JohnMo

What does a housing emergency mean? Walking about you see houses not occupied - that's one problem You see new houses being built and people living in them You see holiday rentals - is this a problem that should be addressed So exactly is the issue?

If you have single glazed windows you should have good thick curtains to help insulate, so this effect is killed off. Double glazing and triple glazing the effect would be minimised, the same would also be true for low temperature heating systems as strong updraft currents would not be there.

Or the long version https://migrationobservatory.ox.ac.uk/resources/briefings/long-term-international-migration-flows-to-and-from-the-uk/#:~:text=Net migration was unusually high in the year ending June,of migration in the UK.

No, it's just a cross flow heat exchanger. Hot air from house goes in one end of the exchanger (end A) and cooled air come out the other end (end B). Cold air from outside enters at end B and come out to feed the house at end A. Imagine a tube, inside a tube, the inside tube is the outgoing flow, the annulus formed between the tubes has the incoming flow. Both flow in opposite directions. If the tubes were long enough the temperature of the air at both ends of inner and outer/inner tube annulus would end up at the same temperature. As heat always moves to cold. If the heat exchanger was 100% efficient the mid point between end A and B would be at half the difference between inside air temperature and outside air temperature for both incoming and outgoings air streams. But because they are not 100% efficient you get a slight difference in temperature at end A and B between the incoming and outgoing flows. No magic going on.

6mm2 at least, but you really need to do calcs though. Armoured cable may be better as well with MC4 connections.

Your building heat loss is the same irrespective of number of rooms or number of UFH loops and or number of radiators. A well insulated house, really doesn't need bedroom rads, it will get all the heat it needs via the downstairs heating. I heat my 192m2 and 26m2 garden room from a 6kW ASHP and it's really too big. All depends on how well insulated and how good your airtightness is and the ventilation strategy. You need to do heat loss calculation first then the heat pump size follows.

The only work being done is done by the fans to move the air. https://www.open.edu/openlearn/nature-environment/energy-buildings/content-section-2.3.2

Never seen the point of them on an external wall, even on our 1830s house I moved then to internal walls.

So about 7,000kWh export required if you can get 14.5p or 22,000kWh if you get 4.5p to break even - Really not worth the effort or hassle. The first figure is close to 1.5 years full production being exported, which never occur. This month so far, just about zero exported.

Nothing wrong or cheap and nasty about any of the below. Look at city plumbing or similar. Panasonic 5kW £2300, 7kW £2800 LG 5kW £2100, Ideal 5kW £2500, Grant 6kW £1900. £10k they have seen you coming and are ripping you off. Simple monobloc is all you need, others on here state that Panasonic are great bits of kit. You can pay an extra £2k for Vaillant if you want, but no idea why people do. Mine cost £1300 vat included, last year, does heating and cooling out the box, is cheaper to run than my gas boiler - what's not to like. My Ideal 210L slimline cylinder was £900 incl vat.

And a bunch of money to pay them upfront, which would take umpteen years to get back, no point. Plus I believe if it's not a new build you need the structural engineer report to certify your roof is suitable etc.

Just look at the prices yourself New build so heat loss shouldn't be huge so assume a 6kW - about £2500. Cylinder £1000, should come with full safety group and expansion and maybe a 3 way valve. Feet and Flexi hoses for ASHP. Some 28mm pipe either copper or Hep2O. UFH manifold, 16mm UFH pipe and staples and a decent thermostat. That's the full shopping list just about. About £5k should do it.

You could explore this https://coolenergyshop.com/collections/air-source-heat-pumps/products/activair-3kw-indoor-air-source-heat-pump Tee it into you MVHR pipes that go outside, you would have to take a proper look to see if it works. There are no noise figures so that would need to be understood and it's a little vague on cooling, it seems to have an icon but no other mention. Then connect to a fan coil radiator.

Here is a typical schematic showing the flow paths. No heaters attached to my MVHR. But as I mentioned to gain 2 degs at best more likely 1 Deg or less) not worth the effort, for the marginal gain in CoP.

Just looked at a photo of the temperature when it was 3 degs outside outflow are was at 4 ish. It's a cross flow heat exchanger so the outgoing air will be cooled to nearly incoming. Incoming air will be heated to nearly the same as the air being extracted from the house. Actual temps were OAT 2.9 Extract to outside 4.6 Room extract temp 19.8 Room supply temp 18.9

They want us back in the EU = unlimited immigration

SNP, wants almost unlimited people coming into the country, they have been in power for donkeys years and anything not right, is the UK government problem not their and of their making. SNP have frozen council tax for about a decade and wonde why councils have no money. Sooner they get voted out the better.

Not really sure how they modulate the power to match what's available? Maybe they vary volts to keep things in balance - could be talking rubbish. @ProDave maybe able to shed some light on it as he built his own diverter.

Different system, the one the OP is referring to takes tap water through an indoor heat pump unit (W2W or water to refrigerant) and then said water is routed to drains never to be seen again. Many (100s) m3 of water goes to drains system over a summer period even when there is a hose pipe ban in force.

Don't ask?

Simple facts are MVHR airflow rates are way to low to have much or any effects on room temperature. You are only exchanging the air once every two the three hours. Read above, plus that form of cooling works by adding water vapour to the air to cool it down and play with dew points etc. but in the UK generally the humidity in the summer is high so effectively, it's not much use. Water based Aircon is a waste of good water unless you can recycle the water via buffer or something. If you can't do a split Aircon or traditional heat pump, I would look at through wall Aircon. Basically two duct holes in the wall and everything sits in the room like a radiator. Not a recommendation just the first site I came to https://www.nationalheatershops.co.uk/c/ptacs/

Yep - maybe, would that sort of radiator looks daft in the wrong orientation? Do it and report back (you are not wanting to here the answers being given above) - but would the brackets that hold the radiator on to wall, even work in the wrong orientation? Or just buy the correct radiator for the job. They are available, we had them in our last house. Not that expensive, if you shop around.

I did do some calcs for something similar, and a 2 Deg uplift in temperature is worth approximately 0.3 CoP increase. Looking at my inlet and out temperature difference on the MVHR there is only 1.9 degs difference. So we are looking at a CoP uplift of 0.3 at best. There are a few practical issues The condenser wraps it's self around the ASHP in an L shaped, so the MVHR outflow would only hit some some parts of the condenser not all. So even if the air was hotter than outside air the impact on the condenser maybe much smaller than anticipated. Getting the MVHR outlet and heat pump inlet in the same space may be difficult or not practical. Or just look a mess. My conclusion was it really wasn't worth the effort for very marginal gains.

Was it installed via the MCS grant scheme?

Can you not surface run it, instead of underground?