My application is composting with worms outdoors inside an a styrofoam cooler. I use a heat lamp and a thermo-electric cooler to maintain the temperature in the bin when the temperature outside is out of bounds for healthy worms. When the temperature outside is in bounds, I'd like to exchange the air in the bin with fresh air from outside, but I don't want to permanently compromise the insulating properties of my bin with lots of air holes. So I'm looking for actuator solutions that would allow me to open/close a window of sorts. I'm considering a solenoid air valve but I don't necessarily need/want an air compressor - a simple fan is sufficient to circulate the air. Any suggestions?

  • $\begingroup$ Do you need your container to be airtight or watertight or none of the above? $\endgroup$
    – George ZP
    Jan 11, 2016 at 6:25
  • $\begingroup$ It doesn't need to be strictly airtight or watertight. I just want to minimize thermal losses while closed. $\endgroup$ Jan 11, 2016 at 17:25

1 Answer 1


This is no question of robotics... Keep it simple (:

Google for "Louver Bath Vent": https://www.google.de/search?q=Louver+Bath+Vent

These kinds of ducts open by the air pressure generated from a ventilator.

  • $\begingroup$ +1 for this, a self-closing gravity grille (I don't know the proper name) to let the air out and a fan + small inlet to draw the air in. When the fan is not running the grille will close and there will be very little air exchange with the outside. No need for an extra actuator. $\endgroup$
    – Andy
    Jan 11, 2016 at 8:00
  • $\begingroup$ I like this idea, and will probably mark as accepted shortly. I'm just having trouble finding something off the shelf in the smaller size I was envisioning. The smallest dampers / louvers I've seen are 4 inches and I'm not certain they are self-closing. I was hoping for something closer in size to CPU fans, so more like 1 to 2 inches. I might try to fashion something similar myself using a weighted flap of insulating material. $\endgroup$ Jan 11, 2016 at 17:22

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