Your HEPA filters must be real ones. HEPA is just an acronym anyone can slap on anything, there's no accreditation.

Recent testing on the Vacuum Wars channel showed big differences between filters from the vacuum manufacturer and off-brand "HEPA" filters. Probably the same applies everywhere.

https://www.youtube.com/watch?v=eAIYRykQkMk

  >Your HEPA filters must be real ones. 

HEPA H13 only means the filter was tested to 99.97% particle efficiency at the most difficult particle size. There's nothing magical about this number. In reality air filters can often clean better with an E11 or E12 filter (tested to 95% and 99.5% respectively), because these filters allow much greater airflow from the same fan.[0]

Remember, the clean air is immediately mixing with the dirty room air. If you get twice the airflow while "only" letting 5% of particles through, that's a good tradeoff.

CADR (tested by AHAM, not just the manufacturer's claim!) is what really matters, not HEPA vs non-HEPA.

[0] https://x.com/Engineer_Wong/status/1899144721710408038

> HEPA is just an acronym anyone can slap on anything, there's no accreditation.

There are standards:

> Filters meeting the HEPA standard must satisfy certain levels of efficiency. Common standards require that a HEPA air filter must remove—from the air that passes through—at least 99.95% (ISO, European Standard)[4][5] or 99.97% (ASME, U.S. DOE)[6][7] of particles whose diameter is equal to 0.3 μm, with the filtration efficiency increasing for particle diameters both less than and greater than 0.3 μm.[8]

* https://en.wikipedia.org/wiki/HEPA

* https://en.wikipedia.org/wiki/HEPA#Specifications

Here in India you can usually tell them apart by whether they are advertised as HEPA vs "HEPA-type".