Until now, separating the good air filters from the bad ones has been difficult since test methods have not produced clear results. During the past 20 years two test methods have been applied: Eurovent 4/5 and EN 779:1993. These methods were the best available to determine filter performance but were never truly correct. Now they are definitely antiquated.
The European air filtration industry has now reached an agreement to revise tests and an improved test method, Revised EN 779:2002, is being applied as of 2003.
Filters in reality
Despite their simple appearance, air filters are actually a complex product. Without providing an unnecessarily high amount of resistance, filters must let a sufficiently large flow of air through their media while simultaneously removing harmful airborne particles that might cause problems for both people and HVAC plants. Testing in accordance with a particular norm, called Revised EN 779:2002, now reveals how a filter will later perform in an actual ventilation plant, as the test procedure simulates ”real-life” conditions in the laboratory.
Positive consequences of the method
Revised EN 779:2002 provides more knowledge about the performance of filters and makes it possible to:
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evaluate filter performance properties in relation to Indoor Air Quality (IAQ) requirements and process demands.
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find better agreement with lab test results and actual installations.
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obtain a faster, simpler method that is easier to understand.