Greenhouses need to be 
Greenhouse Auto Vent designed to not only capture solar technology but also adequately ventilate extra heat if temps get too hot.
You should always be sure you have sufficient vents in the roof of your greenhouse as heat rises and you want that heat to flee.
Greenhouse roof vents function really well because they are located where heat gathers naturally at the peak of the roof.
If vents in the roof are not possible, make sure to at least have a screen to two you can open.
Ideally you want to have cross ventilation therefore two windows on two sides of the greenhouse work best.
However you shouldn’t leave the vents or windows open at nighttime as you’ll lose any heat gain and cool your greenhouse too much.
Which means you close the vents or windows at night and what happens the next morning: you forget! At this point your greenhouse overheats and if you’re unlucky, you lose some plants.
Or you forget to close the vents at nighttime and your plant life suffer if the night is too cool.
