Greenhouses need to be designed to not only capture solar energy but also adequately ventilate extra heat if temperature ranges get too hot.
You should always make 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 are not possible, make sure to at least have 
a windows to two you may open.
Ideally you would like to have cross ventilation so two windows upon 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.
Which means you close the vents or windows during the night and what happens the next morning: you forget! Today your greenhouse overheats and if you’re unlucky, you lose some plants.
Or you forget to close the vents at nighttime and your plants suffer if the night time is too cool.
Are you interested in Greenhouse Auto Vent?
