Is it true or false that air that is exhausted must not be recirculated?

• A. True
• B. False
• C. Depends on the situation
• D. Only during certain conditions

Answer: (A)

The assertion that air that is exhausted must not be recirculated is true. When air is exhausted from a space, it generally carries with it various contaminants, including odors, moisture, and potentially harmful airborne particles. Recirculating exhausted air back into the indoor environment can lead to poor air quality and health issues for occupants.

In HVAC systems, proper ventilation requires that fresh outside air be brought in to replace the exhausted air. This not only helps maintain healthy indoor air quality but also ensures that the HVAC system operates efficiently. Exhaust air should be directed outside and not reintroduced to the indoor environment, as doing so would defeat the purpose of exhaust ventilation, which is to remove indoor pollutants and maintain a balanced air system.

While there may be specific applications or engineered systems designed for air recovery (like energy recovery ventilators), the general principle remains that exhausted air, which is laden with contaminants, should not be recirculated back into the living or working space.