For medical air systems, which distance is the minimum from vehicular exhausts?

• A. 25 ft
• B. 15 ft
• C. 20 ft
• D. 10 ft

Answer: (A)

Keeping the outdoor air intake for medical air systems far enough from vehicle exhausts is essential to prevent contaminants from being drawn into the system. Vehicle exhaust contains pollutants like carbon monoxide and particulates that can enter the medical air supply if the intake is too close, posing risks to patients and staff. The minimum distance commonly required is 25 feet. This separation helps ensure exhaust plumes don’t get entrained by the intake, even when wind direction or speed shifts, and it allows dilution with ambient air before entry. Shorter distances—such as 10, 15, or 20 feet—do not provide reliable protection against backflow of exhaust contaminants, which is why 25 feet is used as the safe standard.