Primary filters
Illustrated Guide to Ventilation (BG 2/2009), compiled by Kevin Pennycook and published by BSRIA in 2009, states : ‘Primary filters (Grade G1 to G4) have an average arrestance ranging from 50 – 90%. Average arrestance is the amount of dust retained as a percentage of the total load (a ratio). Primary filters can arrest particles down to 5 um but have a minimal effect on particles below 1 μm. Air velocity through primary filters is an average of 2 m/s, and the pressure drop rises from 10-60 Pa when clean to 125-250 Pa when dirty. These filters can be permanent and cleanable (made of foam or metal mesh) or disposable (made of a glass or synthetic media). Primary filters are mainly used to protect ventilation and air conditioning equipment (if building use does not require filtered air), or as pre-filters to extend the operating life of fine filters installed further downstream.’
--BSRIA
[edit] Related articles on Designing Buildings
Featured articles and news
Cladding remediation programmes, transparency and target date.
National Audit Office issue report on cladding remediation.
HBPT and BEAMS Jubilees. Book review.
Does the first Labour budget deliver for the built environment?
What does the UK Budget mean for electrical contractors?
Mixed response as business pays, are there silver linings?
A brownfield housing boost for Liverpool
A 56 million investment from Homes England now approved.
Fostering a future-ready workforce through collaboration
Collaborative Futures: Competence, Capability and Capacity, published and available for download.
Considerate Constructors Scheme acquires Building A Safer Future
Acquisition defines a new era for safety in construction.
AT Awards evening 2024; the winners and finalists
Recognising professionals with outstanding achievements.
Reactions to the Autumn Budget announcement
And key elements of the quoted budget to rebuild Britain.
Chancellor of the Exchequer delivers Budget
Repairing, fixing, rebuilding, protecting and strengthening.
Expectation management in building design
Interest, management, occupant satisfaction and the performance gap.
Connecting conservation research and practice with IHBC
State of the art heritage research & practice and guidance.
Innovative Silica Safety Toolkit
Receives funding boost in memory of construction visionary.
Gentle density and the current context of planning changes
How should designers deliver it now as it appears in NPPF.
Sustainable Futures. Redefining Retrofit for Net Zero Living
More speakers confirmed for BSRIA Briefing 2024.
Making the most of urban land: Brownfield Passports
Policy paper in brief with industry responses welcomed.
The boundaries and networks of the Magonsæte.