SteamyTea

Too many bridges, a large marine diesel, with turbo chargers in it, small propeller to keep to the speed limit. There was someone else a few years ago who was building alongside the Thames up that way. Can't remember what happened to them.

Welcome A watertight one.

Probably had a traumatic incident at school.

More likely to have a police register built in. Our very own @Pocster has designed his own hardware that uses a webcam to part automate all these processes.

About time. Every combi boiler I know of has a slug of cold water, followed by a boiling one, then it settles down, till someone opens a tap. All you need is 3 sheets of yesterdays newspaper, and they are to wipe your fingers clean with. Does their colour white cost more than my colour white? 'Rich man sweatin' in a sauna bath Poor boy scrubbin' in a tub Me, I stay gritty up to my ears Washin' in a bucket of mud' Elton Bog, Bernie Tampon, Hercules, 1972.

Another thing to add in is the local weather regime. There is little difference in mean temperatures across the UK. There is quite a difference in how they are distributed though. So West Cornwall may have a similar mean temperature to Hull, but the extremes are closer to the mean. Sunshine hours are also different, which can make a difference to cooling costs. 3 years ago when people where paying 2.5p/kWh for gas and 12p/kWh for electricity, there was a case to be made for just meeting building regulation levels. But different now that gas is 7.5p and electric 30p. And then there is airtightness. More energy can be lost through this than through walls, floors and roofs. The much mentioned Jeremy Harris spreadsheet was originally designed to compare price comparisons to help establish best value for money. Easy enough to use it as such, just fill in different numbers and see what it churns out. One word if caution, if anyone says that "it meets building regs', or 'airtight houses overheat', walk away from them, they will do a bad job.

Is this an infomercial?

Worth looking here as a starting point as it can be modelled as a viscosity. All the workings will be down at the bottom left of the charts. https://www.engineeringtoolbox.com/air-absolute-kinematic-viscosity-d_601.html I heard you have a semi.

I really don't know, but with the relatively low flow rates and assuming a decent installation, I doubt it makes any real difference. If flexible ducting was dreadful, it would not be used much. I think there is also a preference for rigid ducts as that is what is used commercially, and a lot of the MVHR people are old commercial installers.

Yes, that is the primary defense against condensation, keeping above the dewpoint. Also spreads out any cold bridges. It does diffuse, and quite rapidly, but it also follows any temperature gradient. I was trying to set up a couple of IR thermometers to log wall surfaces, because I have noticed that my inner walls are a couple of °C lower than the ambient temperature, and the outer wall a couple of °C higher than OAT. Probably why there is a default R-value for the air film. I keep meaning to research this whole area more, but I need to feed the starving Emmets and we are getting busier as summer approaches.

You can unscrew a bookshelf from the wall, but you cannot unscrew a pregnant wife. Or send back to Screwfix for a refund.

You can get PIR boards without the foil vapour barrier. https://www.secondsandco.co.uk/product-page/pir-boards They would probably be OK as by the time the VCL/MVHR has done there business, and the fact the PIR is on the low temperature/Lower RH side, there would be virtually no mass of water vapour to condense/freeze. This does raise the question if what sort of roof you want to fit, Warm (would be my choice), Cold (just why) or the Hybrid (horrible). The reason this makes a difference is because it can change where the effective moisture release areas are. My feeling is if you control ventilation and heating, which is really just another way of saying keep the internal RH as low as comfortable, once the building has dried out fully, you will not have a problem.

Um, yes, or no. Raoult's Law Years since I studied this properly, but seem to remember that the general idea is basic. When looking at this sort of stuff I use statistical models, then the real risk can be quantitative.

In the UK where we generally have a greater relative humidity inside than outside, and generally have lower temperatures outside than I side, moisture needs to travel outwards. This is generally achieved by modelling it via the partial vapour pressures. All that means is that as long as the associated temperature and RH barrier allies water vapour to move outward, then there is generally not a problem. Any condensation within the structure is expected to evaporate and travel outward in a short space of time. The VCL is placed inside because that is where the warmest and highest RH air is, ventilation (MVHR) is used to replace this air with lower RH air. So when looking at the different layers, you need to know the vapour transmission rate and make sure they can allow more vapour though then as they get colder (outside). The theory is based on the ideal gas formula PV/T where P is vapour pressure rather than absolute pressure. V is obviously a fixed volume and T is absolute temperature. (A lot of thermodynamics is based on modifying the idea gas formula)

Partly, why it is best to scribble out anything that makes it identifiable. The other problem is that search bots trawl websites and pick up on names address, phone numbers and payment card details, which is a problem.

That is a very difficult one to answer in isolation. Condensation risk analysis is a huge topic, but one that will need explaining sometimes. My view is that for any material that can absorb moisture, AND then give problems, you need a VLC.

I’ve noted that many peeps seem reticent about posting their plans so I haven’t posted so far, but I don’t see why not. Because we like to rip other peoples designs to shreds, then redesign it as the place we want. I usually never comment on the layout, unless it is hideous (only commented once). That will be 'to' not 'too', or so I am told. You seem to be getting a good handle in it, so what ever you make will probably be a better standard than an off the peg design.

Welcome Helen. Have a look at both wall mounted Air to Air Heat Pumps and through the wall heat pumps.

Can you post up some dimensioned sketches of what you want to achieve. Each thermal element does NOT have to meet building regs, so some areas can overcompensate for weaker areas. It all comes down to surface areas and U-values at the end of the day.

