This project is super cool! Great job so far.
I'm sure y'all have probably seen this already, but maybe someone else hasn't. Great closeups and different angles on some pieces:
https://www.youtube.com/watch?v=x1yRMxS7TT8
For the venting, what about a "mist humidifier"/"essential oil diffuser" like this:
https://www.amazon.com/BalanceFrom-...89094&sr=8-3&keywords=mist+humidifier+cycling
(I'm not affiliated in any way, nor am I promoting this particular item, just giving an example. Searching for "cycling mist humidifier" or "cycling essential oil diffuser" should get you in the right ballpark.)
The important thing is that many of these have an "intermittent mode" that mists for 20 seconds (or whatever - it varies by model), then is off for 10 seconds. May be a bit long of an "exhale," but you'd have something out-of-the-box that would give you a cyclic mist effect without a solenoid or any microprocessor electronics. Maybe you need to add a squirt gun nozzle to throttle the jet a bit and figure out some way to make sure the water inside doesn't spill out, but... can I say "that's
your problem" without sounding like a jerk?
Added bonus: You can put aromatherapy oils in it and each suit can have a different purdy smell.