Greenhouses have to be designed to not only capture solar technology but also adequately ventilate extra heat if temperatures 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 escape.
Greenhouse roof vents function really well because they are located where heat gathers Greenhouse Auto Vent 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 therefore two windows on two sides of the greenhouse work greatest.
However you should not leave the vents or windows open at nighttime as you’ll lose any heat gain and cool your greenhouse an excessive amount of.
Which means 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 and your plants suffer if the night time is too cool.