Greenhouses need to be designed to not only capture solar energy but also adequately ventilate excess heat if temps get too hot.

You should always make sure you have sufficient vents in the roof of your greenhouse as heat rises and you want that heat to flee.

Greenhouse roof vents function really well as they are located where hot air gathers naturally at the peak of the roof.

If vents in the roof are not possible, ensure that you at least have a windowpane to two you can open.

Ideally you want to have cross ventilation so 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 heat gain and cool your greenhouse too much.

Which means you close the vents or windows at night and what happens the next morning: you forget! Now your greenhouse overheats and if you’re Greenhouse Auto Vent unlucky, you lose some plants.

Or you forget to close the vents at nighttime as well as your vegetation suffer if the night is too cool.