MikeGrahamT21

Hi, We have 2 windows which face south, and cause the majority of the overheating in those two rooms during the summer months, so I'm wanting to put a brise soleil above each window, but I'm guessing the manufactured aluminium ones will cost lots of £££, so I'm thinking to make a couple from timber and paint it 7016 grey to match our window frames. Does anyone have any ideas on design for the blades? Any one else embarked on such a project? Regards Mike

I have just completed an extension in a very similar manner, vaulted ceiling with 225mm insulation (we did full fill with PIR, and then had to counter batten the roof for the 25mm air gap), and we have 2 roof windows on the south facing side which work quite well. We used Okpol roof windows, however the air tightness wasn't what we were led to believe, and I think in general airtightness in roof lights is probably an issue, so thats one thing to consider. Our U Value on the roof was around 0.11 in the end, the roof windows even though they are triple glazed is 1.0U, so a lot worse, but you have the solar gain in the day time when its sunny. We have both older double glazed in another roof, and these newer triple, and the triple are a LOT quieter when it rains, you could certainly sleep with it, but you can still hear it. This particular room has a lot of glazing elements, 2x2.1m bi fold doors, and a massive window at 1.6mx1.9m all triple glazed, and the room even when we have had -5c a few weeks back required around 10minutes of heating first thing in the morning and that was it for the whole day. Now with this warmer weather, the heating hasn't been on for days, holding a nice 21C. So for us, there is no negative impact in terms of efficiency. One final thing to note is overheating in the summer months, this year we have decided to add on Awnings, which are external blinds that cut down heat ingress by what they say is around 80%, so we will see how they perform.

How about these: https://www.creative-cables.co.uk/metal-ceiling-roses/7053-black-cylinder-rosette-kit-bracket-screws-and-cable-retainer-8057730181235.html

According to U-wert Phenolic Set insulation (Kingspan Kooltherm) also has a very good heat storage capacity, not quite as good as wood fibre, which seems a bit odd for a foam product, but it is extremely dense compared with PIR, will get nearly a 10hr decrement delay, which isn't too bad, plus its the most insulating of materials, unless its an error on their calculator. I find buying from seconds and co is a good deal cheaper than new, the boards i received were barely marked, but they were effectively K5 EWI boards, so fibre lining on both sides, instead of foil, but that was fine for what i wanted them for. As far as a ceiling is concerned, decrement delay definitely needs to be considered, it is very important in terms of comfort in the summer, but also balancing temperature in the winter.

So a while back I decided to send an email to British Gas FIT team to ask about the re-positioning of the panels, thinking they would come back saying no, to my amazement they rung yesterday and said as long as the panels aren't changing size or power output, and the system still goes through the same single MPAN, then we can re-position, and they sent it me on an email in writing. So good news on a few parts, this means we can go with the 6 panels south, and 2 extra east, and more importantly, we have the west side roof now free for a dormer extension!!

I used these screws on everything from the roof trusses to the floorboards, fantastic quality and very cheap, and they are rated as structural screws hence the use for roofing: https://www.toolstation.com/forgefast-multi-purpose-self-drilling-wood-screw-tub/p91716

British Gypsum make a product called GypFloor Silent: https://www.british-gypsum.com/white-book-system-selector/systems-overview/floors-and-ceilings/gypfloor-silent This goes underneath your chipboard and should do the trick. I would imagine its fairly expensive though. Are you sure you need sound proofing if its just a storage space?

