In a multi-hood installation, what is the purpose of a common plenum?

In a multi-hood installation, what is the purpose of a common plenum?

• A. Houses electrical components
• B. Drains condensate
• C. Balances airflow and smooths distribution to each hood
• D. Filters grease

Answer: (C)

In a multi-hood setup, the common plenum acts as a shared air reservoir that balances and smooths airflow to every hood. When multiple hoods feed into one duct, each hood can impose different demands on the system due to cooking load, hood size, or duct length. The plenum provides volume and a uniform pressure region so the exhaust from all hoods reaches the fan with similar flow, preventing one hood from starving or overpowering the others. This keeps the capture velocity consistent across hoods, reduces pressure and velocity fluctuations, and lowers noise and vibration. It’s not the place for electrical components, condensate drainage, or grease filtration—the latter are handled by filters at the hoods and dedicated filtration sections.

In a multi-hood setup, the common plenum acts as a shared air reservoir that balances and smooths airflow to every hood. When multiple hoods feed into one duct, each hood can impose different demands on the system due to cooking load, hood size, or duct length. The plenum provides volume and a uniform pressure region so the exhaust from all hoods reaches the fan with similar flow, preventing one hood from starving or overpowering the others. This keeps the capture velocity consistent across hoods, reduces pressure and velocity fluctuations, and lowers noise and vibration. It’s not the place for electrical components, condensate drainage, or grease filtration—the latter are handled by filters at the hoods and dedicated filtration sections.