well you have a little bit larger room than mine because mine is a small cabinet but just keep in mind that light cant travel around corners, i seen this youtube video where this guy built some light trap boxes and i redid his idea, im sure you can up the scale and do your own even bigger.....i have these small PC fans ive encased with believe it or not foam posterboard...
build a small square with 4 wall around 6 inches high all around the fan.then inside this makeshift box start hot glue gunning baffles insides where air can travel around but not light, like staggerred pieces, so the air has to snake around. first two small vertical walls so there isnt a piece of foam board right against the face of the fan, then a horizontal wall, then another small vertical wall, then horizontal, etc...after 3 of these NO light can pass thru, make sure is flat black foam board... (make sure the fan is pointed in the right direction)...it sounds very diy but this stupid little light box can be made around any cfm, any size square shaped fan in theory....mine are 110 cfm and relatively quiet and transfer alot of air, hope this helps... heres some pics of what they look like...(in these pics i know their are ducts attached but this was a recent change and the original idea has no back face board, its just open, ive added ducts cause i had to cool my hood DIY style and also i got better exhause from the big silver ducting rather than just an open end...)