Texas prepper used a device that heats oil inside the cylinder from harbor freight when the green house goes above 80 automatically opening a window. Here is a similar vent opening device https://www.amazon.com/Univent-Automatic-Vent-Opener-Standard/dp/B0036EJ9HW/ref=asc_df_B0036EJ9HW/?tag=hyprod-20&linkCode=df0&hvadid=229436034656&hvpos=1o4&hvnetw=g&hvrand=7205760638535088934&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9023955&hvtargid=pla-391312863769&psc=1
Here’s the description
Ingenious temperature-sensitive devices automatically open and close cold frame lids, greenhouse windows and even skylights throughout the day and maintain a constant interior climate, something impossible to achieve by manual adjustments. Requires no batteries or electricity, it starts opening between 55—75°F, depending on how you have adjusted the vent. Strongly recommended for all our glazed season extenders because it dramatically improves plant growth. Screw directly into polycarbonate panels, wood, or metal frames. Use the Standard Vent Opener to lift up to 15 lbs, and the much stronger Gigavent, with all metal construction, to lift up to 65 lbs.
Features & details
Solar Vent Opener can lift up to 15 lbsStarts opening between 55 - 75°F, depending on how you have adjusted the vent.Screw directly into polycarbonate panels, wood, or metal frames.
Product Dimensions11.8 x 2 x 2 inchesItem Weight14.4 ouncesShipping Weight14.4 ouncesManufacturerAgriculture Solutions LLCASINB0036EJ9HWManufacturer referenceUniventCustomer Reviews4.4 out of 5 stars 229Reviews