accounting for a vapor barrier in calculating energy efficiency

[Anonymous]

Good day!

Sorry for my English, I write through Google translator

Tell me, does the building energy efficiency calculation tool take into account the presence in the vapor barrier cake?

According to my calculations, it should significantly affect heat engineering, but when the material is introduced into the multilayer structure, with the parameters of the vapor barrier, the picture does not change.

[Andy Thomson]

Airtightness is more important than a vapour barrier. You will see an infiltration rate for every unique opening and 'structure' in the ecodesigner dialogue. When you adjust or reduce these from their defaults, you will see a reduced heatloss from reduced air leakage or infiltration - and this is the ultimate purpose of any air barrier (or what you are calling a vapour barrier). Best, Andy