NBN EN 1366-1:2014+A1:2020

This Part of EN 1366 specifies a method for determining the fire resistance of vertical and horizontal ventilation ducts including those access panels, which are integral part of the tested ducts. The test examines the behaviour of ducts exposed to fire from the outside (duct A) and fire inside the duct (duct B). This Standard is used in conjunction with EN1363-1.

Annex A provides general guidance and gives background information.
This European Standard is not applicable to:

a) ducts whose fire resistance depends on the fire resistance performance of a ceiling or wall(where ducts are located in cavities enclosed by fire-resistant shafts or ceilings);
b) ducts containing fire dampers at points where they pass through fire separations;
c) one, two or three sided ducts;
d) fixing of suspension devices (e.g. anchors) to floors or walls.