3M 8511 N95 Cool Vent Plug and Cover

thingiverse

I had a box of 3M 8511 N95 masks for working around the house. These masks feature an exhaust port on the front that provides excellent comfort by allowing exhaled air to exit the mask while keeping the inside of the mask cool. However, this design isn't ideal if you're trying to curb a pandemic. My initial thought was to print a plug for the inside of the mask. The plug can be inserted slightly rotated to get the pins past the crossbar in the mask vent, turned to align the crossbar, and then pushed snugly into place. This solution works fairly well but doesn't give anyone any indication that the mask exhaust vent has been modified. The second part is simply a cover that fits snugly over the vent from the outside of the mask. The pressure seems to hold it on OK for now, but it may need to be modified with clips if it becomes loose over time. Please note that neither of these solutions creates an airtight seal and there will likely be some bypass exhaust air around either device. They will reduce the amount of unfiltered air exiting the mask. If the 3M 8511 mask is all you have available, these parts may help you to reduce the amount of unfiltered air emitted from the cool flow vent. Be safe and stay healthy.