4 ms·
I don't think this has been mentioned on this thread yet: If you live in a place where air pollution is a concern, one solution to this issue is to buy a HEPA a
by dcx 8y ago
I don't think this has been mentioned on this thread yet: If you live in a place where air pollution is a concern, one solution to this issue is to buy a HEPA air filter. These filters are designed to trap a significant quantity of precisely the types of particles that air quality studies examine (2.5-10µm coarse dust particles and <2.5µm fine particles).
> "To qualify as HEPA by industry standards, an air filter must remove (from the air that passes through) 99.97% of particles that have a size greater-than-or-equal-to 0.3 µm." [1]
[1] https://en.wikipedia.org/wiki/HEPA https://en.wikipedia.org/wiki/HEPA
- amluto 8y agoThat’s only helpful while you’re at home. Also, the obsession with HEPA and its 99.7% reduction of the relevant particles seems silly to me. For a filter that recirculates air, the relevant figure of merit is the rate at which dirty air is replaced with clean air, which is roughly the air flow through the filter times the efficiency. So a 90% efficient filter with 50% more airflow is better. For a stand-alone unit, the “clean air delivery rate” is a more sophisticated measurement. You can do very well by upgrading your HVAC filter to MERV 13 or better and running the fan for a few hours a day. But check with an HVAC contractor before you change filter types — it may affect the overall performance of the system. For an outside air intake, the efficiency does matter, and HEPA is a good idea.