Greenhouses need to be designed to not merely capture solar energy but also adequately ventilate extra heat if temps 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 because they are located where heat gathers naturally at the peak of the roof.
If vents in the roof aren’t possible, make sure to at least have a screen to two you may open.
Ideally you need to have cross ventilation so two Greenhouse Auto Vent 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 an excessive amount of.
So you close the vents or windows during the night and what happens 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 as well as your plants suffer if the night is too cool.