In this study, two experimental series have been conducted, to investigate clogging of ventilation filters with fire smoke. In the experiments, fire smoke was drawn through a ventilation filter and it was measured how quickly the filter clogged.
In most experiments that were carried out, it took about an hour before the filter was clogged, but there were also experiments where the filter was clogged within a few minutes. This shows that clogging can happen very quickly.
It is thus necessary to secure the smoke an alternative route outside the filter if it is necessary to maintain a certain amount of air in the ventilation system in the event of a fire since the ventilation filter can become clogged within a few minutes.
The study is funded by Omsorgsbygg Oslo KF, Undervisningsbygg Oslo KF, Sykehusbygg HF og and the Norwegian Building Authority (DiBK).
You might also be interested in the newly started follow-up project on the same topic, with the same name (link
Full report in Norwegian with English summary (pdf