Jeremy Harris

+1 to the above, it would be a massive PITA to glue them all together into usable sizes with LE foam, then tape them. If you really have got hundreds of them, then you could look at setting up a flat bench with some polythene sheet (LE foam doesn't stick well to polythene) and then perhaps make up some sheets that were the right size, it really comes down as to whether the cost of the LE foam, the tape, making up the bench to assembled flat sheets and your time works out cheaper than buying new stuff.

I hope that what comes out of this are regulations that are more specific, approval processes for both materials and people that cannot be fudged and fiddled the way they are at the moment and an enforcement system that is actually fit for purpose. Currently anyone who knows how to game the system can do so with near-impunity, as had been shown time and time again with the compliance failings by major construction companies that get regularly highlighted on new developments, and I strongly suspect that's just the tip of the iceberg, as many of the compliance failings will be hidden from the final customer. One clear problem in my view is that big builders can buy their own inspectors, so there is a very clear problem with a clash of interests. Any building inspection company that makes life too challenging for a construction company, by insisting they follow the regulations is likely to lose business to other building inspection companies that take a more relaxed view, in order to make sure they win future contracts.

I get the very strong feeling, based on the high shipping costs from Total Home, (more than the shipping cost from Sundthus in Denmark), that a faulty unit may well end up being shipped back to Denmark for repair even if bought from them. Looking at the shipping cost difference, my best guess is that if buying from Total Home you end up paying both the shipping from Denmark to their depot, plus the shipping from there to your home, as that just about adds up to the right figure. We had a similar experience when our first boiling water tap had a manufacturing defect (an internal hole was drilled in the wrong place). We had bought the unit from a UK supplier, but ended up having to deal with the manufacturer in the Netherlands when there was a problem under warranty. In that case they initially wanted the defective unit shipped back to the Netherlands for inspection/repair, but I managed to convince them of the cause of the defect with some close up photos, that clearly showed the hole drilled in the wrong place (not easy to take photos deep inside a tap!). They were pretty good and shipped me a replacement tap from the Netherlands directly, and didn't want the old one back.

I see that the initial review by Dame Judith Hackitt has stated the blindingly obvious to anyone that has dealt with building regulations and building control in the past couple of decades: http://www.bbc.com/news/uk-42392138 Her interim report can be read here: https://www.gov.uk/government/publications/independent-review-of-building-regulations-and-fire-safety-interim-report

The problem with trying to move heat around with air is that you need to move very large volumes of it in order to have any appreciable effect, simply because air has such a low volumetric heat capacity. Say you wanted to shift an unwanted 500 W of heat out of the house, and that the temperature differential you were trying to correct was 2 deg C (the house is too warm by 2 deg C). The volumetric heat capacity of air at 25 deg C is about 1210 J.m-3.K-1, which is around 0.3361 Wh.m-3.K-1, so if you wanted to move 500 W of heat in one hour you would need to shift just under 3,000m2 of air to lose 2 deg C. That is about 10 times more air than our Genvex Premium 1L MVHR can shift on full boost. Because the Genvex has an in-built air to air heat pump, we can deliver fresh air on a hot day at around 12 deg C or so, and that does make a slight difference. It's nowhere near enough to compensate for significant overheating, but is OK for a tiny bit of comfort cooling if we can restrict the incidental/solar heat gain a lot.

Not sure how thick the slab is, so I'll assume 100mm - if it's different it's easy enough to change the thickness and recalculate. From the bottom up: 100mm thick concrete with a λ of ~1.5 W/m.K gives an R value of 0.1m * 1.5 W/m.K = 0.6667 m².K/W 90mm thick PIR foam with a λ of 0.023 W/m.K gives an R value of 0.09m * 0.023 W/m.K = 3.913 m².K/W 20mm UFH boards, λ unknown, so assume same as EPS 200, 0.034 W/m.K gives an R value of 0.02m * 0.034 W/m.K = 0.5882 m².K/W Assume 4mm foam underlay with a λ of 0.034 W/m.K gives an R value of 0.004m * 0.034 W/m.K = 0.1176 m².K/W 6mm ply with a λ of 0.15 W/m.K gives an R value of 0.006m * 0.15 W/m.K = 0.05333 m².K/W 16mm bamboo with a λ of 0.15 W/m.K gives an R value of 0.016m *0.15 W/m.K = 0.1067 m².K/W Adding all the R values above gives: 0.6667 + 3.913 + 0.5882 + 0.1176 + 0.05333 + 0.1067 = 5.4455 m².K/W Taking the inverse of the R value gives the U value: 1 / 5.4455 m².K/W = 0.1836 W/m².K For bonding foam together, then any low expansion gun foam will work well. My personal preference is the Soudal stuff, but there's very little to choose between any of the low expansion foams.

