Greenhouses have to be designed to not only capture solar energy but also adequately ventilate extra heat if temperatures 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 work 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 home window to two you can open.
Ideally you would like to have cross ventilation so two windows upon two sides of the greenhouse work greatest.
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 an excessive amount of.
And that means you close the vents or windows during the night and what happens another morning: you forget! Today your greenhouse overheats and if you’re unlucky, you lose some plants.
Or you Greenhouse Auto Vent forget to close the vents at nighttime and your vegetation suffer if the night time is too cool.