Air infiltration from outside

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Sandberg
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Air infiltration from outside

Post by Sandberg » Tue Nov 22, 2022 6:33 am -1100

Hello,

how should I model air infiltration from outside? Thank you.

Daniel
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Re: Air infiltration from outside

Post by Daniel » Mon Nov 28, 2022 4:26 am -1100

Dear Mr. Sandberg,

from German practice we know, that the amount (sum) of infiltration moisture during winter lies roughely in a range between 50 and about 300 g/m². This can be evaulated by transient models which consider the influencing factors like air tightness, critial air flow paths, temperature gradients between indoors and outdoors etc. It can - in dew point calculations - also be considered as a fixed additional drying potential of 250 g/m² and year.

If you look for moisture infiltration from outside, you can currently use the source which distributes of a fixed amount of moisture over the resp. months (summer months). If the amount of 250 is appropriate, or due to the higher moisutre level in warm regions in summer, an increased amount of 500 or 750 g/m² makes more sense we cannot answer. I don't know any publications or investigations dealing with these amounts.

So I think, it depends a bit on your question! To verify the drying potential, you can just use such sources to check, what is still accepable.

best regards
Daniel Zirkelbach
Dr.-Ing. Daniel Zirkelbach, Deputy Head of Department Hygrothermics, IBP Holzkirchen

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