Greenhouses have to be designed to not merely capture solar energy but also adequately ventilate excess heat if temps 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 escape.

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

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

Ideally you would like to have cross ventilation therefore 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 heat gain and cool your greenhouse too much.

Which means you close the vents or windows during the night and what occurs the next morning: you forget! Right now your greenhouse overheats and if you’re unlucky, you lose some plants.

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