I did something quite like that too. My 2500 is enclosed in a cabinet as well with some large vent slats on the back, but nonetheless there wasnt' much airflow. I went to Target and bought a 3" or 4" fan for $5 and have it blowing cool air from the rear towards the front. It gives me excellent airflow and after being on all day, I can put my hand on top of it without getting burned.
The thing just runs hot.