Rion Automatic Greenhouse Vent Opener

The Rion Automatic Greenhouse Vent Opener automatically controls the temperature in all Rion greenhouses. As the air inside the greenhouse warms, the vent gradually opens to allow the correct amount of airflow into the greenhouse and closes when the optimal temperature is reached. The vent arm is electricity free. It uses a natural wax that expands as the air gets warmer, pushing a piston that raises the window and contracts as it cools, closing with the use of a spring. Works with all Rion greenhouses.