What is the role of a make-up air system in a kitchen exhaust setup?

• A. To replace exhausted air with outdoor air to maintain pressure balance and occupant comfort
• B. To humidify outdoor air before it enters the space
• C. To filter grease from air before it enters the space
• D. To reduce noise from the exhaust system

Answer: (A)

The main job of a make-up air system is to bring outdoor air into the space to replace the air that the kitchen exhaust removes. This keeps the area from becoming negatively pressurized, which helps prevent doors from slamming, drafts, and drawing in unconditioned air from adjacent spaces. It also supports occupant comfort and energy efficiency by balancing the air flow as the hood continuously exhausts hot, greasy air. In kitchens, this replacement air can also be conditioned and directed to where it’s needed, and it can provide combustion air for appliances, but the core purpose is to replenish the exhaust air to maintain proper pressure and comfort.