SteamyTea

I think the term you’re looking for here is greenwashing as those statements are neither linked nor relevant. Not sure you are right as the title is; Heat Pump vs Gas Boiler: Relative Climate Impact The link is climate impact.

So would I.

The main roof does not look that large, roof area is your friend with solar. Shading, of any sort, is your enemy.

Yes, and the same as 2,862 kWh of natural gas, gasoline, timber or coal. A kWh (not kwh) is derived from SI units for distance, mass and time. The real unit of energy is the joule [J] and is very small, the force needed to move a kilogram 1 metre. If you move that mass and distance in 1 second, then it is known as a watt [J/s] If you carry on doing that work for 1 hour, then that is a Wh. It is often easier to think of energy as gasoline or diesel in your fuel tank, and the engines power is the rate that you use up that fuel.

Write, not send.

COP 27 is not going to be of any interest to you then.

That may be true, and quite good for time of year. Not what your screenshot is showing. kW is power, kWh is energy, they are not, on their own, interchangable.

I think it is a west country thing, took solicitors 5 months to sort it out for me. An acquaintance has recently had a similar wait.

Small, achievable steps. It will soon start snowballing.

Thermal or moisture expansion and contraction maybe?

So halve the loads and hope for the best. What we usually did. I am not sure how elastic PU foams are, when I say elastic, I actually mean work evenly within the theoretical elastic limits. I think by the time you get to the nasty end of Young's Modulus, the point of no return has been reach and the material will fail rapidly. You only got to bend, or shock a sheet to see how easily it can snap. I don't know much about expanded and extruded polystyrenes, had to make some tooling for some once, but never even say the production process. They feel more compressible than expanded PU, but fingertips can easily be tricked by a softer feeling material.

So altitude as well.

Not that I know of. A couple of people on here have made their own. Basically a largish car radiator cooling fan, a speed controller and a manometer, which is just a pipe with two clear ends and some coloured water.

Spend 100 quid and make yourself a blower. Make your life easy as you go along.

So the humidity in the air had fused, then solidified. Which bit she in? This time a few years back the OAT went from 24⁰C to -7°C overnight, in Halifax.

I think you are right. Water can be 'enter' into brickwork and render just through wind driven rain, leaky downpipes and guttering, standing water etc. To my mind it does not make much difference to drying out what the render is made from when it comes to drying out. So treat internal humidity and external dampness as separate problems. Then, anything that is between the two will sort itself out in time. @darkrabbit Good luck getting an old house airtight enough to take advantage of MVHR

As usual, there is misunderstandings around heat pumps. Sized correctly, and run as intended, they are compatible to gas heating on cost. With any system that uses UFH, plenty of insulation has to be fitted under the pipework. You would not put your radiators outside on the wall, so why would you, in effect, do the same with UFH.

Don't they usually put the VCL on the outside in most of Canada? Different climate from ours in a lot of it. Most of habitual Canada is south of even me at Lat 50⁰.

There possibly are problems there. Usually they use 'aged' foams, which have already shrunk quite a bit. It may also be hard to tell if a slab has shrunken or dipped a few millimetres over a decade or two. Buildings do that anyway. A good SE should have designed for shrinkages I would have thought ( @Gus Potter, @saveasteading). What most likely happens is that the shrinkage is uneven, so some parts will pull away from the slab, other parts will be compressed a bit more. hard to tell without sawing a slab open, but would be fun to find out.

We used to work on 3% shrinkage when moulding polyurethanes. Some mixes where better than others. If you have ever wondered why new furniture has cushions that seem tightly fitted, and old furniture seems loose on the bench part, this is down to long term shrinkage. In the late 1980s, melamine powders where introduced into the mix to help with fire retardancy. This caused mixing problems (wear on mixing head and the pumps), this could make the curing inconsistent. An inconsistent mix causes uneven curing, adhesion failure and excess heat spots, all things that need to be avoided with sprayed products. When foam is moulded, or sprayed, there is an initial rapid expansion. As curing takes place, there is then a rapid contraction as the blowing agent (a gas) is released and thermal contraction takes place. Then a slow contraction takes place over time, usually months. One material we used carried on contracting at about 0.5% a year, for a decade at least. Long term contact with moisture, or even just high humidity causes polymers to break down. Excess temperature can cause initial softening, then brittleness. As much as I like polyurethane polymers, and there are literally hundreds on the market, I would be reluctant to use them as insulation. Great initially, long term they absorb about 10% of their mass in water, then, with thermal cycling, disintegrate. I have a feeling that a polyurethane is not allowed in aeroplanes as a structural element (skinned wings), though may be wrong on that.

It is always lunchtime somewhere.

I have heard that super glue in a lock stops the lock owner using them. Works a treat on car park machines.

How about not heating the house, then you can consider the keyhole as controlled ventilation.

I tend to agree. Some systems are going to be more airtight than others i.e SIP, ICF. Brick and block, on its own, is probably the worst there is. To a certain extent, airtightness has to be designed in from the start, not something to be put right later. There is a contradiction in the UK where the vapour control later is on the warm side i.e. inside. Then, usually structural elements and insulation, then a wind tight layer. It is too easy to think that the VCL is there to help stop air movement though the walls. Its main purpose is to stop high humidity air moving to a cold area and the water condensing out. After the VCL, the materials need to be more vapour open, this is to allow any water, or water vapour to be released. Here it is too easy to think that, as the VCL has made the inside of the building airtight, and the test shows it is airtight, the problem is solved. It isn't. Airtightness is also to do with making sure that cold air cannot bypass the the insulation, which will reduce its effectiveness. This is why buildings, especially timber frame ones, are wrapped in a windproof, but vapour permeable later. They stop the air movement but allow the moisture to escape.. So when thinking about mechanical ventilation, think of it as humidity control first, then how much energy it can recover. As a final year project I built a model of a room, then added mass to it so that the thermal stability could be measured. As I was studying active solar thermal, I had fans that blew air through the mass, or did not blow air though the mass, then measured the temperature variations, it was the data collection and analysis I liked, not the rocks and thermal inputs. If I was asked to look at the performance of MVHR now, the first thing I would do would be to build a physical model and start measuring energy input, temperature, humidity and airflows. Fairly easy and cheap to do these days (the Raspberry Pi did not exist when I was at university, so used a desktop burning 300W). Physical models are also essential to calibrate mathematical models.

You ca get an air test done on it. Either ask/beg a company that does tests, or make your own tester with a car radiator fan, manometer and a flow meter.