Where should return air not be pulled from according to mechanical regulations?

Return air should not be pulled from closets and garages due to potential contamination and safety concerns. Closets can harbor dust, debris, and pollutants that are not suitable for recirculation in an HVAC system, which could affect indoor air quality. Garages may contain fumes from vehicles, chemicals, or other hazardous materials that can negatively impact the air that circulates throughout the building.

Unlike living rooms, offices, or conference rooms where air quality can typically be maintained more effectively, pulling return air from closets and garages can introduce harmful elements into the HVAC system. Therefore, regulations often specify these areas as unsuitable for returning air to ensure a safe and healthy indoor environment.