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Crap!!! The flat roof is too high (which is why the ridge tiles are higher), I have seen the flat roof be extended over the front roof and ridge tiles not used (looks rubbish IMO). The ridge has been raised so Technically it needs planning permission (but doubt the council will notice 🤷‍♂️).

I am not understanding why a flat roof required them to alter the ridge of the peaked roof? I am not even sure from the pictures where the flat roof referred to is? The ridge tiles are appalling, they should all be the same size and I think the apprentice's son must have bedded them in, a very poor job indeed.

See my Fred and Joe example. I note they also round the answer to two decimal places one is 0.175 the other 0.170 Too late at night for me to spot any errors 🙂

Using their R Layer values.. 1. Surface effect/Rsi 0.130 2. Plasterboard 0.06 3. 10mm cavity due to dot and dab approx 0.13 4. 100mm blocks 0.085 or 0.204 5. 10mm cavity due to dot and dab approx 0.13 6. Plasterboard 0.06 7. Surface effect /Rsi 0.130 Total R value 0.725 or 0.844 depending on the block. U-values would be.. 1/0.725 = 1.38 or 1/0.844 = 1.18

It may be useful when doing a room by room heat loss calculation for sizing heating/cooling systems. k = W.m-1.K-1 [thermal conductivity] R = L / W.m-1.K-1 where L is thickness [thermal resistance] U = 1 / R = W.m-2.K-1 [thermal transmittance]

For a sandwich of materials you add up the R value... R = R1 + R2 + R3 Or the reciprocal of the U values.. 1/U = 1/U1 + 1/U2 + 1/U3 or.. U = 1 / {1/U1 + 1/U2 + 1/U3}

In a nutshell, yes, so minimising the capital cost is of paramount importance if you want to even glance at breakeven / RoI numbers Folk need to remember that charging off excess and then using it of an evening is a relatively easy life for a battery system. Change the scenario to where you sign up for the Tesla / Octopus arrangement and your batter is in for a kicking, thus further reducing its useful lifespan ( can drop to 7 years of 'usefulness' vs 10 with the right amount of abuse. I'd be interested to hear what the warranty wording is like for that system in that arrangement, as they benefit from beating the shite out of the system you paid for.........and then own.........and have to maintain / repair / replace....... @Wil I'm waiting to get a reply from a supplier for an Iconica hybrid inverter ( 11kW ) which is sub £1500, and then I can open my horizons to which battery I choose to employ ( within the manufacturers recommended connectable equipment options of course ) but I am also looking at BMS options to charge near end-of-life commercial vehicle batteries. Cheap option, with fleas that come with the dog ( monitoring / replacement etc ) but the costs should be vastly cheaper. All depends if you want a nice looking shiny box that someone fits for you, or if you want to ( and are able to ) get your hands dirty with a bit more of a bespoke setup. Pointless doing anything unless its really worth doing tbh. Change of £9k before VAT........ https://www.photonicuniverse.com/en/catalog/full/566-20kW-Zero-Transfer-Uninterrupted-Power-Supply-UPS-System-with-48kWh-energy-storage.html

I was quoted £14.5k+VAT in Janurary, but this went up to £18.5k+VAT in June (including gateway and install). You can use them in a power-cut. You need DNO approval. PW's won't export to the grid, only cover loads. (although in 3-phase setup, using the gatway, it will export on one phase to compensate for load on other phases).

Sorry but no. It says the thermal conductivity is 1.17W/mK (eg not W/m^2k). Thermal Conductivity is the U value for a notional 1m thick wall. So 100mm thick wall would have a u-value 10 times worse at 11.7W/m^2k. That's consistent with the R-value quoted for 100mm blocks of 0.09m^2k/W.... U=1/R = 1/0.09 = 11.1W/m^2k. For the insulite the U value of 100mm wall would be 4.9W/m^2k.

I was the OP on this thread, and can confirm I went with Powerlon UV120. The manufacturer confirmed they were happy with two layers of breather. Just to be clear, my setup is: - TF house - Thermo TF200 - battens - counters - Powerlon UV120 - vertical cladding We are doing an insect mesh to the bottom, and top for extra ventilation.

https://www.ebay.co.uk/itm/333714806299 can't get much better than this stuff. £8.75 a can from this seller on eBay is where I got mine.

He's just saying that. 9 year old people called Joe are your greatest fans.

