Even in the winter, greenhouses in full sun can get pretty warm. Ventilation is a key component to greenhouse success. In Arkansas, cooling a greenhouse will be more critical than heating a greenhouse. Automation is the way to go, unless you never plan to leave your greenhouse alone. Basic options in cooling are to either reduce the amount of light coming in during the summer or venting.
Many greenhouses use both they have vents and they use a shade cloth for cover.
Some newer operations actually allow for the sides to be raised for extra ventilation. Back to Top Options You can have vents on the top, or on the sides, or both. Exhaust fans also help a great deal. Evaporate cooling systems work well. In evaporative cooling, they use corrugated cardboard or synthetic fiber pads.