Embrace wooden buildings for the sake of your health and the planet's The burgeoning use of wood as a building material is a path to more sustainable construction, and it may have psychological benefits too, finds Graham Lawton By Graham Lawton 6 June 2024 The Marcadet Belvédère project in Paris, a low-carbon development where the existing base has been restructured and the new elevation built in wood Stora Enso partner: WO2/©L’autre image A few years ago, I wrote an article about new uses of wood, including as a sustainable construction material. It was a surprise hit. Since then, we have covered wood technology as often as possible. So when I was invited to Paris to visit two state-of-the-art wooden building projects, I jumped at the opportunity. One is a refurb, the other brand new, but both are built almost completely from wood and have enviable environmental credentials, as well as being aesthetically stunning. I have sung the praises of wooden buildings for years, but had never been inside one. Now I have, I am smitten. My first port of call was a city centre development called Marcadet Belvédère, a former parcel terminus for the French railway network overlooked by the Basilica of the Sacred Heart. A long-abandoned eyesore, the developer WO2 is adding five extra storeys to the concrete shell to create office space. The new storeys are mostly made of cross-laminated timber (CLT), an engineered wood product that rivals concrete and steel as a structural material, but with a much lower carbon footprint. According to WO2’s director of engineering, Laurent Petit, the wood the firm uses – sourced from Stora Enso in Austria – brings significant environmental benefits. Over 50 years, Marcadet’s total emissions will be half of what a traditional concrete and steel refurb would have belched out. That is largely due to the materials, but also reduced running costs. “When we started to build in wood, the purpose was to reduce the carbon footprint, but then we discovered a lot of other benefits,” Petit told me. CLT is 80 per cent lighter than the combined mass of concrete and steel, so there is no need to reinforce foundations at financial and environmental cost. It is quicker to build with, requires fewer trucks and less heavy equipment to be brought on site, and has useful thermal properties. A standard building has high “thermal inertia”, meaning it takes a lot of time and energy to warm up and cool down. But in a CLT building, the moment you start the heating, you start to feel the warmth in the atmosphere, says Petit. Cooling is less straightforward, but at Marcadet, this is aided by the plants and trees in the building’s rooftop garden. When it is hot, these evapotranspirate water from the soil and hence draw out heat from the rooms below. There are wider thermal benefits too. During a heatwave, concrete soaks up heat and radiates it out at night, keeping the city sweltering. Wooden buildings don’t do this. Deadly heatwaves are a growing problem in Europe and are especially dangerous when there is no respite at night. Wooden buildings can burn, of course, but Marcadet shouldn’t. “What burns in a building is the furniture, not the structure,” says Petit. “Yes, wood burns, but ignition is slow and almost never happens.” Marcadet is further protected by a sprinkler system pioneered in art galleries that sprays minuscule droplets of water. These don’t quench the flames directly, but cool the fire down. The droplets instantly evaporate and the latent heat of this process helps put out the fire. Next, I visited an other WO2 project. Arboretum, on the western fringes of Paris, is a stone’s throw from the skyscraper jungle of the La Défense business district, but a million miles away in spirit. “It’s the largest wooden office project in Europe,” says Laurence Desmazières at investment fund ICAWOOD, one of the project’s backers. Arboretum is a campus comprising five new low-rise offices set in parkland. The buildings are made largely of CLT, which, as at Marcadet, means the project has half the lifetime carbon emissions of a standard new build. Inside the buildings, the wood is deliberately and beautifully exposed on walls, ceilings and columns. “You can feel the wood, touch the wood, see the wood, smell the wood,” says Desmazières. “Wood also has very good acoustics. The idea is to offer nature to people inside the buildings.” It isn’t just aesthetically pleasing. Contact with nature, even via the built environment, has proven health benefits. “Being in a wood environment helps from a physiological and psychological standpoint,” says Desmazières. “You’re less stressed and you sleep better.” I would certainly swap my office space for a desk surrounded by gorgeous wood. In France, that will increasingly be on offer. Recent laws demand that developers calculate the lifetime carbon footprint of any new building. Those that exceed a certain threshold won’t be given planning permission. That is sending firms scurrying to source greener materials such as CLT, says Desmazières. “Wood has great days ahead.”

"All models are wrong, some models are useful" I like to take the reductionist view, break down the parts until they are easy to calculate, then intergrade those results into a coherent mathematical model. Yesterday's More or Less had a bit about the sampling size to get accurate results. It is worth listening to the first 18 minutes and 40 seconds to get the the interesting bit. The easy way to test a model is to change 1 parameter and see what the results are, then change that parameter back to the original value, and change another. Keep the results and use them to create a distribution chart.

I am not sure, but if each component has a certificate/documentation i.e. the correct C for timber, the correct number for OSB, proper adhesives etc, then will the sum of the parts be, in effect, be your warranty?

They do, usually has Celotex written on it. I know a surfboard manufacturer than buys in sheet PU from Mexico. The two UK towns that used to be the foam moulding places were High Wycombe and Glossop. But it is a while since I was in the industry.

Or better still, pick a thermal performance, then find a way to build to that price. Easy to save £60k by getting sensible kitchen and bathrooms, rather than showroom fancy ones.

Or better still, pick a thermal performance, then find a way to build to that price. Easy to save £60k by getting sensible kitchen and bathrooms, rather than showroom fancy ones.