Recently questions about whether spread of heat and smoke in ventilation ducts during a fire represent an increased risk for personal safety and loss of properties have been raised. The technical solutions currently used to fulfill the pre-accepted performance given in the guidelines to the building regulations with regard to fire protection of ventilation ducts are largely based on descriptions in SINTEF's Building Design Sheet 520.352 on fire- and smoke protection of ventilation systems, and in BV Netts Guide for fireproof ventilation, also known as the BVNett Guide. This topic was once again raised in connection with the revision of the 2017 edition of the building regulations, when it was pointed out in inquiry statements that the pre-accepted performances are insufficiently defined and that the solutions outlined in the Building Design Sheet and the BVNett Guide are not sufficiently documented.

In order to elucidate this topic and provide scientific documentation on the extent to which the spread of heat and smoke in ventilation ducts represents a risk to persons and properties, the BRAVENT project (Fire and smoke spread in ventilation ducts) was initiated.

The project investigates issues related to heat dissipation in ventilation ducts, clogging of filters in ventilation systems due to smoke, the effect of the seal-up strategy with respect to pressure build-up in the fire room and smoke spread through leakages in the construction.

The objective of the sub-task presented in this report was to:

Compile a theoretical basis for the experiments and analyzes to be carried out.

1. Map relevant regulations for fire protection of ventilation systems.

2. Map standards that are the basis for determining the fire resistance of components included in a ventilation system.

3. Map the state-of-the-art regarding a. the need to fire insulate ventilation ducts.

b. the need to install bypass channels to prevent the filter systems from being clogged by smoke particles.

c. the effect of installing fire dampers in all fire-partitions with respect to smoke spread.

d. how smoke can be spread via ventilation ducts and leaks in the building structure.

e. the pros and cons of seal-up and extraction strategies.

© RISE Research Institutes of Sweden

This is sub-report 1, which summarizes the relevant, fire-related theory and state-of-the-art in the focus area. The report serves as the theoretical basis for planning of experiments and for the other activities in the BRAVENT project.