gravelld

Does the party wall open into the loft? You could take some bricks out and fill it, although I'm not sure on the legal ramifications.

For context: the EPS vs XPS below ground battle had been going on for some time. Most specifiers state XPS because in theory it shouldn't absorb water. Others say in practice it does, over time, and EPS dries out better. I'd be very wary of using PIR in this situation. Once it goes, it goes, and you'll have a lot of soggy ineffective insulation.

Most firms use just foam or mastic because that's what installers are used to. But you're best off with tape long term. Make sure the installers have experience or have someone to teach them on site.

Most alu clad have a drainage channel behind the alu. Internorm don't; they fill it with insulation. So, product dependant, it's a straw man to say alu clad have a problem with water penetration. Check the product.

Its not just that assessors won't fill in the correct data... In some cases they simply can't. My assessor did update the assumed values when i showed him the insulation, but the possible values only go up to a certain level. He had no way to enter Uw values for my 3G - he just had to check the 'double glazing' box.

Ok, maybe I was incorrect in assuming your issues with the system were derived from under specifying the active heat input from this system. I'll bow out.

So, feel free to yell at me to review a post I missed but... If this was incorrectly specified in the first place, why aren't the installers removing and replacing with a more appropriate solution under the MCS guarantees? I thought MCS would guarantee an accurate heat loss calculation and product choice, and cover the customer if these things weren't done correctly? I partly ask because I'm going down this road myself and I would like to be informed...

By the way, my own PHPP model comes out at 10kW maximum heating load down to -2C. It also has a lower overall heat demand, I guess because the proper U values of the windows and the actual air permeability is taken into account.

I'm guessing this is the RHI rearing its cost externalising head again. i.e. the installation is overcharged to a non-trivial amount, and the tax payer picks up the bill. I guess?

I thought it would be on for more than that - that's the recommendation for a heat pump, no? By these calculations, the 12kW (you meant kW right?) pump would be ok if on for 16 hours... but that's the coldest day so I'm less worried (plus we have a 12kW wood burner to top up - although I don't want to depend on that). Is there a reason you said 12 hours per day? Not sure about the rads - the quote says "Radiator upgrades included if required". Is there a way of deriving a desired m2 of radiator given the heat pump size or heat demand?

After a recent disaster with our oil tank, I'm checking the feasibility of getting an ASHP installed. A local installer with a good reputation have appointed someone to do the heat loss calcs. These came back and are as follows: Energy required to heat property 26,570 kWh Energy required for hot water 4,588 kWh Suggested ASHP Vaillant aroTHERM Plus 10kW VWL 105/6 A230V S2 Size of Hot Water Cylinder 250 ltr Our current energy use for space heating and DHW combined is less than 18,000kWh - I know this because our oil tank is 1800L. I guess the discrepancy is because we don't heat the whole house to 21C or whatever the MCS survey requires. Also, air tightness wasn't considered in the assessment, which I've worked hard to get down and has been measured at 5.8m3/hm2. And neither is our 3G ("double glazed"). I have suggested oversizing to the 12kW model as it only costs a few hundred more and it should give us some breathing space (and better efficiency?). AIUI the efficiency is related to the flow temperatures. How do I ensure the specifiers have not underspecced and we can still achieve a high efficiency? The specs for this range of heat pumps are here: https://www.vaillant.co.uk/for-installers/products/arotherm-plus-71424.html#downloads I expected more like a 300L HWC to be specified. We have three bathrooms with showers, four residents, but also occasional visitors. If anyone could take their valuable time to run their eyes over that and flag up anything worrying or missing I'd be grateful.

I was wondering the other day how much cumulative energy is lost through all the downlighters over the country that vent into an unheated loft space. Their popularity since the early 00s must mean there are a lot of these, and I rarely see them properly sealed. I remember when I fixed my loft - first job was clearing it out, then before re-insulating, it needed massive air tightness treatment. We had around twenty downlighters just venting into the loft - put your hand over them when it was cold in the loft and you really felt it. On the other hand, if the wind is blowing the right (or wrong, depending on your perspective) way you can feel the down draught being forced into the building. Did the old clay plant pot trick (and changed to LEDs of course) and I think that was the single biggest intervention I've made on air tightness!

Wow - if they manage to get that through without watering it down... I can't for a moment think this will become law.

They are now, this tank was installed in 1999.

Yesterday: disaster. A whiff of oil when standing on our driveway. A crack in our oil tank (plastic, 22 years old)! Fortunately it was very small and I patched it with a bar of soap and a bit of Tescon Vana ? We have now decanted to an emergency tank. But the new tank is going to be more than £1k so I'm beginning to think about moving onto an ASHP. Also, it looks like the Clean Heat Grant is going to be less generous to larger installations. So I'm thinking we might want to get moving. Does anyone have any recommendations of a heat pump installer covering the East Midlands - Leicestershire specifically?

It's the latter I've used although only as a weather seal, not the air tightness aspect.

There's also Iso Chemie Monobloc to consider...

I have a circulation pump on my DHW return which I use in five or 10 minute spells just to circulate the water so that we can heat the entire HWC from solar PV via the top-ish mounted immersion coil. Otherwise, only the top third or so gets heated before the thermostat kicks in. The pump is installed on the return to the HWC. Vertically, it is in the loft, roughly in line with the bottom of the cold water supply tank which feeds the HWC. The HWC is in the bathroom below. After running through the pump, the water goes back downstairs into the bathroom and into the bottom of the HWC. Before the water hits the pump, the feed from the HWC goes into the loft, across the loft, down into the first floor to service three bathrooms, then down into the ground floor to service a kitchen. Then it returns to the above mentioned pump. I end up having to bleed air from it every few weeks. I know when I need to do it because it begins to make this squeaky sound: output_20210327_144531_half-transcoded.mp4 I bleed the air from it for a few seconds (actually, sometimes I stop and start the pump to try to eek out as much air as possible), and it works again. How do I avoid having to do this so often? It's a bit of a pain to have to go into the loft so often. Now though there's another problem. The pump sounds like it's stuck. It just makes a mid-pitch buzzing noise and the pump doesn't turn on. I couldn't capture this in a video, for some reason. It did this once before and I gave it a tap with a light hammer on the bleed valve. That's not working now. Is it clogged up, and if so is it repairable?

Thanks everyone. I got the kit from Ultra LEDs and everything wired in really easy.

Yep, get it now. Thanks everyone.

It's just that the strips I've seen all connect to the driver with a different connector. I'll have another look.

Thanks. But those drivers have outputs for two-core flex don't they? LED strips have a different type of connector. Do I simply cut the strips to length and attach a plug that is compatible with the driver, e.g. https://www.ultraleds.co.uk/easy-to-use-snap-connector-and-cable-3a-1500mm-compatible-with-syndeo ? Seems like it's all proprietary sockets, am I missing something?

I'm trying to source some LED strip lights like https://www.ledspace.co.uk/collections/12v-white-led-strips . However, I want them to run off the dimmer switch on the wall - i.e. be on the lighting circuit. Is this possible? I noticed this on LED Space website: Does that mean I have to source a mains voltage strip and is that even possible?

Something called SecoFLEX. As I didn't use anything else I can't really compare it to anything else, but in general it's stood in good nick for the past year and a half. No cracking yet. The contractors removed the bad bits, replastered and then recoated. If you're going to the trouble of scaffolding and removing the existing, maybe consider EWI with a silicone render.

Don't forget to air-tighten under that dot and dab...