These “Vari-Cyclone” ceiling fans from FanWorks are perhaps the most efficient ceiling fans available. The fans utilize what Fanworks calls “Gossamer Wind” blade design technology, which is said to deliver 40% more air flow without any increase in power use. They also run on DC power, which also adds to their efficiency when off-grid power is used.

On the advantages of running under DC power, Fanworks says:

The average AC-powered ceiling fan draws between 0.5 and 1 amp. When an inverter is used to run the AC ceiling fan, you are pulling 5 to 10 amps DC to run the fan. This does not include the power consumed by the inverter to produce the AC power required by the ceiling fan.

The Vari-Cyclone, DC-powered ceiling fan, runs directly from your battery bank, no inverter required, and draws only 0.5 amp @ 12 VDC, making the Vari-Cyclone 10 times more energy efficient than an AC-powered ceiling fan.

Here are some stats:

Power Consumption: (with 3-blade configuration):
At 12 volt: 60 rpm, 7 watts, 2500 cfm.
At 24 volt: 120 rpm, 27 watts, 3400 cfm.

You can see a very in-depth analysis of the performance of these fans here.

Homepage: FanWorks

Available from: Survival Unlimited ($175-$195)

If you look closely you can see a dog being cooled by this Endless Breeze fan. These portable 12V fans plug into a cigarette-lighter style plug. They only draw 2.58 Amps when on high speed.

See more info here. They are available from Amazon for $60. Thanks for the photo Brenda.

These Endless Breeze fans are powerful,
portable, high volume 12 volt fans with a twelve inch blade that operates
at three speeds. Air movement of up to 1000 CMF (cubic feet per minute)
is a major breakthrough in 12 volt portable fans. Standing
only fourteen inches high on retractable legs and less than three inches
thick it travels and stores easily. It weights under five pounds.

Power Consumption:
Low: 1.18 Amps
Medium: 1.62 Amps
High: 2.58 Amps

Available from: Amazon ($60)
or Pplmotorhomes.com ($62.95)