Building Codes and Inspections/Apartment complex shared air


I have serious cat and dog allergies and am wondering about shared air via bathrooms in an apartment complex.  I'm wondering if when apartment exhaust fans are switched off if the air between apartments in the column is likely to be closed off by flaps of some sort.  In other words, how much do you think I would need to be concerned about animal dander from a lower or higher apartment contaminating my place?  (I love animals but this is what it is.) I would much appreciate your feedback.  Thank you.

The exhaust fans will many times have a flapper in the exhaust side to prevent air movement when the unit is not turned on, and some apartment units have rooftop central exhaust fans that maintain a constant negative pressure on the roof for air changes and to prevent exhaust from one unit from going into another. Fire dampers were presumably installed where required by code at the time the building was constructed or last renovated, but they're not designed for the purpose you indicate.  The building's owner should have plans that better describe the features of the building. Important to you will probably be the air filtration system used in the circulating air system of the building, which I have no way of knowing.  

Finding a building where the heat and air conditioning air circulation system limited to your individual unit with a good air cleaner/filter is probably in your best interest if you are very sensitive.

Building Codes and Inspections

All Answers

Answers by Expert:

Ask Experts


Keith Fuller


I'm an ICC Certified Master Code Professional fielding general building code questions. My experience has been heavy in fire related issues.


I've been employed since 1985 as an inspector and plan reviewer, and am a municipal Assistant Building Official and Deputy fire Marshal. I've had fire service experience since 1972, having served as a three time Fire Chief and Fire Marshal in years past. The increasing workload, mandatory certifications, and continuing education requirements in recent years have caused me to concentrate my efforts on code related issues. I hold national fire service certifications as well.

ICC Master Code Professional

©2016 All rights reserved.