JohnMo

So the dMVHR you are proposing to use work in pairs, one extracts and the second one applies air, they do this for around 20 secs and then swop. The room should remain at a stable pressure, not negative or positive. So long as you have 2 working as a pair you are ok. Hob extract, is the danger zone, they will pull huge amounts of air from the room. If you are quite airtight (you are installing MVHR, so should be) you will depressurise the house enough to overcome the flue effect of the stove and instead of leaking air in to fire and flue seals, it will leak combustion smoke and CO into room. CO is a silent killer.

It's a complex foundation by normal standards, due to being on the side of a hill. There's also whole heap of horizontal rebar below that, plus another cast vertical section 500mm wide of concrete foundation to go at the front of the house. The vertical rebar is to join the two sections together. Then more rebar (2 layers) and a 200mm cast concrete slab. 3 days later Then 200mm.of insulation, UFH and another 100mm of fibre reinforced concrete instead of screed.

We used a pump lorry - we had a stretch of 30m with no real access any other way.

This sounds like a can of worms. If you have MVHR you really need external only air supply to stove. As mentioned extract in same room isn't allowed. Extracting hood will just lead to room depressurised and the stove spilling combustion air into the room as soon as door is opened. Even if you have hood in recirculation mode, you will still have kitchen extract for the MVHR. Don't be concerned, I rarely even use our cooker hood - MVHR does the job 99.5% of the time. Your issue isn't the cooker hood it's the fire. What is a ventilation fluxo you refer too? The air supply to stove is through wall so takes outside air to use as primary and secondary for combustion. It ensures stove doesn't use room air for combustion. It doesn't remove any need for room ventilation.

Service battens tapered edge plasterboard and dry line.

And a massive building trashed. All from a AA sized battery or two. They were still spraying water in the place the next day.

Auto correct - should have read.

Is it going to make any meaningful difference? Battery inside or outside attached to house is a part of full rebuild of house, especially if you get a couple of fire tenders emptying their water

To add to the above - I have G3 cone filters in the extract terminals, have not need to change an extract filter in the MVHR they come out clean and are reinserted. The cone filters are now hoovered every 6 months and replaced yearly. The intake filter really depends on season and location. Generally I hoover 6 months and replaced annually, but depends on what I see when I take them out. Bearing in 5 years none so far. Service costs about £30 a year for 2x units. Running costs as above but reduced as I have battery and plenty of solar. Heating costs reduced by a bigger margin. MVHR was mandatory due to airtight score in Scotland. So zero options on to install or not.

Wise words. But seems to the way of things, let's missed out the key steps and try to short cut, then end up spending more time and money to get yourself out of a self dug hole.

Or get some solar and an immersion - nice hot baths/showers unaffected by global energy costs.

How quickly things can change!

Scottish heating oil doubled in cost over the last week or so. Was the cheapest, now the most expensive way to heat.

I came to same conclusion. Good enough for nearly all cases. If the pump can't cope or is close to not coping you will be installing an additional pump anyway, so keep.it easy.

If you are at planning stage and not warrant stage, just say ASHP, solar, MVHR? But the architect should be doing this form for you as part of the design and application process This form is nothing you should be paying for, until you get to warrant and then the information comes from as designed EPC.

Is that on an EV tariff? No ev here

Ask your architect - he should have standard words. If you are at planning stage in Scotland, that should be all that's needed. When you get to warrant stage you will need 'as designed' EPC and once built that converted to 'as built'. It's a tick box exercise at planning stage. But if you say your going airtight, they will expect to understand your journey to get there and what products you plan to use with datasheets.

Just did a comparison, the chart above reads slightly lower than a full calculation (500Pa less) 0.9m head, instead of 0.87m.

Loop length 95 x 90Pa, which s 8550Pa or 0.87m head. Have UFH flow meters open and pressure drop through manifold is small. Plus your pipe, filters and strainer etc.

Really depends on what the OP wants

Battery - so only pay 15p max for electric. But air fryer most evenings instead of a big oven (only two of us)

Do everything a tight fit and foam any small gaps, rather than wholesale foam every piece. I did every joint tight and knocked in place with a piece of wood to spread load and a mallet. Go around edge slowly to insert square not at an angle. Ideal is it needs no foam, but sure that is realistic. Then I taped all the joints.

So has most other companies if you want any fixed price tariff. But luckily I fixed in September for a year. Hopefully everything will have stabilised or normalised by then.

Sorry confused - the way you want to operate isn't efficient anyway. So are you fussed about efficiency? You seem willing to spend thousands to get a poor efficiency system anyway. I'm not even convinced you need you need two boilers, but hay ho. I keep looking at this thread and I shouldn't.