Absolutely, but the systems shown above, even though they are south facing, are performing twice as good as ours in some cases. The PVGIS would be about right i'd say, we did 125kwh last February with a 4kwp system. The yellow bar person got nearly 200kwh last feb, so that also fits the bill. Just seemed a bit shocking yesterday just how much difference there was. Ah well, at least we are in the right bracket for performance, i'll stop worrying about it now and move onto something else lol

So after messing around with the optitrac parameters, I can see we get a tiny bit less on a morning, though generation begins earlier, but the afternoon is much better, and longer, with middle of the day roughly the same as before, overall, we are generating more now than ever before. I've compared our solar array with others in the area (as local as were published on sunny places), and found that we trail behind massively. Looking on google maps, the yellow line is almost perfect south facing, and the red is pretty much south, slightly west, where as we are east west split, so I can agree there will be a difference, but this much?!?! We are of course in green:

I dont think it works at all in terms of ROI at present. Power cuts would be a big benefit, and then the only other thing is the warm fuzzy feeling you get from self consumption, but I guess all you are doing is paying for the electricity up front. We would still need a grid connection, and maybe only achieve a 75% overall reduction, so 25% from grid plus the standing charge, but it would somewhat protect from price rises. I'm waiting to see what contract i end up on in October, see how much its gone up, as at the moment we are on 11p/kwh which is pretty cheap really. It all depends how much prices rise, anything above 19p/kwh for us would land a profit over the 10 years.

more than likely, as i say in first three years they say its fixed at £50 a year, thereafter its a percentage (50% i think) of the profits they make out of doing it, so I suspect its very low. Trade off is unlimited warranty. Just wondered what peoples take was on this as its a little different to some of the other offerings. There is one I got recommended a while ago which is the LUX AC storage with Pylontech batteries, around £3400 for 4.8kwh all in, self install, and this also has the gridshare incentive option available, but doesn't give any extra warranty, just the standard 10 years. I wonder if people will start selling extended warranties for the batteries. Or maybe it would be very unlucky to have one break??

I agree, it is very expensive. According to the blurb, the warranty lasts as long as you are a member of grid share, so potentially forever. Obviously grid share can drain your battery too for others benefit, which could be seen as a negative.

Came across this a while ago in the Grand Designs Magazine, a UK designed battery storage system, currently they only sell 2 and 3kwh systems, with the 3kwh being about £3900 fully installed, and they're launching a 4.8kwh soon, which is the capacity i was thinking would be about right, though I dread to think how much that would be, maybe £5 or £6k? Normally, these would be a big no no in terms of return on investment for the usual 10 year warranty, however these units firstly support the grid share incentive, which gives £50 per year for 3 years, then a percentage (which would likely be next to nothing), and more importantly if you sign up to grid share, they will give you an lifetime warranty for the battery, which somewhat changes things a little? The only thing is, what they class as 'lifetime' and that i'm not sure about. What do you think, worth it or not? Or would it be better going for a much cheaper system with the same capacity, as you can get this capacity for around £3k now, with self install. I asked for a quote a while back, and they do pester quite a lot, which is a bit of a put off.

Fair enough, that sounds like a good enough reason to drop EWI. Thermal Mass, is probably better called Heat Storage Capacity, its is a materials capacity in which to store heat, and release it slowly to the environment, which in theory dampens the temperature from moving so much either up or down. A room with IWI will warm up very quickly, a really fast response, because the insulation prevents the heat from having to warm the heavy masonry behind it, but in contrast the heat will dissipate quicker than it would had the walls stored some of that heat. This room would have a low heat storage capacity. One with EWI allows the walls of the building to store the heat, with the EWI acting like a tea cosy, keeping the heat in the walls where you want it, so the room would take a long time to warm up initially, as you are warming not just the air, but also the masonry, however once warmed, it should keep a reasonably constant temperature with little heat input. This room would have a high heat storage capacity. EWI should also help on a sunny hot day in summer, as the walls will be relatively cool, so any excess heat gets absorbed by the walls, keeping the temperature down, whereas in the room with IWI you would potentially get overheating unless you put measures in place to reduce this potential. A free service such as this may help you simulate your plans, and understand thermal mass/heat storage capacity: https://www.ubakus.de/u-wert-rechner/? This also models the Phase Shift, and temperature amplitude damping which i spoke about above, which are quite important. Site is in german, so use chrome to convert it. Hope it helps.

Is there a particular reason for not wanting external wall insulation? You stand to lose an awful lot of thermal mass capacity which you may regret in the coming hotter years.

