where to buy energy efficient fans?

where would be the best blace to look for energy efficient fans to vent my growing room? sears, lowes, menards. And for venting should it be pushing air out with a place for fresh air to come in, or blowing air in with a place for air to leave? Thanks

Idk if they even try to make fans 'energy efficient.' I guess it depends, how BIG u talkin? I mean, if it's the power bill ur worried about, the fan is small potatoes compared to all the lighting, and myself, i run a 5,000btu AC on top of everything. For venting, it is more 'efficient' to pull the hot air from the room, so if u don't got an intake and exhaust fan, then go with the exhaust fan up top, with a passive intake down low.