Solexx Ventilation Universal Solar Powered Vent Opener
Without using energy, you may bring fresh air into your greenhouse.
The 24" x 12" louver vent is made of tough, outdoor-grade PVC and keeps the rain out while yet allowing enough of fresh air to keep plants healthy. Even when the greenhouse is closed, three louvers made of 5mm Solexx high density polyethylene allow diffuse light into the greenhouse. When you are away, the solar-powered option (pictured) automatically opens and closes the Louver. It's simple to incorporate into your custom-designed greenhouse.
HV-34-M Solar Louver (solar powered)