If your basement is a finished area with no studs or joists exposed, I would think that a window fan would be the best option, along with a door open to the basement so that you have air moving through the basement out the window. I am assuming that you are following the precautions needed for a kiln, including distance from walls and ceilings, proper wiring, and general safety. I you still have the odor issue you may want to look into a fan with duct for a hood that is over the kiln and ducts out the window.
