这个绝对是违规的，你可以自己查International Residential Code
M1507.2 Recirculation of Air
Exhaust air from bathrooms and toilet rooms shall not be recirculated within
a residence or to another dwelling unit and shall be exhausted directly to
the outdoors. Exhaust air from bathrooms and toilet rooms shall not
discharge into an attic, crawl space or other areas inside the building.
