Remember I suggested inverse square law for decay of laminar flow,
@sameo416? The area of cleaner air should be also shrinking by distance.
Thank you for reviewing it. This is very well said. I appreciate that.
The Fit Factor is composed of two parts: particles that penetrate through the filter material itself, and particles that leak in from the gaps.
For an N95 respirator, the filtration efficiency is extremely high. Therefore, its Fit Factor is primarily driven by the latter—leakage. However, for an air purifier employing a lower-grade filter, its inherent ability to remove ultrafine particles is limited. Consequently, when using the Fit Factor metric, the resulting number does not represent the leakage rate for such devices.
A simple test demonstrates this: if you perform a Saccharin Sodium qualitative fit test on a surgical mask and an AirFanta Wear that happen to have the same Fit Factor value, you would directly taste the intense sweetness through the surgical mask. Under the protection of the AirFanta Wear, however, you would detect no sweetness, as shown in my video.
Thus, a surgical mask and an air purifier with the same Fit Factor do not provide equivalent protection against viruses. In fact, at a 0cm distance, our device may show a Fit Factor of 6.3, yet laboratory tests at the same 0cm distance confirmed a 100% virus filtration rate and a 99.9% bacteria filtration rate, on low speed.
This proves that the Fit Factor of 6.3 originates almost entirely from the penetration of non-viral ultrafine particles through the filter medium, not from leakage. Reproducing this with live viruses is challenging and requires a high-containment lab. However, if a Saccharin Sodium qualitative test were conducted, the conclusion should be consistent.
Base on that, I made a table show the real leakage rate, base on your result.