Quote Originally Posted by Opie Yutts
Can you vent into the crawlspace or attic? You really need to get that hot air out of there, or consider flourescent lights.

Or try this: get a fan that is dedicated to blowing the space between your light and plants, and get a big ice block, set it in a big bowl and put it in front of the fan. Or just set a couple of ice blocks near your plants. They may last all day that way and decrease temps a few degrees. I've recently thought about trying something like this. I'll let you know how it works if I come up with something.
Like similar to a swamp cooler? That probably would lower temps. If you try this I would like to see. I'm also curious as to what effect this would have on humidity. Without proper exhaust I don't think that water vapor will be going anywhere. Be careful for mold/mildew, I know that can be an issue with swamp coolers sometimes. If you try it, keep us updated please .

WeedyBoyWonder: Can you post any pics of your closet. Sometimes it's easier to figure out a solution if you can see what you're working with. Also, how stealthy does this need to be?