Christ on a bike. If you have not paid them yet, then DON'T It looks to me like you are having a loft conversion done with a flat roofed dormer. They have run into trouble with headroom so jacked the dormer roof up to the point it is too high. then the laid the ridge tiles back, cementing them onto roofing felt, and cocked up at a funny angle so they are higher than the end ones set correctly (but badly) I suspect your builders turned up on horseback, wearing spurs and big brimmed hats? I don't know how to correct this mess, but mess it is and I would not want it left like that.

Good question. It retrofit circles airtightness is claimed to be the first low cost biggest bang for buck improvement followed by insulation. On new build, BRE suggests airtightness accounts for about 10% heat loss. I've seen other figures suggesting 15-20%. Energy Saving trust puts a figure of 30% losses down to thermal bridging. However, countries like Sweden put airthightness at the top of the list in terms of importance for energy efficiency - it's first design for airtightness then insulate. I don't think the overall heat loss is 'just' down to the heat capacity of the air but how that movement of air impacts thermal loss of all elements - we know how much eliminating convective currents within insulation layers improves energy efficiency for example. Like with everything, it's got to be a balance of what is done to what extent and for what cost?

@SteamyTea Not an answer to your exact question - I use a cheap sonoff to switch a contactor on my storage heater - all "off the shelf", in a little 2 way DIN rail enclosure. Marginally more expensive. Could be used for an immersion also. 6A MCB provides 240v feed to the sonoff. (reflashed with ESPhome for home assistant integration but could be left as is to use the sonoff app. Shelly etc would also work)

If the volume of air in a building has a mass of 1 tonne, is changed 5 times an hour (typical ACH for a new build) and the temperature difference is 12K. Then that is 150 kWh a year. Don't sound much, but old houses leak at a greater rate and the delta T is for my house in mild Cornwall. My small house has a volume of 160 m³, so a mass of 200 kg. So 30 kWh/year. 6 quids worth of E7 electrons. Still going to improve it though.

Responding to an earlier question around Solics, I have the solic diverter which is great, but overheats in the electrical cupboard and self-limits the amount it puts into the immersion resulting in occasionally not diverting as much as it could. I need to find a way to move it to somewhere where it doesn’t overheat. Otherwise it’s been excellent and has paid for itself in around 2 years. I also have a Shelly 1PM in parallel (previously a simple timer) so that I can boost the DHW or run it for a couple of hours at E7 to make sure the DHW is in place for the morning. Seemed like the easiest way of diverting but retaining the ability to boost/ timed DHW without pressing the green button on the front of the Solic.

Insulation is often retrofitable. Airtightness, not so much. My understanding here, which may be wrong, is that when we're talking about airtightness we're not really talking about drafts which are relatively easy to prevent. But of all the things that sap energy (that's costly to replace) air change is thankfully the least in significance due to it's relatively low specific heat capacity. Heating a given volume of air by a given amount requires a lot less energy than the equivalent amount of some other medium such as masonry. I said "thankfully" above because, in my opinion, airtightness is probably the most difficult thing to achieve and can only really be achieved during a new build or complete renovation. And even then, it's not something you can employ a non-specialist to do for you so often becomes the preserve of the fully hands-on self builder. So is it worth chasing airtightness beyond the easily accessible stuff like gaps around doors, windows and wall junctions?

Kelvin x angular frequency x hour

Perhaps also.. https://community.ui.com/questions/SOLVED-Ring-Doorbell-Connectivity-Issues-to-Unifi/ea902167-d95b-4ac7-b2e3-48baf6498602 If I've understood correctly the solution is to set up the nearest AP/Router to create a network SSID just for the doorbell. If the SSID doesn't exist on other AP that should force it to connet to the nearest one.

Skylights. Sorry I was joking about white PV panels.

You probably want to speak to a supplier, ideally one that will do the design for you, rather than the manufacturers. e.g.https://www.bpcventilation.com/free-estimate The Zehnder Q600 is one of the largest available which claims to support properties up to 350m2 so seems worth a look.

Ooh I do like a bit of scrap and skip diving! Rolling draw for steel offcuts: Sheet metal folder: Pallet buster: Tote from a cut down oil can: Pipe de-coiler: Solar thermal panel: Then there's the unfinished ones... Mini scissor lift: Electric wacker plate: Rotary converter:

No we just ignored you 😎

Frisky devil