The air removed by every mechanical exhaust system shall be discharged ________.

The correct answer is that the air removed by every mechanical exhaust system shall be discharged outdoors. This requirement is based on safety and code compliance, ensuring that contaminated, stale, or heated air is expelled from the building.

Discharging air indoors could lead to the accumulation of harmful pollutants or odors within the space, compromising indoor air quality. Similarly, directing exhausted air into a basement or an attic is not compliant as it could create pressure imbalances or lead to the recirculation of exhausted air, both of which can be detrimental to the overall ventilation system and air quality in the building. Therefore, directing exhaust air outside is essential for maintaining a healthy and safe indoor environment and is aligned with the standards set forth in the International Mechanical Code.