A question regarding U-values

Mike-Graham

Yeah sorry, I was kind of getting at the fact that also in 10 years time, not only will products be better, but will also be a lot cheaper, as it'll be more mainstream.

I agree the airtightness factor is definitely something to think of. The whole interior of the building is getting a membrane for this, the large window has no openers so won't have an issue, but this bi-fold is the sticking point.

I have found a company, Lacuna, who do 0.73U whole unit, and class 4 airtightness, but i'm looking at £4k for what I need.

Smiley_Dan

Yep, tough decisions!

The U values, are they installed U values (Uw) or just values for the glazing (Ug)? I think you've said whole unit so I assume the former, but something else to consider for *all* quotes to make sure you are comparing them all in the same way.

Mike-Graham

Yeah I know about that trick, definitely the Uw values for everything.

Jwashbrook01

Schuco claim there door can go into Passivehaus. But there u-value states otherwise. You would be best with a aluminium wrapped timber or PVC, both costly though and to be honest not worth it. Stick some decent glass in there, double glazed works fine for UK weather. Weathered cill not flush fit.



James

Mike-Graham

lol, we've ended up going with a uPVC Bi-Fold, from Liniar, but this one has the Modlok kit on it, so its basically an aluminium bi-fold in terms of strength, but uPVC in terms of thermal ability and cost, 1.0U for around £2100

Smiley_Dan

Thanks for updating us. I'd be interested to hear about how you get on with the air tightness of that door Mike.

Mike-Graham

I'm awaiting the official test results back from the Manufacturer, but i'm seeing average results of 0.83ACH or Class3 airtightness, which is good enough. We went to see this door in person, and the seals are very good, very very good infact, I was very impressed. We've opted for the standard threshold, rather than low threshold, which gives us a third back seal on the internal side, which will improve airtightness. Will report when its in, in around 1.5months time.

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