Eth0:2025 Autumn air purifiers

Active air filtration is being looked into by the orga.

Meanwhile, let's check how many visitors can bring their own purifiers along.

Name	Description	CADR in m3/h	Remarks
Juerd	TaoTronics AP-003*	350	Will move it to the (shared) bedroom at night
Juerd	Another TaoTronics AP-003	350
joepie91	2x IKEA FÖRNUFTIG	120 each	EPA12 filter; not certain yet whether I can come
you?	...	...

How much ventilation is needed?

The WHO has indicated that for gatherings, you need at least 10 dm³/s/person, which is 36 m³/h/person of ventilation. Real ventilation with fresh outside air is best, because it also gets rid of the CO2 and moisture. Unfortunately, many (most) buildings are equipped with substandard ventilation systems, and the standards (like the Dutch Bouwbesluit/Bbl) themselves do not meet the criteria.

If sufficient actual ventilation is not available, or just for extra risk reduction, additional air cleaning can be installed using (portable) air purifiers with HEPA filters. For scrubbing bio-aerosols like covid or flu, a lesser filter (e.g. G7 ≈ MERV13) would suffice, but most air off-the-shelf purifiers have much higher grade filters (which is unfortunate because with a lower grade filter, the same fan could have a higher airflow!).

Note: proper ventilation is necessary to enable self-protection with masks, and can reduce a super-spreader event to a much lower number of infections. It can strongly reduce the number of long distance infections, but it's less effective at very short distances. Ventilation is just one part of a comprehensive approach.