A grease duct is a duct that vents flammable vapors from commercial cooking equipment such as stoves and deep fryers to the outside of the building. It will normally be connected to an exhaust fan .

Fire hazard [ change | change source ]

Vapors are created when grease is heated to and beyond its vaporization point . When it cools, the grease will condense on colder surfaces. Grease is a flammable hydrocarbon .

Design [ change | change source ]

In many places, they will be constructed out of stainless-steel ductwork connected through a series of air filter s which will be pulled by a fan and exhausted outside. They will also often have some form of fire damper in this ductwork connected to the fire alarm system. ^[1]

Maintenance and cleaning [ change | change source ]

These systems must be cleaned sometimes. Many will have certificates issued by the cleaning ^[2] and maintenance contractors. ^[3]

Problems with hoods that are not taken care of include poor ventilation, excess heat and smoke, and the potential risk of fires. ^{[4] [5]}

References [ change | change source ]

Other websites [ change | change source ]

Wikimedia Commons has media related to Category:Kitchen exhausts .

• UL treatise on wrapping systems
• NFPA 96: Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations Archived 2013-05-02 at the Wayback Machine
• ASTM E2336 Standard Test Methods for Fire Resistive Grease Duct Enclosure Systems
• ISO 6944-1:2008 Fire containment -- Elements of building construction -- Part 1: Ventilation ducts