ToughButterCup

Exactly. Make yourself - politely - a difficult target. Very politely.

Yes. I had a close look with a graphics package. The hole - and more importantly its position - might be: might be suspicious. Where's the path in relation to that 'feature' ? If it's not a hole, but a sheet of plastic (DPM ?) , is the DPM the vector for the water from a leak source elsewhere ? Leaks are worse than having a truculent tenager in the house. Much worse.

Hello. Welcome. Tell us a bit about about the research you have done for yourself: who have you talked to , what research have you done on your LPA website, what professional advice have you sought? I ask, because - as written - you give us precious little information to go on.

Cor blimey mate: nerdish this place innit? I mean '... focal acidosis ...' I read fecal acidosis. 😔 Can't help it....

I knew it ! Gottcha! You're one of those Bad Boys.

Ditto.

@Pocster, Just in case you haven't. ... ?

I've dedicated my life to that skill....

Thanks very much Terry. This thread is about cashflow, not so much about MVHR. I know I HAVE TO have it. Now that I have some, I begrudge the money especially when the house appears to perform really quite well on its own.

450 ppm or less (I think). Window always open on tilt : better put - rarely if ever shut. The wind direction and open-window/door configuration is very important. The chimney effect is very noticeable Sensor positioning appears to be important - I have found 'dead spots' in our house. As I write this at my desk (a dead spot) its 775 - with a 3m window wide open 4 meters away. Bedroom seems to be 'OK' to the extent that I can tell. The CO2 meter needs an a/c socket nearby, so the test hasn't been as extensive as I would like (flex length). The only time I've noticed a 'red' alert ( on the meter) is when over Christmas the house was packed with friends and family, cooking on full blast and some people were vaping like it was going out of fashion. I think that MVHR might well lessen the number and extent of dead spots. It'll be interesting to do a comparison. The question is how to do a fair comparison? Because for six or seven months of the year we have at least two windows open. Maybe @SteamyTea or @TerryE could help my thinking process with a 'fair' design ? Please? The main point is I realise that our approach is not for everyone: most want to switch MVHR on - forget it - and pay the bill. But until recently we couldn't afford MVHR, and so have been forced to experiment and 'feel' what the house will do for itself. To me, it seems to do better than I expected : slow temperature change up or down, and to an extent sauerkraut resistant. It is very clear though we have to open a combination of doors and windows every day. Whereas with MVHR we wouldn't need to think about it.

And let the smog-filled air into your Berlin high-rise ? There's a standing joke in Berlin ... Stossluften (shock ventilation) is really about neighbours being able to chat to one another: Old Mother Schmidt opens her window wide, puts a cushion on the window shelf, and hoists her décolletage onto a longsuffering cushion, bangs on her neighbours window. Frau Dumke (old Berlin name) opens her window, stands on a chair, sticks hers out of the window too : both of them put the world to rights. I'll spare you the teenage jokes about that process. No wonder they cant use MVHR properly. They open the window to talk to one another. Not because their flat is chock full of sauerkraut and the consequent farts.

That folks, that's no rant. From an ICF builder (as in DIY MAX) All of that is plain simple truth. No rant.

Can see you didn't pay attention during the training session - it's MIDDLE finger (longer reach)

Financial arrangements made in respect of a lawful build have nothing to do with anyone other than the contractor and customer.

Yeah ! Fab idea, lets all go round to @Pocster's and piss on his gatepost. @Pocster provides the beer all night.....

... with leak disclosing dye in it? 😑

Leak disclosing dye?

Here's too much detail. Fill yer boots. Here's the best answer: top company , sensible prices. Accurate, efficient quick

Thanks very much for the link. Really interesting

Re 1: I time my farts for bath time. Blowing bubbles is my one totally innocent pleasure : Debbie has had to remind me that the sound insulation between the floors is not good enough to do that when we have guests Re 2: Now that Mr Stewart has given me two brand new hips I'm back into having baths. Bath for increased blood supply to the new bits of metal and ceramic followed by a very hot shower Re 3: Bang on. The German ...luften... ( to blow the room through with clean air ) is hard-wired. My Berlin- based family is still doing it , mind you there's a massive (wood and - if you can get it- brown coal fired ) tiled furnace in the cellar. The chimney sweep signs it off every year as emissions compliant [It isn't] . Its hotter than the engine room on a Clyde Puffer. Re 5+6 , wellllll.....

Yes. I measure the CO2 levels constantly. I move the monitor around and peek at it now and then. This is in the office right now. I hardly ever look at the numbers: I look at the light. Yes, on occasion its red. Ooop North we don't fuss about stuff like that . A wide open window sorts that out during the #2 process. Saves on Fart Spray too. Large windows in each bathroom. Open for a few minutes. I've hidden the bathroom windows behind cladding (with 12mm gaps) so the windows can be wide open - so our cheeky bits are hidden . Exactly right. In any wind and rain direction we always have a down-wind window: mostly there's one window open. But, on occasion all the windows are indeed closed. When I'm away, well, I just don't care ..... But you are right, there are a couple of nights when we don't have our bedroom window wide open. Our Wintergarden roof overhangs the bedroom window by 3 meters, so our room is protected under that and some large vertical louvres. What Kevin WhatHisFace calls a Breeze Corridor. Folks, I'm just feeling mean. I know MVHR is A-Good-Thing. Well, I'm told it is😜 Call it Concerned Impecunious Old Age.

Well yes OK, for sign off I do. But Hell, after 4 years without MVHR ( first fit already done) - and now for the first time able to afford the box (second fit) .... I'm feeling like its a waste of money. Well if not a waste, then I begrudge the money. Doors and 3 meter slider open April to September. I think I might only be using it for three or at thee most 4 months of the year. Grrr. I know, I know. 😑

Mate, you need a surgeon .....😔

I've a teenager who turns up on a Saturday : picks his nose incessantly and tells me while attempting to mix mortar - straight-faced - that "This shovel doesn't work ... " So I tell him we need 2 buckets of sharp sand, and 2 of 10mm pipe bedding , and another single bucket with cement. " But you've not got enough buckets for all that " Imagine the innocent pleasure to be gained from watching him pick his nose again after putting his fingers in the cement ... "Soft stuff this cement innit ...... " I've never seen a teenager do a war-dance before. Twat. Followed by me shoving his head in a bucket of cold water. According to him, my shovel works now.

I don't think it matters much. The thing is not to allow 'dead air' in that space. Think shoes after a day's wear - no matter how clean they are, they'll still be holding moisture, and thus bacteria that tend to whiff a bit.