What is the minimum clearance required from the duct or exhaust fan to the interior surface of combustible enclosures?

The minimum clearance required from the duct or exhaust fan to the interior surface of combustible enclosures is specified as 18 inches in the NFPA 96 Standard. This clearance is crucial because it helps to prevent the risk of fire caused by the heat generated by the exhaust ducts or fans. The thermal energy produced during cooking operations can be sufficient to ignite combustible materials if they are placed too close to these heat sources.

Maintaining an 18-inch clearance minimizes the risk of heat transfer to nearby combustible surfaces, which is a key safety measure in commercial cooking environments. This distance is a standard guideline intended to ensure that adequate air circulation is maintained, reducing the likelihood of localized overheating. Using this standard contributes to the overall fire safety strategy within commercial kitchens, reinforcing the importance of adhering to prescribed clearances for effective fire protection and ventilation control.