I would use a fan between the can and the lights and another one after the lights.

During the winter, you can be energy efficient and duct the exhaust into another room to help cut down your heating bill.
redline Reviewed by redline on . Carbon Filters and Air Cooled Lights I have a 400 cfm fan with a Carbon filter can. I've read that I can use the can fan with the air cooled lights. I was thinking of using the can/fan as the intake and blow out through the lights. Question is will this single fan/can combo be strong enough to cool two 1000w with cool tubes without an extra booster fan to help pull air out at the outake? If I ever decided to add another 1000w MH would this one fan handle 3? I hear MH is hotter than HPS. The ducting would all be in one Rating: 5