Core77

Don't let its size fool you--the latest product from Big Ass Fans, the 8- to 10-foot ISIS model, can reduce energy bills by 25-50%, yet typically uses the same amount of energy as a refrigerator bulb. How do they do it? It's engineered to be lightweight through the judicious use of aluminum, yet the large fan blades still provide plenty of oomph.

If the protagonist from Up had inverted a bunch of these and attached them to his roof, he wouldn't have had to mess with those balloons....