Commercial Kitchen Ventilation
This drawing shows a commercial kitchen with a typical kitchen ventilation system consisting of a roof mounted CUBE upblast exhaust fan and a Model RSF supply fan.
Exhaust fan variations include the model CWB sidewall exhaust fan (also shown) when penetrating the roof is not practical. The Model SWB utility blower is recommended when higher static pressure capability is required to pull exhaust through long duct runs (typically 3 stories or more).
Fan Sizing
Exhaust
When not specified by local codes, the following guidelines may be used to determine the minimum kitchen hood exhaust cfm. Some local codes require 100 cfm/ft.2 of hood area for wall style hoods.
Supply
Recommended supply airflow is 90% of exhaust cfm. The remaining 10% of supply air will be drawn from areas adjacent to the kitchen, which helps prevent undesirable kitchen odors from drifting into areas such as the dining room.
| Type of Cooking Equipment | cfm/ft.2 of Hood | |
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Light Duty | Oven, Range, Kettle | 50 | |
Medium Duty | Fryer, Griddle | 75 | |
Heavy Duty | Charbroiler, Electric Broiler | 100 | |
Static pressure typically ranges from .625 in. to 1.0 in. for 1 story buildings.
NFPA Considerations
The National Fire Protection Association specifies minimum distance criteria for restaurant exhaust and supply fans as shown below:
10 ft. Horizontal Separation
1. Roof deck to top of exhaust fan windband - 40 in. min.
2. Roof deck to top of curb - 18 in. min.
3. Supply fan intake - 10 ft. min. from all exhaust fans.
3 ft. Horizontal Separation
For applications where the 10 ft. horizontal distance cannot be met, vertical separation between exhaust and supply must be at least 3 feet.
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