Additional venting can be instrumental in a container that temperature is an issue.  Containers being closed up can accumulate a lot of heat from the sun, as well as moist air from the outside environment.  Our solar fan, which is installed above, can help regulate the heat by using the sun's energy to power this fan.  The fan exchanges the air in a 20' container 6 times in an hour, providing the sun is shining on the solar panel which is affixed to the roof.