A mechanical outside air intake must be located a minimum of 10 feet below a source of contaminant located within 3 feet.

A mechanical outside air intake must be located a minimum of 10 feet below a source of contaminant located within 3 feet.

• A. 10, 3
• B. 10, 5
• C. 3, 3
• D. 3, 10

Answer: (A)

Outdoor air intakes must be kept clear of nearby pollutant sources to avoid drawing contaminated air into the building. When a contaminant source is close enough—within 3 feet—the intake has to be placed at least 10 feet below that source. This vertical separation reduces the chance that exhaust or released contaminants at the source will be entrained by the intake air. So the required arrangement is a 10-foot vertical distance below the source, with the source located within 3 feet of the intake. That combination matches the scenario described. The other pairings don’t satisfy this proximity rule because they don’t provide the necessary vertical clearance when the source is that close.

Outdoor air intakes must be kept clear of nearby pollutant sources to avoid drawing contaminated air into the building. When a contaminant source is close enough—within 3 feet—the intake has to be placed at least 10 feet below that source. This vertical separation reduces the chance that exhaust or released contaminants at the source will be entrained by the intake air.

So the required arrangement is a 10-foot vertical distance below the source, with the source located within 3 feet of the intake. That combination matches the scenario described. The other pairings don’t satisfy this proximity rule because they don’t provide the necessary vertical clearance when the source is that close.