What is the term for the air supplied to maintain negative pressure in a containment area?

What is the term for the air supplied to maintain negative pressure in a containment area?

• A. Exhaust air
• B. Makeup air
• C. Return air
• D. Fresh air

Answer: (B)

Maintaining negative pressure in a containment area relies on makeup air that replenishes air exhausted by the ventilation system. In negative‑pressure spaces, air flows from surrounding areas into the containment while the exhaust removes air from inside. To keep the pressure differential, you must continuously supply air to replace what’s being exhausted, and this supply is called makeup air. It’s typically conditioned and filtered before entering to avoid carrying contaminants with it. Because makeup air is the specific source added to compensate for exhaust, it best describes the air used to sustain the negative pressure. Exhaust air is the air leaving the space; return air is air returned to the HVAC system; fresh air is general outside air and does not inherently capture the controlled supply used to balance negative pressure in a containment area.

Maintaining negative pressure in a containment area relies on makeup air that replenishes air exhausted by the ventilation system. In negative‑pressure spaces, air flows from surrounding areas into the containment while the exhaust removes air from inside. To keep the pressure differential, you must continuously supply air to replace what’s being exhausted, and this supply is called makeup air. It’s typically conditioned and filtered before entering to avoid carrying contaminants with it. Because makeup air is the specific source added to compensate for exhaust, it best describes the air used to sustain the negative pressure. Exhaust air is the air leaving the space; return air is air returned to the HVAC system; fresh air is general outside air and does not inherently capture the controlled supply used to balance negative pressure in a containment area.