Hybrid Respirator Uses Repurposed Filters

With the coronavirus raging worldwide, 2020 has seen major shortages of personal protective equipment impact healthcare workers and individuals alike. This has led many to improvise their own solutions. One of the more complete offerings we’ve seen is this hybrid respirator build from [Ben Howard].

[Ben’s] build goes above and beyond the usual craft project masks. It uses a laser-cut chipboard frame to fit three HEPA filters, originally designed for the Roomba robotic vacuum cleaner. Two are used for exhalation, while one is used for inhalation. A small blower fan is installed with the intake filter, to provide mild positive pressure when breathing in. The assembly is wrapped up in fabric, using layers of spandex, fleece, and ripstop nylon to provide the best possible seal against the wearer’s face.

It’s a build that should appeal to those who want to breathe cleaner air and also protect others from exhaled particles that can spread respiratory viruses. We’ve seen all kind of masks hit the scene this year; the graphene-impregnated variety is one of the more interesting designs. Still, one can hope that future years lead to less reliance on such measures!

15 thoughts on “Hybrid Respirator Uses Repurposed Filters

  1. All these interesting stories about making masks to prevent yourself from dying are like the “heartwarming” stories about people with deadly diseases raising money for their treatment by crowdfunding. Yes, it’s good. But it’s also terrible. We shouldn’t have to be making things like aerosol blocking masks, parachutes, or the seat belts for our cars. It’s all feasible but these should be completely standardized with long term contracts to factories like Ameritechs and 3M’s so they can hire the workers necessary to actually produce *real* masks for everyone.

  2. It looks like that mask has a large inside volume, which is bad because it raises CO2. Exhaled air can have 50000ppm of CO2. While in rest, like sitting at a desk, tidal volume during breathing is only about 500 ml. This means that if your mask has a dead space volume of 100 ml, you’re breathing in 20% old air, with average of 10000 ppm of CO2, which can have impact on your health and cognitive capabilities.

    1. With the fan running it’s drawing in room air and purging the mask volume continuously. Not likely to have any significant CO2 buildup. That also draws many times the necessary air volume through the filters reduces operating life. But, there’s no testing and no real citation of standards. I’ve frequently found that buying or building proper test gear for a project was a huge effort. More than the project itself. This needs some pretty non-trivial test gear. How often does the filter media need to be changed? According to what standards or tests? Every hour? Daily? Once a century? What’s the cost to build one? What is the operating cost? How well does the seal work? How do you know? What happens when you talk or cough? According to actual tests, does it really work better than a 25-cent disposable mask? It’s not a bad effort but there are too many issues.

      1. Sure, the stale air can’t get out but the viruses can get in. “I’m suffocating because it won’t let in a molecule 10,000 times smaller than a virus!!!” Take your dumbassery to parler.

        1. Don’t pretend you can’t smell the difference when you take off a mask. I never said I was suffocating, I just like breathing air directly, which is why I don’t wear a mask unless someone is willing the call the cops on me over it.

    1. Also, who has done the relevant research on HEPA filters to see if they’re even effective at all against the virus? Can we even compare them directly against surgical masks or N95?

    2. I’ve wondered about a few concerns also like fiberglass or other materials physical separation, and not just the effusia, that can be a health risk too.

      My thought is have a post medical grade CPAP filter for the particulates with the PAPR designs I’ve been iterating through.

      I’ve read some concern regarding ozone from the motors that are brushed… though thinking is negligible… though maybe not in your face?

      Just picked up a really gross 3M M100/200 painters PAPR that uses some different style GVP filter that I’ll be working on an adapter for next.

      Figure will coordinate with the full face mask snorkel welding PAPR I’ve been working on where the last piece of the puzzle is determining which filters to use. Conical cylindrical looking vacuum HEPA in a HDPE pipe section adapted or an air purifier rectangular HEPA design in like a food container adapted or maybe just stick with a few HEPA CPAP filters adapted. Then use a carbon filter or activated carbon section for the organics post the HEPA filter with most likely a pre-dust filter and if working with materials like paint… and cover over the filter to catch more liquid particles.

  3. for my experience i must say that i love to wear mask, somehow it managed to enhance my stamina, now i can
    walk up some high places without heavy breathing, so its cool :) also my mask is homemade so it is very comfortable

  4. UV illuminated sponge-like titania nanostructures (foams) make the best antiviral filters because they are self cleaning, and by clean I mean that they cannot host accumulations of viable viral particles.

      1. Yes, and it surprises me that they are not just telling everyone to drop their weight and live healthy lives to minimise their risk. Nothing about 2020 makes a lot of sense.

        1. Prior to the abomination period, seems the quote from Thomas Edison regarding disease prevention through healthy lifestyle was the best medicine, was the doctrine more propagandized for positive health.

          “โ€œThe doctor of the future will give no medicine, but will interest his patient in the care of the human frame, in diet and in the cause and prevention of disease.โ€

    1. Was looking at the Thorlo non-Thorlon material socks since I’m allergic or sensitive to orlon-acrylic and found they have a CuTECยฎ Copper Ion Technology material.

      Further research I found the same material is used in a mask that is on the market and can be found here: https://www.ebay.com/itm/Washable-Reusable-Copper-Cloth-Face-Cover/124513818020

      I also found a silver material called HydroPurยฎ and an even more “advance” zirconium phoshate zirconium phosphate-based ceramic ion-exchange resin containing silver called AlphaSanยฎ RC 5000 by Milliken. Reads like the Delcron HydroPur polyester combines both.

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