The S8 and S16 mini greenhouses are fitting with active ventilation, which pulls hot air out of the greenhouse when it gets too warm.
The S8 has one twin fan, and the S16 has two twin fans.
Summer mode
The fans turn on when the temperature rises above your chosen setting. They extract hot air from the top of the interior, while pulling cool air in from the back at the base.
Winter mode
The fans are unlikely to come on above the summer temperature (apart from perhaps those mild, sunny days) ... which means it's possible your plants will get too humid.
You can turn on "air recirculation" which runs the fans at a slow speed when they are not required for cooling. They will run for 5 minutes at the beginning of every hour, to remove stale damp air from the mini greenhouse.
Smart humidity control
With a future firmware update (free download for the control unit) we'll be releasing integration with our humidity sensors, to trigger the fans when humidity gets too high.