A building engineers’ ability to reduce pathogen transmission in existing buildings are limited by the original design of the mechanical systems, the original installation achieving design intent, and proper maintenance by a skilled, trained, and certified technician. Two of the approaches that a building engineer has at their disposal to reduce pathogen transmission are pressure barriers and airflow distribution.

This white paper discusses the pros and cons of using the cavity above a finished ceiling as a return air plenum combined with supply air to the air handler as a proper ventilation technique.