Automatic Vent Opener

The Automatic Vent Opener provides reliable, hands-free ventilation for greenhouses, high tunnels, cold frames, and other growing structures. Powered entirely by heat, it automatically opens and closes vents as temperatures change, helping maintain proper airflow without electricity.

Built with durable aluminum and stainless steel components, this low-maintenance vent opener features an adjustable opening temperature from 60°F to 75°F and opens vents up to 18". It is recommended for vents weighing up to 15 lbs.

Features include a quick-disconnect design for cold frames and dual springs for added stability in windy locations.

Replacement heat-activated cylinders are available separately.