This is at the heart of the problem, as it all comes down to how quickly heat transfers between the deliberate and incidental heating sources, the room air, and the structure and furnishings. Even if we just take the four materials that have the greatest influence, air, gypsum plasterboard, concrete and water, then looking at their heat capacities and thermal resistance characteristics shows that there is a significant challenge. Listed in order of greatest mass heat capacity: Water = 4181 J.kg-1.K-1 Plasterboard/plaster = 1090 J.kg-1.K-1 Air = 1012 J.kg-1.K-1 Concrete = 880 J.kg-1.K-1 Then listed in order of decreasing thermal conductivity: Concrete = 1.5 W.m/K Water = 0.6 W.m/K Plasterboard/plaster = 0.19 W.m/K Air = 0.025 W.m/K The main problem seems to be that in many cases, the incidental heat transfer medium is air, heated by people, showers running, solar gain heating up surfaces that then heat the air, cooking etc, and air is both a lousy thermal conductor and has a pretty low mass and volumetric heat capacity. Things do look a little different if you look at the volumetric heat capacity of these materials, bearing in mind the fact that there will be a lot of plasterboard virtually in contact with the room air, so it has a potentially large impact on thermal buffering, limited mainly by its relatively poor thermal conductivity, which will tend to slow down the rate at which it absorbs or releases heat: Water =4,179,600 J.m-3.K-1 Plasterboard/plaster = 3,037,830 J.m-3.K-1 Concrete = 2,112,000 J.m-3.K-1 Air = 1210 J.m-3.K-1

Our Local Authority only update the planning website every Friday, so something can be submitted for the website on a Friday afternoon and not make it on to the website until the following Friday. It's not at all uncommon for there to be a backlog of correspondence on planning waiting to be scanned and redacted before going on the website; I think one or two of the responses on ours took around three weeks to reach the website. You can ask to see the whole planning file at any time though, if you wish. There will be stuff in the planning file that won't be on the website, too.

It means that the planning case officer dealing with your application has made a recommendation for either approval or refusal and either passed it to his boss for sign off, or passed a report saying the same the planning committee. As there is no indication at this stage as to which way things are going, have a look and see if you can see an "officers report". If not, call them and ask if you can please see it.

Yes. I've seen no evidence from data logging in our house that there is any appreciable heat transfer from the house to the slab. If there is much heat transfer, then it's both very small and very delayed, such that it doesn't seem obvious from looking at the room temperature and slab temperature data. The only exception to this is if we deliberately cool the slab to around 18 deg C. That does have a noticeable effect on reducing the air temperature fairly quickly (within around an hour or so).

I don't know anything about Future Found. The only system being offered at the time of our build was the Kore system, and that has NSAI approval. Our BCO wanted proof that the system was compliant, so I sent him the Kore report, plus the NSAI chit and all was OK.

The MBC foundation system is by Kore, and is approved to the Irish equivalent of BBA (in effect), NSAI. This is accepted by building control etc as an approved foundation system design.

As another data point, the data logger in our house logs to a resolution on 0.0625 deg C, and generally we find that the ASHP runs at between 3.8 and 4.5 COP, significantly better than the spec. Part of this comes from running it at a relatively low flow temp (40 deg C), part comes from running the UFH flow at around 25 to 26 deg C. The UFH return is rarely more than about a deg or so below the flow, and the ASHP runs for around 1 to 2 hours every couple of days in this cold weather, as long as we are only using it for heating. Room temperature is reasonably steady at between 20.5 and 21.5 deg C, and only seems to change very slowly under most conditions.

There is a very definite impact when visitors arrive, as they heat the air in the house fairly quickly, at around 80 to 100 W per person. Five people is roughly 500 W of pretty high heat transmission rate directly to the room air, and that does raise the air temperature in the house fairly quickly, certainly within 15 to 30 minutes the temperature will have increased by a degree or so. Circulating water in the slab has a longer-term effect of keeping the slab temperature even when the heating is off, and it is effective if there is an area of floor that receives solar gain, in that it will effectively cool that area (by moving the heat elsewhere in the slab) and has a disproportionately significant impact on lowering the air temperature. The latter is mainly because the sun can quickly put enough energy into a small area of floor so as to raise the Δt a fair bit - I once measured a floor surface temperature of nearly 30 deg C by our front door, before we fitted the external IR reflective film. Taking this heat away and distributing it to areas where there is no solar gain reduces the overall floor to air Δt and so decreases room air heating a fair bit, particularly when the time-dependent variables are accounted for (heat capacity, thermal resistance etc). The real challenge is to come up with a way to tame a system where you only have control over a relatively small part of the heat energy input. This is in contrast to a high heating requirement house, where generally incidental and solar gain in late autumn, winter and early spring is small, and the heating requirement is well and truly dominated by the heating system.

