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Personal Air Filters

battery powered personal air filters to make or buy

Sometimes we need to bring our own air filters. #BYOHEPA

These portable solutions will not clean entire spaces well enough to drop other precautions like masking. The physics of air movement make it difficult to recommend reliance on a personal air filter for safety, as blowing clean air can bring some contaminated air with it. Consider it an additional layer of protection in addition to a well fitting respirator and proper ventilation whenever possible, especially where appropriately sized HEPA filters are not in use. Consider adding eye protection if blowing air directly at your face.

Travel DIY air filter

In the spirit of the Corsi-Rosenthal Box, @SharonBurnabyBC came up with a winning combination of a small, rechargeable battery operated fan, and round HEPA filter of similar size. Important to this combination of parts is access to the power button and recharging port once the filter is attached, as many fans place the on/off button and USB port in the back, where it would be inaccessible once taped to the filter. The two HEPA filter options listed below have been tested and fit with this fan.

A 1cm “shroud” covering the perimeter of the face of this fan is suggested.

DIY personal air filter

Parts list:

USB Rechargeable mini fan (This mini portable fan can last 9 to 42.5 hours with fan only – The working hours based on different speed)

True HEPA filter (US) (closed bottom) (Rosewill brand) – if sold out, look for 7-8inch wide round HEPA filters (can try LEVOIT core 300s replacement filter, solid bottom, 7.48 inches)
True HEPA filter (Canada) (this one has an open bottom, so cut a piece of cardboard or foam board to cover the opening)


Optional: Powerbank for adding run time if needed.

Optional: Mesh drawstring bag for ease of carrying and lower profile. Can be run right within the bag, this one is tested to fit with the US filter.


The Wynd is a powerful portable HEPA filter, at around $130 range. It moves a lot of air but is louder than the DIY portable filter. It fits in mesh water bottle pockets on backpacks, and air flow is adjustable.

Wynd portable air filter

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