Having had a room done with dot and dab on celcon blocks, I can only recommend not doing it!! If I knew what I know now, it would be wet plastered, yes its more work for the plasterer and will cost more and leave a bit more mess, but its worth it in the long run. I now have infront of me much drilling and many cans of expanding foam to try and salvage it, as heat loss is immense, despite having enough insulation to achieve around 0.18U

British Gypsum Easifill - its a jointing compound which has been spoken off, very easy to get a smooth finish and sands well, but be prepared for a LOT of dust

Looks like they use the decentralised systems that blauberg do. I've not found anything negative about their systems, was hoping there would be some reviews on Amazon as they sell on there, but nothing so far. The only downside I can see is their units don't do automatic summer bypass, its a manual process, thats the only negative i've come across so far. Now I have a spec, i can look into other units, originally the one i was going to get was the Brookvent aircycle 1.2, which seems to have all the features we want, so I may have to go hybrid and pick the best components from each supplier.

Had a kit list from them now, and more importantly they did a design and airflow design for the project, free of charge, which i've been after for a long time! Their units are SAP Q listed, which appears to be one of the most important things to have, but would like some real life experience to back it all up.

So this has been the first day with full sunshine from morning til night, Ive kept the global optitrac switched off since Monday. Looking at the chart we lose a little first thing and last thing, but everything in between is better. Last time we had nearly as good generation was Jan 2017, but the temperature was higher that day, we did 5.0kwh, today just done a 5.12kwh which is the highest january amount we've ever recorded. So I don't think we are going to see huge increases, but for us this value should have always been set to off, and even with 2 more years under their belts the panels have put out more today than they've ever done in the month of january. I've also noted the power curve is different with optitrac turned off, its smoother. This is todays with it off. You can also see the drop off morning and night. This is before I switched it off, the curve is a lot less smooth, but doesn't drop off quite as sharp first and last thing. Ultimately, its a shame optitrac can't be scheduled to switch on at certain times of the day, as first and last thing would gain us a tiny bit more, but overall, i think off is best for us, and i'll continue to monitor as the months progress. It is almost impossible to directly compare, since no 2 days are the same

Yeah I can't figure out what Current 1 and A are, as they are almost the same, just slightly different, unless its Current (DC) and Current (AC) i.e. showing the inverter losses. I've disabled the Optitrac Global Peak functionality, as we have absolutely no shading what-so-ever, and according to internet sources this can reduce performance by as much as 2%, might not sound like much but thats around 70kwh over the year, which is a lot when its a simple setting. Still not had a reply back from SMA yet about SD card type, though I suspect its 1st gen SD, once I get one of those i'll do the firmware upgrade on the unit and see whats better about it, wish they would include release notes, they used to do

This was when the sun came out at 11.30 today:

Hi, I'm doing a bit of forward thinking for when the bathroom eventually gets ripped out again, previously i only replaced the rotten timbers which was the most important thing at the time. Currently have an underground connection (rather than through wall) for the 110mm soil, with it being a 60's house this is a clay pipe, which current has a 110mm flexible soil pipe shoved into it, and then this has another one of the same flexible connectors in to bring it to floor level. Obviously the flexy connectors have many ridges in them, which just seems a really bad thing for flow and the potential of blockages. Going out of the wall and capping off the underground would be the easy option for sure, but it would lead to more potential of air leakage, and thermal bridging, so the underground is preferable. I'm thinking to get a clay to plastic connector, and use some solid 110mm pipe as far as I can, ideally this would be up to floor level, but this may not be possible as if I remember right, there is a joist just where the toilet soil pipe lands, so there is yet another flexible connector into the other two flexible connectors to get around this issue!! Any ideas? Mike

Since I darent move them, I’ve nothing to lose asking British gas for special permission and see what they say, at least that way we can’t be in the wrong. will monitor pv next week and get those figures which were asked for

Oddly the guy who came was from E.On and we are with British Gas for the FIT payments, so no idea how that works. You're right, there is no data regarding orientation on the sheet, but the company i contacted said straight away, you can't do it, and i can't see why they wouldn't have wanted to, as its free money for them.