JohnMo

Check the internet most are out there somewhere

I would get someone to check. Try and find the manual see what it says.

Correct Be careful as different manufacturers label differently. You need to look at the datasheet to make sure it's output is ok at your lowest temperature. Would question your design basis. It's more normal to have -3 outside and 20 to 21 inside except bedroom at 18. You need head room to do hot water. Allow 3 hrs. So working with 4.2kW, 4.2kW x 24hrs, then divide that total by 21 hrs, this should give you the size you need. Replace the 4.2kW with a better design basis. They don't restrict flow so zero.

The white vertical pipe belongs to your your gas supplier or the gas network supplier. To move is few stages. The network will have meter move forms you complete and pay a chunk of money to them. They make an appointment. You then get your plumber to disconnect the house from the meter. Network team arrived, move meter and replace pipe as required. Your plumber comes back to replace or run the house gas pipe and does commissioning checks. Budget a month or two from filling form in to being commissioned. All work can normally be done in a day, just getting everything aligned takes time.

They are pretty quiet, and WAY better than trying to sleep in a hot bedroom. My wife has one in her massage room where she likes silence, and doesn't seem to bother her. We have a Myson iVector. Winter you most likelihood will not need them. In use during summer the cool should fall to the ground floor, aiding the UFH which is also in cooling mode.

Sorry have you been anywhere near an MVHR unit? Have you tried to remove the heat exchanger, they are a really tight fit. Why to ensure there is no bypass between sides. Not sure how anything would bypass the between inlet and outlet. Testing for a bit blocked, is called annual maintenance. Removing the HE to flush through and remove debris etc.

That is the best advise. They will take the same flow temp as your UFH, so no mixers are needed. Run everything from the ASHP circulation pump, all as a single zone, no room thermostats needed.

No, your house heat loss is what it looses. If you just have UFH and no radiators it still looses the same amount of heat energy. Radiators everywhere and no UFH it still looses the same heat energy. Put in provision for electric panel heaters in bedrooms. At 180m² house and well insulated, your heat loss isn't going to be much more than 3kW, so you should be on the smallest heat pump anyway, any bigger than 6kW, welcome to big bills from short cycling.

That's not how MVHR works. Extract air only goes outside, it goes via a heat exchanger, air going out and air coming in, are on different sides of a heat exchanger and never mix. Air taken from the kitchen ends up outside and cannot go via other rooms or be distributed around the house.

So tell us about a normal (well maybe not that normal) house that is pretty airtight, has MVHR, triple glazing, ASHP, also made of ICF, and how the hob and using it. actually requires a ducted extract. What advantages we get to IAQ overall and for the 30 mins a day you may spend cooking? Most kitchen cooking hoods are set way to high from the hob to be effective, either at extracting or recirculating. So in most situations the bad stuff just bypasses the hood anyway. Main difference from anything commercial, is the fact no one spends that much time actually cooking every day. So circumstances, cooking temperatures are not compatible. Understand the need in a commercial kitchen, but not sure I follow the thread in a residential property.

Don't be caught with the installer adding 10% to his materials. When you are buying lots of sheets of plasterboard for example, that can be quite a few sheets that do not even get touched - been there got the expensive tee shirt.

What do your drawings say? That's what the builder should follow nothing else.

The sap report has all insulation between the rafters at 40mm thick.(Layer 3) Then a layer of 150mm insulation below that is layer 4, there are no rafters or wood present, so this must be below the rafter. There is no insulation above the rafter. Layer 5 and 6 are the wrong way around?

Just paint the ceiling near the sofa a slightly darker shade of brown. Now you are finished. Here to help 🚭🙂

Perhaps you could heat the whole house from the oven? 😜

Not that I noticed. As said we barely use the cooker hood, so regen are few and far between.

Leave them alone, all wood splits as it dries out. Look at any old oak house.

Could it be the power to garage has just tripped off? If it hasn't would it not be easier to just kill the garage power at the house consumer unit? But not sure it will help anyway either killing power or cutting wire. Obviously no side door to get access via?

Grease filter goes in dishwasher. Carbon filter goes in the oven to be regenerated. As said before we hardly use the extractor at all and we find zero need except for really smelly stuff. Our kitchen MVHR filter sock (after 6 months installed - top is the outside the duct side, bottom is inside, showing dust ect from the room. Why do we need to question the norm? Where is your evidence that a normal house (with MVHR or other suitable ventilation system) suffers from poor IAQ. Most houses don't even ventilate correctly and suffer mould, which I suspect is way more hazardous to health - than an extract on recirculation with decent grease and carbon filter, positioned at the correct height for effective performance, so you don't need to run the fan at full speed. Everyone is free to do what ever they feel is correct for them. Personally think everything is getting OOT, I have said my view, so will leave it there.

What you haven't mentioned is how the puppies run that are connected to the heating coil. If they go upwards or horizontal you will get thermal gradient and it will extract heat from the cylinder on a continuous basis as you describe. A photo of your cylinder would be helpful.

This what Passivhaus say on the subject 05_extractor_hoods_guideline.pdf

No they pocket £7500 and charge you another £ lots of thousands, if you are not careful. Unvented cylinder was bought last year from City plumbing, it was about £805 plus vat last August. Came with 3 port valve. ASHP, is Maxa i32-V5. Sold normally in UK by Viessmann (around £4500). Billy bargain from eBay, after plenty of research, £1300. Came new in box and original packaging from Italy via a UK company. Need rubber feet, flexible hoses etc as well. Bought all that in 2022, but prices aren't much different, around £200 UFH came from outsourced energy shop. (Prices are now cheaper than I paid) Current prices IVAR 8 port manifold £163. 2 x 300m pert-al-pert £560, plus a few other bits and bobs £100. You can claimed back, so prices above are plus vat. Except ASHP which came from eBay so vat paid.

Even without the the grant with careful shopping, keeping the ASHP install really simple for best efficiency also, you install unfunded sub £5k for everything. Ours install as it is at the moment (as simple as it can be) would have cost us about £3100 including the UFH. It includes a 6kW ASHP, 210L UVC, 195m² of UFH and manifold a bit of pipe and insulation. Have a thermostat in the house and it switches between heating and cooling. Our neighbour just paid £4k just to replace a gas boiler.

Sorry how is that "keep it simple" a thing but simple. Easy answer - Keep it simple - don't fry everything. Then you don't generate the pollutants.

I found that when I was looking. Thanks for the drop info, have ordered a bottle.