Greenhouse Auto Vent Greenhouses have to be designed to not only capture solar energy but also adequately ventilate excess heat if temperatures get too hot.
You should always be sure you have adequate vents in the roof of your greenhouse as heat rises and you want that heat to flee.
Greenhouse roof vents function really well as they are located where heat gathers naturally at the peak of the roof.
If vents in the roof aren't possible, ensure that you at least have a windowpane to two you can open.
Ideally you would like to have cross ventilation therefore two windows on two sides of the greenhouse work best.
However you should not leave the vents or windows open at nighttime as you’ll lose any kind of heat gain and cool your greenhouse too much.
And that means you close the vents or windows at night and what occurs another morning: you forget! Now your greenhouse overheats and if you’re unlucky, you lose some plants.
Or you forget to close the vents at nighttime and your vegetation suffer if the night is too cool.