Liz, Robbie, Carlton, Diane, Andy, Eric, Steve, Chuck, Arthur, India - THANK
YOU very much for your feedback on your experiences with fogging - and your
offers to test beta prototypes when I have them!
Thanks to you, several things are now perfectly clear to me:
(1) Fogging is always worse when wearing a balaclava or other lower-face
protection
(2) There are three causes of fogging when wearing such protection:
(a) Exhaled air rising up on the OUTSIDE of glasses/goggles
(b) Exhaled air rising up on the INSIDE of glasses/goggles
(b) Sweat/moisture from tears and skin around the eyes condensing
INSIDE glasses/goggles
(3) Thus solving the problem requires the following:
(a) Port exhaled air well away from glasses/goggles
(b) Prevent exhaled air from leaking up behind lower-face protection to
inside of glasses/goggles
(c) Actively defog the inside of glasses/goggles
My first attempt at a solution resulted in some progress, but significant
improvements are needed before I have a beta-prototype to offer you for
testing failed. I experimented with a half-facepiece respirator (3M 7500
series) without any filtration. It has two inlet valves, one outlet valve,
and a "snout" over the outlet valve which points downward and opens up at
chin height.
The facepiece directed exhaled air far enough away from my glasses to not
cause any fogging (which is a BIG help!) It fit snugly enough to my nose
and cheeks to preventing exhaled air from leaking upwards to the inside of
my glasses. However, the valves impeded my breathing far too much when
pedaling hard. It was impossible to fit my glasses comfortably on the nasal
bridge of the device. The "cheeks" on the facepiece restricted my field of
vision too much - I couldn't see my handlebar-mounted rear-view mirror.
Lastly, I still had fogging inside my glasses from sweat around my eyes.
All told the fogging problems were significantly reduced, but the other
things are show-stoppers.
What next? I think I have designed a lower-face protection device which
will meet criteria 3a and 3b. No valves are needed so restricted breathing
won't be a problem. That leaves defogging for the glasses/goggles. For
evaluation purposes I obtained some ski goggles with a fan (Smith Prophecy
Turbo) and they look like a step in the right direction.albeit with some
serious problems. The main one is that field of vision is much too
restricted. They are quite expensive, and if one wears glasses in addition
to the goggles, then one is looking thru TWO surfaces - which leads to
another set of problems. I've been researching paintball masks with
ventilation fans, and I will score one on eBay if I can get it cheap. I've
also purchased a micro-fan (25 mm square by 6 mm thick!)
More to come. This is fun! I'm hoping I can come up with something
patentable - I want to make some money from this. If it works, it will have
many more applications than winter-bicycling. I would be interested in
collaborating, should any of you be so inclined. I am very adept at
mechanical design (I'm a mechanical engineer) but I need help with
electrical/electronics, testing, the patent process, sourcing, marketing.
Hans Noeldner
<http://www.entropicjournal.blogspot.com> www.entropicjournal.blogspot.com
Oregon, Wisconsin
608-444-6190
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