MikeGrahamT21

Yeah, i'll be doing it by myself. B&Q sell shorter boards (cerca 1600x634, instead of the usual 2400), which means i'll be able to fit them in the car and avoid delivery costs). Not too bothered about cost difference between the boards, I just want the best product. Always a bit dubious of chipboard and any potential water on them weakening them, hence why OSB3 is my first choice, plus its also classed as a load bearing product which chipboard isn't. Joist spacing is a little over 500mm, so we can't go for any less than 18mm OSB or 22mm chipboard. I'll aim for the OSB i think! And get some D4 glue from toolstation next time i'm down there.

For clarification, the 18mm OSB3 provides as much strength as 22mm chipboard too. Would you prefer chipboard over OSB?

How do you normally install your floor boards, do you cut to the joist, or ignore the joists and rely on the tongue and groove? I've always cut to the joist in the past, but i've heard people doing it the other way too, and relying on the T&G for the joint. Obviously the latter will result in better joints and less waste, but is it strong enough? We are considering 18mm OSB3 TGV4, or 22mm Chipboard TGV4.

OK, looking at those diagrams, i'd say all of the ones i've looked at so far are counterflow.

OK, will keep an eye out for a counter flow unit.

So they quoted 89% efficiency i think for this unit, how can it only be 60-65? I'll keep on the lookout for counterflow, makes sense air at 90 degree angles to each other would pass more heat. All good information this!

I think the end goal would be to use the 75mm Radial ducting for ease of installation, but thanks for letting me know up front. I think my first goal if I can get a reasonably cheap but good MVHR unit second hand, will be to mount in the loft, and give it external air, and then basically just see what comes out of the inlet, if it smells of smoke I can investigate further then, before I go cutting a load of holes in the ceilings and walls.

Thats good to know, thanks for the explanation

Of course it is! My brain clearly isn't in gear today. Would a PS heat exchange need replacing every 6 years?

Actually that particular one i looked at says: Heat Exchanger – Crossed Counter-Flow type, made of PS (Polystyrene). How can a heat exchanger be made of insulation material?

OK cheers for that, wasn't aware there were different types of core. Assuming they were all aluminium. Not really seen much in the way in the specs either what type of heat exchanger they are, will have to keep a keen eye. Would aluminium core last forever bar a bit of cleaning?

Yeah i guess someone has to buy it to make it start. I wish i had that kind of money! lol

I've seen a second hand MVHR unit on ebay, Vortice HR200, 8 years old, but reading the manual the heat exchanger should be changed every 6 years, even if the filters have been looked after. Is this normal practice? I would have thought the heat exchanger would last a lifetime, and perhaps just need the odd bit of cleaning? What im wanting to do, and i think its the only way i'm going to come to an answer, is to mount an MVHR unit where its going to go, feed it a supply and extract, but don't do any ducting to the rooms, and see what i can smell come the winter time in the loft (which has never smelt of smoke), if its smells OK then its not likely to be an issue. Before I saw this one, i'd considered a Brookvent Aircycle 1.2, with summer bypass, which can be had for around £700, which didn't seem too bad, but what do you think about the above unit for £250, and just needs new filters apparantly?

What i want to know is, why do people do it for 'non-financial reasons', I suppose knowing that you doing something positive is good, but if its going to cost you money whats the point? Surely in 10 years time everyone will be wondering what on earth to do with all this battery waste.

We have negative pressure currently and don’t have any issues with the smoke coming in, at present there are huge gaps around the floors, soon to be gone tho. maybe it just isn’t as much of an issue as I’m thinking. didnt think about building regs for the supply as well as extract. it may just have to be a suck it and see project, keep my eye out on eBay for leftover/second hand components and just give it a go and see what happens

Following on from my thoughts about smoke in area in winter, and MVHR possibly being unviable, I’ve had another think. Obviously putting this in we would do away with normal extractor fan in bathroom. Our house will never be truly airtight being a renovation that I’m doing in bits, but hoping to get it pretty decent. as well as summer bypass mode, does anyone know of an MVHR unit which does summer bypass, full hr and extract only, which I appreciate won’t recover heat but will still do the all important extraction in the wet rooms. Just gives us more flexibility in the system. The whole smoke thing may not even be an issue, but at least we have options either way, don’t want to spend a couple grand to realise we can’t use it at all for a big portion of the year. the summer months make me think more about MVHR for it’s cooling ability, and I think that alone would be worth it’s weight in gold, but we must be able to extract as a minimum all year round

Coursing blocks can be useful for lintel heights, to be honest though I just cut mine and everything was OK, just have to cut really straight, the coursing blocks will be more expensive to buy also

Remember with Thin Joint, its the special blocks which are slightly larger, and made in a different factory which has more precise equipment, that can have a lead time also. I used thin joint for our extension, and it was a joy to build.

Well that boiler lasted a long time, its leaked a LOT of water all of the baskets which were underneath it, ruined the lot, and has now had to be turned off. Honeywell diverter valve is leaking like mad. This hasn't started very well... Only 3 days old! Looks like ATAG after sales support is good, fella coming tomorrow to replace the part, always good to know the warranty stands for something

Never come across these before... thank you!

Fit them yourselves and save a fortune!

Right, we're setup now, they'd just not enabled the setting for DHW temp. Set a basic schedule up, which I'll tweak as time goes on.

Will do. I also have the benefit once we get the tado working, of setting the preheat tank up on a schedule, which will make things very flexible, so it doesn't have to be on all of the time.

Boiler is in, and all good, the amount of gas it uses at full pelt is surprisingly low compared to our old Ideal Isar, even though this is a 27kw and the old was 24kw, so hopfully it'll save us some money. Our only problem now is the Tado thermostat we had previously, i've connected it up to Opentherm, but it seems to have a mind of its own, setting DHW temp to 40C and CH to 80C, both of which are wrong for us, if I change them on the boiler, the tado changes them back, so I'm in touch with their support to see whats going on.

Yeah I thought it was decent, internet prices were showing between £2250 and £2500, so as soon as he said the price, he had the work, and we know him anyway from some friends that used him. Boiler is going in today! Be nice to have a warm wash again lol. This boiler has a DHW preheat tank, which can be turned off using the eco mode (back to how we always operated with the old boiler), I'm guessing the preheat is going to use marginally more gas than not using it? Would you have it on or off?