I can buy a ceiling fan from Home Depot capable of moving 5,000 CFM of air for about $50, and it uses a mere 50-60 watts while doing it. By contrast, most furnaces seem to have blowers that operate in a much lower CFM range but use humongous 1/2 or 3/4 horsepower motors that use 600 watts or more when energized.
How does this make any sense? Why is a 1/2 horsepower motor or larger were required for a furnace or central AC but a ceiling fan can get away with such a smaller, more efficient motor and move more air? Or is a ceiling fan CFM not the same as a furnace blower CFM? Is it that the blower requires a much higher RPM to push the air through the ductwork, so the blower CFM is more like a "delivered" value rather than a "supplied" one?
Is it possible to replace these beasts with more efficient versions? Do such things exist?