Grease duct

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 
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 
In many places, they will be constructed out of stainless-steel ductwork connected through a series of air filters 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. 

 Maintenance and cleaning 
These systems must be cleaned sometimes. Many will have certificates issued by the cleaning and maintenance contractors. Sunday, 2 May 2021 

Problems with hoods that are not taken care of include poor ventilation, excess heat and smoke, and the potential risk of fires.

 References 

 Other websites 

 UL treatise on wrapping systems
 NFPA 96: Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations 
 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

Category:HVAC
Category:Commercial kitchen equipment