The amount of makeup air is what in relation to the exhaust air in a kitchen exhaust system?

• A. Make up air should be equal to exhaust air
• B. Make up air should be greater than exhaust air
• C. Make up air should be less than exhaust air
• D. There is no relation between makeup and exhaust air

Answer: (A)

To keep the space balanced, the amount of makeup air should match the exhaust air. When the hood vents air out, an equal amount of outdoor air must be supplied to the room so the pressure stays neutral and the indoor environment remains comfortable. If makeup air is too little, negative pressure can pull in unconditioned air, odors, or moisture from around cracks and fittings. If makeup air is excessive, positive pressure can push conditioned air out and waste energy. In practice, makeup air is sized to roughly equal the exhaust rate and is often tempered or conditioned to fit the space’s comfort needs.