Alton | Thermofor Roof Vent Opener Piston Replacement leanto shed Regenerated Polypropylene

Regenerated Polypropylene

Commercial Grade - same materials used by professional growers

Slide it in the opening from the inside out

bolts and hinges made of stainless steel

Alton | Thermofor Roof Vent Opener Piston Replacement leanto shed Regenerated PolypropyleneThe Thermofor Long Piston Replacement is a direct replacement cylinder designed for Thermofor automatic roof vent openers used in Alton greenhouses. If your current opener is no longer responding properly to temperature changes, replacing the piston is a simple way to restore reliable, automatic ventilation. This heat sensitive cylinder contains a wax core that expands as temperatures rise and contracts as they cool, driving the vent to open and close