why run the air-cooled lights thro the filter? i run the the filter and the hoods on two separate fans, the aircooled hoods pull clean, cool air from outside the room and push the same clean warmed air back out, as the air has not come from the room it doesn't need filtering...

As M_C said tho you don't really wanna be pushing hot air thro your fan unless said fan is built for that kinda abuse.. filter, fan, hoods if you don't want to run two fans