WUFI

Can https://meteostat.net/en/place/gb/exete ... 2024-10-04 be converted into a WUFI weather file (click the download arrow top left and choose a file format)? Is it sufficient?

Cool!

AFAIK the problem with Meteonorm is that it doesn't have driving rail data either

Good question.

I am not convinced it's correct to just apply a proportional area ratio, interpolating between the characteristics of 2 materials (90% plywood : 10% air in your case) to give characteristics of the composite. This is commonly done for composite U-values (brick and mortar, or ...

Is it too early to give an outline of what you're doing?

Morris,that is v interesting - are you going to do any testing/data creation? I hope that we'll get to hear about whatever you find! Might be worth a post on http://www.linkedin.com/groups?gid=4770 ... ps-b-grp-v

Good and important question. I often wonder what happens to 'breatheable' constructions when a few yrs later it gets redecorated with typical warehouse emulsion!

Perhaps a supplementary question is - what are the vapour permeabilities of typical commercial paints, or common-language paint types ...

What are the generally applicable guidelines for deciding whether the balances, and the no of convergence failures, are good enough? What principles - e.g. error 'not too bad' relative to what? I don't find any written advice that explains the principles (if any) and/or specifies the acceptable ...

pudding wrote:I've basically been checking that ... the RH in each layer never reaches 100%

AFAIK, you won't see RH reach 100% because in a porous solid some vapour liquidises at all RHs, and that ramps up exponentially as it approaches 97%. So 92% or thereabouts might be the RH limit to check.

pudding, barn in Cornwall - do you live there too? Me nr Exeter - how about seeing if we can find other users, maybe a local users group?

Hi Dan, and anyone else

What I'd like to do would be to compare genuine UK/Ireland weather files with same location as generated by Meteonorm, to see just what patterns there may be in the differences - and therefore what rule-of-thumb corrections might be applied to Meteonorm files.

Christian ...

Daniel, perhaps this seems like a minority concern, but many designers and builders want to move away from reliance on mainstream plastic membranes and tapes, even (or particularly) 'intelligent' ones, and rely, principally, on OSB or similar, instead: there are reports of excellent air tightness ...

Christian - it's valuable that you posted the 2 weather 'pictures for Holzkirchen (measured vs Metonorm), side by side. Yes, we can see the difference in driving rain, which you say is important.

But most of the other parameters seem to be significantly different too - yet you say all the rest is ...

Well, the IPC model may correspond to measured reality under assumed 'typical' conditions, but I have everyday, non-exotic conditions for which it cannot be right.

AFAIK, IPC looks at

1) small all-over leaks in the air barrier due to joints (e.g. taped seams) and fixings (e.g. staple holes);
2 ...

At recent Training, I understood Christian to say that this whole infiltration/air permeabilty question was of great importance, that it is being researched and worked upon by Fraunhofer, that new more quantifiable approaches are being designed to replace or supplement the preliminary IBP ...