Science Technology Best Cooling Fans for a Good Night's Sleep By Christine Lepisto Writer St. Olaf College University of Minnesota Christine Lepisto is a chemist and writer from Berlin. A former Treehugger staff writer, she now runs a chemical safety consulting business. our editorial process Christine Lepisto Updated October 11, 2018 Migrated Image Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy Good things come in threes. TreeHugger recently reviewed the Bedfan and SunFrost Sleep Genie. The Bedfan cools you under the sheets while you sleep. The Sleep Genie is sized to cool just your sleeping area by insulating around the bed ("Victorian bed curtains" suggests TreeHugger's Lloyd Alter), and could be solar-powered. Making it three, we mention the Sleepbreeze Personal Cooling System. The Sleepbreeze cooling fan sips just 4 watts power, and a timer option gently slows the fan to a stop (so you won't awaken at a sudden change) after 15, 30 or 45 minutes if you choose. Sleep Fan Pack Sack and Battery Power Accessories The sleepbreeze collapses to pack away in a 14 x 14 x 13 cm (5.5 x 5.5 x 5.1 inches) pack sack. A battery power accessory is also available. Be sure to use the best rechargable batteries. The image at the top of this article shows the duct tied up to demonstrate its flexibility, but normally you would just align it with your body and let the cool air flow. Which is the Best Cooling Fan for a Good Night's Sleep?How do all the cooling fan or air conditioning options stack up? Here are some examples -- based on the most energy efficient models in each category: The Sleepbreeze personal cooling fan: 4 watts The Bedfan, recently featured in TreeHugger: 10 watts Ceiling Fan: 7 - 112 watts, depending on low/med/high speed and fan choice(1) Desk fan: typically 60 watts(2) The SunFrost mini-air conditioner, recently reviewed in TreeHugger: 72 watts. Low enough to be powered by a 280-watt solar array. Air Conditioner Room Unit: 470 watts(3) (2) Very lazy cite: from Sleepbreeze FAQ page. Worth a visit for a chuckle about the frequent questions the inventor's daughter asks. (3) Calculated for the smallest room unit (under 5200BTU/hr capacity) air conditioner in EPA's Energy Star Rating program for air conditioners. (Several models from Comfort Aire, Crosley or Danby rated best, at 13% better than Federal standards). A large unit (over 20,000BTU/hr) can run up to 2947 watts (Danby Designer DAC10033TW); the most efficient in the Energy Star Program runs at 1834 watts (Admiral AAW-05CR1FHUE).