If your gonna vent the space your using then a 265 or a 465 will work best for you! If you are gonna vent the tube? Then have it blowing ant the mogul end and exiting via a duct.The shorter the better!If it's flex then pull it tight! Less restriction that way.I use a 265 and a tempstat by my light hood and it only runs for about 5 mins. tops! I have a fairly large space,too! I'm about to post a pic for ya!

Ga Grown!