Greenhouses need to be designed to not only capture solar technology but also adequately Greenhouse Auto Vent ventilate extra 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 work really well as they are located where heat gathers naturally at the peak of the roof.
If vents in the roof are not possible, be sure to at least have a home window to two you may open.
Ideally you need 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 kind of heat gain and cool your greenhouse too much.
Which means you close the 
vents or windows during the night and what occurs another 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 is too cool.