need help cooling growdrobe (wardrobe)

Draw air from the cold outside if you can. Ducting isn't very efficient at channeling air, despite the fact that it's made for that purpose. The inside has lots of ridges for the air to catch on. Use straight hard tubing whenever possible and use long, slow-curving elbows to maximize airflow. The straighter the airway is, the faster the air will move. Check the intake and exhaust openings to see what kind of air you're moving. What kind of fan are you using? Centrifugal fans are usually far superior to others. Some good brands are Can-Fan and Vortex.

its nearly summer where i am so its real hot outside 2 if i get air from out side wont that make it twice as hot?