How do your greenhouses vent themselves during the warmer months?

Each Solar Gem Greenhouse is equipped with an automatic vent (our medium and large greenhouses have two) that opens and closes though the magic of beeswax!  Our vent controller opens and closes by the expanding and contracting of beeswax located within the control arm.  When the interior temperature reaches approximately 75 degrees Fahrenheit, the beeswax expands and the pushes the control rod, which opens the vent. When the interior temperature drops below approximately 70 degrees Fahrenheit, the beeswax contracts and the control arm closes the vent.  It’s simple, and simply amazing!