I was working with an air balancer yesterday for a project I can't talk about:
And it wouldn't work at all. Weird. I eventually found that mud wasps had made a nest inside of the ait inlet to the regulator, prompting me to tell the strange anecdote of the "wasp excluder" on the BOM at the old job doing brakes for trains.
Turns out, wasp excluders are patented,
https://patents.google.com/patent/US3957078
The more you know!
