Granary - Built in the 1850s using a technique on the interior called brick noggin to protect against air infiltration.
Since buildings are not totally sealed (at the very minimum, there is always a ground level entrance), the stack effect will cause air infiltration.
XPS type is highly resistant to air infiltration.
The reduction of air infiltration within an earth shelter can be highly profitable.
Spray application provides even better protection against air infiltration and improves wall rigidity.
Landlords here are required to provide smoke detectors, and maybe they should be required to reduce air infiltration.
Dehumidification of humid air infiltration can waste significant energy.
In addition, wet-spray allows for an even better seal of the insulated cavity against air infiltration and eliminates settling problems.
When improperly installed, they are prone to air infiltration; especially if the ductwork is located in an un-conditioned space.
Is this not what causes cold air infiltration ?