Thanks, everyone. I'd vented the moonroof, but that hadn't quite done it; I'll have to try cracking a window as well. SD Driver, I've found that using "defrost" turns either my heater or my AC pump on (depending on the weather), which is what uses the power. You're right that the fan doesn't seem to use much at all. I "discovered" this morning that selecting the "face" or "floor" vents, instead of the "defrost" vent, with the temperature at or around the outside temperature will help clear things up without using a lot of power. The fan is still a bit more than I need, but it is an okay compromise. That'll just be rough when the outside temperature dips down into the 30s again. Woo! If anyone else figures out passive air flow, please let us know. Thanks!