What is required for using a corridor as a source of makeup air for exhaust systems?

Using a corridor as a source of makeup air for exhaust systems requires outdoor air supply because it ensures that the air being supplied is clean and has not been contaminated by indoor pollutants. The outdoor air brings in fresh air from outside, which can help to maintain acceptable indoor air quality and prevent negative effects associated with inadequate ventilation, such as increased levels of carbon dioxide or other harmful airborne substances.

When corridors are utilized for makeup air, it is critical to source this air from outside rather than recirculating indoor air. This practice aligns with building codes and standards designed to promote health and safety within the indoor environment. Outdoor air supply also compensates for the air being exhausted, helping to maintain proper building pressure and airflow dynamics.

In contrast, other options like return air or exhausted ventilation may lead to the recirculation of potentially contaminated indoor air, which would not adequately address air quality concerns and might violate mechanical code requirements. Fresh air exchange is a broader term that refers to the overall process of bringing in outdoor air, but the specific requirement in this context emphasizes the direct supply from outside to ensure quality and compliance.