heres what i did
i dont know if you have a dark spot to do it.
i got an emergency blanket wrapped it around my lights
and i run an old school 18" lakewood box fan on low you can see the bowing from the breeze.
the lights im using are a 150w and a 250 w hps. the blanket was 3 bux at target but you can get them cheaper at wally world.
and yes i have a big dark area to do it in. the size area i am running is 2'x3'.
the shape of the blanket guides the air up to the lights and out of the hut through the top.