Lifetime you got any pics..it would help. I made a guy a cabinet that came out pretty good using 4 CFL's but the one im working on now has 12 CFL's and its about 15 inches deep, 30 inches wide and stands about 4 feet tall. Im thinking heat will be an issue but havent gotten to the temp testing stage. You want to keep your intake near the floor as the air is cooler but the exhause should be at the top since heat rises. It also sounds like you carbon scrubber is blocking your airflow, you may want to try a more powerful exhaust fan to pull through the scrubber, and rposition you fans accordingly. I'll post some pics later of the one in progress that I am constructing. Hope this help.