[qpiox]

> it provides a static pressure of 7.63 mmH2O, which is very high.

Actually, it depends on the specific HEPA filter if that is enough or not. If it's not enough, the air will find the path of less resistance and circulate in and out thru the fan blades, but not thru the filter.

For some HEPA filters you can find specs. These (https://www.airclean.co.uk/download/4724) are spec to 250 Pa which would be about 25 mm H2O if I am correct.

[maxerickson]

Even if they don't recirculate, I sort of doubt that these small fans are going to achieve sufficient air flow through the filter (a radiator is much less of an obstruction than a HEPA filter).