I've got my two cooltubes hooked to one 6" vortex inline 470cfm fan. With all the twists and turns and carbon filter, I'm guessing the cfm is down to around 400cfm. The tubes stay cooler than a cfl. I've got one plant touching the cooltube directly under the bulb and it isn't hurting the plant. My fan is on the exhaust side of the tubes - sucking air.

Dayum - why so much for shipping? Where do you live, at the North Pole?