US Patent Issued to ROCKWOOL on March 11 for "Fire resistant ventilation duct and a method of manufacturing and installing such ventilation duct" (Danish Inventors)

ALEXANDRIA, Va., March 12 -- United States Patent no. 12,247,689, issued on March 11, was assigned to ROCKWOOL A/S (Hedehusene, Denmark).

"Fire resistant ventilation duct and a method of manufacturing and installing such ventilation duct" was invented by Kurt Munk Pedersen (Hedehusene, Denmark), Jurg Dieter Stefan Rodenberger (Hedehusene, Denmark) and Markus Thoma (Hedehusene, Denmark).

According to the abstract* released by the U.S. Patent & Trademark Office: "A ventilation duct for a fire rated ventilation duct wall penetration has one or more metal sheets forming said duct, wherein said metal sheet duct is covered on the outside by a heat insulating material, and said duct includes elongated stiffening members located on the outside of...