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user-1137156 | Posted in Building Code Questions on

I’m likely to use the Panaonic ERV bath vent fan(s). Is it permissible to use the vented attic as either the source or destination of this kind of ventilator?

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  1. Expert Member
    Dana Dorsett | | #1

    Dumping humid bathroom air into the attic creates mold conditions. While it was once common to terminate bath fans into vented attics, that practice is now explicitly banned in most building codes.

    Pulling ventilation air from attics may be code-legal, but delivers any attic dust into the room. This can be a serious health issue where the attic has been previously insulated with asbestos laden vermiculite, or even with uncovered fiberglass (batt or blown.) Don't do it.

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