No, they are around 30mm from the surface, so not deep in the slab. They are 16mm diameter UFH pipes, tied to the top of 6mm diameter reinforcing fabric that is sat on 50mm chairs. The slab is 100mm thick. Anyway, structural concrete has a typical thermal conductivity of around 1.5 W.m/K, whereas dry air has a typical thermal conductivity of around 0.025 W.m/K and water a thermal conductivity of around 0.6 W.m/K, so heat transfers out through a concrete slab pretty quickly and easily.

Broken down the formula just gives an approximation of the total heat emitted from a heated surface that approximates to a floor with an average emissivity and assumes a typical convection heat transfer factor. It's simplified a lot by the inclusion of fixed factors for emissivity and convection heat transfer, but is good enough for most practical purposes. Don't rely on it for value of Δt outside the range of a UFH system, though, or for emitting surfaces that are not horizontal or of a similar emissivity to a typical floor covering. I did try this, but the time lag is very high, around 10 to 15 hours, whereas solar and incidental gain can give local heating effects within tens of minutes. One of the greatest heat emitters in our new build are two grey stone internal window cills. They can easily reach 35 deg C in winter sun, and are large enough to contribute a significant amount of heat once the sun has warmed them up. The same used to be the case for the cream travertine in the hall, but fitting long wavelength IR external reflective film on the hall glazing has reduced that a very great deal.

Read back on my efforts, they may prove interesting. I started from the premise that with a low heating demand and UFH in the slab, controlling the slab temperature should be quite good enough to control the room temperature. Over the very small range of floor surface temperatures required, to give zero to around 15 to 20 W/m² heat output with a nominal room temperature of around 21 deg C, then the floor surface temperature variation can be considered to be near enough linear, making the maths and controls a bit simpler. The theory goes like this. If the slab is kept at the correct surface temperature for the prevailing heat loss (determined roughly by the inside/outside temperature differential) then the system should self-regulate. If the room temperature drops, say because an outside door is opened, then the temperature differential between the slab surface and the room air increases, so the heat output increases. As the room warms up the temperature differential decreases and the heat output decreases, until equilibrium is reached once more, where the heat input exactly matches the heat loss. Sadly this doesn't happen in the real world. I tried many variations of the control system to try and get floor slab temperature control to work, with dozens of firmware variations and three different sets of control hardware. None worked well, and in the end I tried a simple, but very low hysteresis (0.1 deg C), room stat and was surprised to find that, as long as the flow temperature to the UFH is kept below about 25 to 26 deg C, this works very well indeed. I have looked back at why the theory wasn't supported by the real world experience and reached a view as to what I believe to be the main problem, and that is that the incidental heat gains to the house often swamp the heating system heat output. Unless the control system knows what these incidental gains are, it cannot maintain an even house temperature. In our case we had significant unwanted solar gain, almost entirely in late autumn and early spring, when the low sun angle got under the external shading and penetrated deeply into the house. I worked out that we could easily get over 1 kW of solar gain on a bright, cold, clear wintry day, and that was more heat than the whole house needed. There were other really big incidental heat gains too. Run a shower for ten minutes and you dump around 2 kWh of heat, of which a fair proportion heats up the air and gets recovered via the MVHR. One very significant factor when I was working inside the house was the vacuum cleaner. I have an ancient Vax that puts out around 1 kW of heat when it's running. Half an hour of cleaning up around the place on a cold day would easily increase the room temperature a couple of deg C or more.

The term "cess pit" is being used here, when I'm nearly 100% certain that there cannot be a cess pit. Worth clarifying, as a cess pit needs emptying every 2 to 3 months, as it's just a storage tank. They are pretty rare now, mainly because they are costly to maintain and because modern water usage rates mean they need emptying far more frequently was the case when they were initially used, tens of decades ago. I think it's far more likely that what was being used was a septic tank, a completely different system altogether, and one that allows the effluent to settle, the sludge to anaerobically decompose and the liquid effluent to drain to a leach field where it is supposedly treated by aerobic soil bacteria. A septic tank only needs emptying when the sludge level builds up, perhaps every one or two years or so.

