To determine whether an HEPA filter needs to be replaced, it’s quite simple. I’ll present you with a straightforward method that can be applied directly on-site without the need for complex instruments. Line workers will understand it easily.
\n1. The most intuitive and quickest method (without instruments)
\n– The wind speed has significantly decreased
\n– Turn on the fan and place your hand at the outlet. You’ll feel very weak and soft wind
\n– Before it was strong, but now it’s noticeably weaker \u2192 It’s likely clogged
\n– The dust in the operation area has increased
\n– More dust is falling on the tabletop and samples
\n– The colony count and contamination rate have risen \u2192 First suspect that the HEPA filter has failed
\n– The usage time has exceeded the limit
\n– In a regular laboratory: \u2265 2 years
\n– In a workshop with excessive dust and poor environmental conditions: \u2265 1 year requires a focused check
\n– The primary filter is already very clean, but the wind speed is still low
\n– The primary filter has been washed or replaced, but the wind speed still cannot increase
\n\u2192 The blockage is in the HEPA filter, not the primary filter
\n2. Precise determination using instruments (the most standard)
\n1. Wind speed detection (most commonly used)
\n– Normal outlet wind speed for horizontal laminar flow cleanroom:
\n0.3 – 0.6 m\/s
\nJudgment:
\nContinuous multiple readings < 0.25 m\/s \u2192 Must replace the HEPA filter
\n2. PAO\/DOP leak detection (most authoritative)
\nLeakage on the filter surface \/ frame
\nFilter efficiency is lower than 99.97% @ 0.3 \u03bcm
\n\u2192 Replace immediately
\n3. Check for the following situations, replace immediately without hesitation
\n– The HEPA filter is deformed, damp, moldy, or damaged
\n– The filter paper is cracked, de-laminated, or leaking air
\nThe cleanliness test has been continuously unqualified
\n– After replacing the primary filter and cleaning the duct\uff0c the wind speed still does not meet the standard
\n– The usage time exceeds 3 years and has never been replaced<\/p>","protected":false},"excerpt":{"rendered":"
To determine whether an HEPA filter needs to be replaced, it’s quite simple. I’ll present you with a straightforward method that can be applied directly on-site without the need for complex instruments. Line workers will understand it easily. 1. The most intuitive and quickest method (without instruments) – The wind speed has significantly decreased – […]<\/p>","protected":false},"author":3,"featured_media":4254,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[92],"tags":[],"class_list":["post-5218","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry-technology"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/posts\/5218","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/comments?post=5218"}],"version-history":[{"count":1,"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/posts\/5218\/revisions"}],"predecessor-version":[{"id":5219,"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/posts\/5218\/revisions\/5219"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/media\/4254"}],"wp:attachment":[{"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/media?parent=5218"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/categories?post=5218"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bacintl.com\/fr\/wp-json\/wp\/v2\/tags?post=5218"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}