True or False: Ventilation air can be re-circulated from one dwelling to another.

The correct answer indicates that ventilation air should not be re-circulated from one dwelling to another. This is primarily due to health and safety regulations that aim to prevent the spread of contaminants, odors, and pathogens between different spaces. Each dwelling typically has unique air quality needs and concerns that must be managed independently to ensure a safe environment for its occupants.

Re-circulating air can lead to cross-contamination, which can affect indoor air quality and possibly lead to health issues. This practice is generally discouraged in residential and commercial HVAC design and guidelines, as it can compromise the effectiveness of individual ventilation systems. Additionally, local building codes and regulations often prohibit or restrict such practices.

While some might consider filtering air before re-circulation as a potential solution to protect indoor air quality, even filtered air can still carry allergens and pathogens that differ between residences. Local regulations might also provide specific guidelines that further restrict or detail how ventilation air can be managed between dwellings. Overall, maintaining separate ventilation systems for each dwelling ensures better control of air quality and occupant safety.