Secondary filters
Illustrated Guide to Ventilation (BG 2/2009), compiled by Kevin Pennycook and published by BSRIA in 2009, states: ‘Secondary filters (classes F5 to F9) have an average efficiency ranging from 40 – 95%. Average efficiency is defined at the weighted average of the efficiencies for the different specified dust loading levels up to final pressure drop. The air velocity through the filter media is typically 0·02 – 0·1 m/s. Secondary filters are effective in trapping pollen, bacteria and dust. Secondary filters can be of the extended media bag type, pocket type or a rigid bag.’
--BSRIA
[edit] Related articles on Designing Buildings
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
Your views needed - a strategy for the professions, trades and occupations.
Confronting competency, codes, capacity and costs.
The hidden risk in modern construction supply chains.
Construction Management, 10 June
24 months to 14: CITB launches accelerated apprenticeships.
Bridging the gap between clients and contractors
Concerns remain around contractor quality, capability, and delivery.
Construction Management, 10 June.
Heat pumps beat boilers in new home tests.
Building Safety Act implementation in Wales
CIAT to host industry panel on 26 June.
New and updated CLC building safety guidance.
New UK National Buildings Database.
Building Safety Wiki Interviews
Chief executive of the British Woodworking Federation.
Planning condition discharge in England and Wales
A brief explanation from a building compliance expert, with further links.