a post filter, we have a 10 and 5 micron unit. And UV just in case.

I would put ethernet to each room, the ethernet outlet can be combined into a TV socket. That way there is little or reduction in internet speed across the house. Then you have a good place to hook up a WiFi access point, one on each floor would give coverage for a good cost. If you have a blind spot easy to add. TVs are better connected to ethernet. If you don't understand there we site, why bother giving them money.

There is nothing difficult or complicated with heat pump technology, it been in air conditioning and fridges for decades. They may cost more than a cheap combi, but they shouldn't cost any more than a a half decent system boiler and cylinder. That's the issue, an open market would/should sort.

Agree let the market set the price, instead of incentives. Government funding leads to people people paying way too much for heat pumps etc, the only people winning are companies that take advantage of the schemes. The tax payer gets screwed every time.

Calor web site says they are?

Wow people have far to much time on their hands...and money I must being boring with a £2 manual switch, not sure how I cope.

Why not go hybrid and have both ASHP and LPG

but the actuator is supposed to modulate the flow to maintain the 7 deg differential between flow and return

I tend to think it's easier, from the stand point if anything goes wrong (insurance) and proving it has been installed correctly to BC. A registered installer can sign off and certificate, they can also argue the case for you, to BC, if they install per manufacturers instructions, instead of building standards; which tend to be completely different.

We have pine trees all around our get full of needles, real pain in ...

In the grand scheme of things, the aerogel adds can very little, compared to just using 60mm PIR.

All depends on the roof area. Deep flow for bigger areas

You mostly pay for labour. 'I don't want my build to appear that i have gone for the cheap(er) man made option" Then use the real thing.

I must agree with you, hence my first suggestion of dMEV. Very little running cost, good ventilation, as long as you have good cross flow. For way less cost than MVHR, you have condition based dMEV. Some light reading attached. Atamate_SDAR+Paper+2019+(1).pdf

As much heat (or more) will go downwards as up. Would not be very effective and cost huge amounts to run. I would save your money to spend on something else.