I think @Ian has nailed it, the water company are quoting the public side rules, not those on the private side. Our foul drain crossed over a water supply pipe in the lane for example, and is only 350mm away from it, as there was no other solution, Similarly, further up the lane the water main and foul drain run side by side in the same trench. They are over 750mm deep and separated, one one side of the trench, the other the other side of the trench, but that's all. The 3m easement is an access rule I believe, it just means that on a public pipe they need a 3m wide strip available above the pipes in order to access them when required (basically it's the width needed to get a digger over the pipe, with room to manoeuvre).

Perhaps we're guilty of taking a too US-centric stance on this. Certainly the US dominates the internet, but many of the really big servers are in Europe, and AFAICS, UK and EU legislation isn't likely to change to allow ISPs to favour one particular content provider over another. That really leaves the big potential knock-on effect of things like search engines, the vast majority of which are all still US based, and so, unless they deliberately change their search algorithms to compensate, will serve more results for the bigger bandwidth users, I suspect. Google has, in my view, become near-unusable already if you are looking for unbiased technical information, as even with quite specific and complex Boolean search strings it still serves up several pages of paid for crap that has little relevance to the search. At the other extreme, engines like DuckDuckGo use a shotgun approach, and serve up loads of irrelevant answers just because their search algorithms are crap. I've been playing around with search engines a fair bit recently, driven by the exceedingly poor performance of the big players (unless you are content to be product placements instead of proper search results). The golden rule seems to be to always search via a VPN and always via a browser set to accept no cookies at all. It helps if you search from a smaller window, too, as that restricts the chance of bias from browser profiling. Sadly, one of the better ways of finding stuff quickly and accurately seems to be to use the Tor Browser, via a VPN, and search using the Dark Net, as the chance are that you will find the information you want far more quickly. It'll be interesting to see how the change in this US legislation impacts the rest of the world. My guess is that there may be a backlash, with more server farms relocating out of the US to countries where there is still freedom for every website to carry a "weighting" based solely on it's popularity, rather than how much it's owners pay an ISP.

I think the main issue is the side effect this will have on all of those that don't use any of the big services. I can see that the big search engines will quickly become even more challenging to use, in terms of getting balanced results, than they are now, if the big players are the only ones with lots of bandwidth. My main concern is that those that use the internet for non-commercial purposes, like this forum, will be sidelined and lose bandwidth to the point where they are even harder to use in some areas. My broadband speed is already slow, and it looks as if it will now get a great deal slower if my ISP agrees to allocate more bandwidth to streaming services that pay them to slug down everyone else's connection speed. That would be a real PITA, but thankfully we do still have some smaller ISPs who may not choose this path, like Andrews and Arnold, so perhaps the thing to do is switch away from the mainstream ISPs if your don't want your internet speed to be throttled right back by the activities of Amazon etc in streaming video.

I've designed a few liquid/gas eductors and have the formulae to hand somewhere if you need them. Air to air eductors are a bit more hassle, because the density of both the motive and suction fluid is the same (unless you do a Dyson and accept the noise of accelerating the motive stream beyond the incompressibility limit - not a good idea in my view, for this application).

Ye, it would, but they are specifically designed to be operated at a contant current (with the occassional over-current cleaning burst) and to measure mass air flow, not temperature. All the ones I've seen use a bead thermistor in the air chamber to compensate the hot wire for air temperature changes, so that the sensors reads mass flow rate reasonably accurately.

@PeterStarck, it looks as if there may be a fibre washer under that anode, so it could be something as simple as just removing the anode, checking the fibre washer and refitting it after a bit of a clean. It may even be that the anode just needs to be tightened slightly, say 1/4 of a turn, to seal on to the washer properly. Failing that, removing it, wrapping PTFE tape around it and refitting it would almost certainly fix it.

It's hard to beat these small (1.8mm diameter) glass bead thermistors for a fast response over the sort of air temperature ranges of interest: http://www.farnell.com/datasheets/2137899.pdf The only problem is that they need to be compensated for non-linearity and offset, but they respond to temperature changes very quickly. Somewhere I have a stash of even smaller ones, around 0.5mm diameter, that were used in pairs in a half bridge inside a bottle variometer sensor in a glider. They are even more sensitive to tiny changes, but they are a pig to handle, with hair fine wires,