Models DWKL and SWKL are intended for use in connecting Type 1 and 2 kitchen hoods, cooking ovens, and heating or hot water appliances to the outdoors.
UL-1978 Standard, Grease Duct – under this Listing, Models DWKL, DWKL-Lt, SWKL, and SWKL-Lt have been determined suitable for Grease Ducts as defined by NFPA-96, the “Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations”. UL confirmed proper minimum air space clearance to combustibles for 500°F continuous exhaust gas temperatures and 2000°F exhaust gas temperature for 30 minutes simulating a kitchen exhaust fire. UL also confirmed that the installed joints are grease and smoke tight.
See UL Listings and Clearances sections for maximum temperatures and required clearances to combustibles at different operating temperatures.