While the drips don't seem like much, they really add up. Microsoft reports that their 46,000 square meter offices in Herzliya, Israel, collect 3 million liters of condensate from air conditioners annually, which it uses to irrigate the campus flora and cool the building.

This equates to the entire annual indoor and outdoor water needs of at least two family homes.

In the U.S., a campus building at Rice University, Houston, has an A/C unit that generates 15 gallons of condensate per minute, and they believe their entire campus could supply 12 million gallons annually.

Grasping this potential, municipal governments and eco-conscious offices around the United States are experimenting with different ways of utilizing a resource which for many years has served only to drip down the walls of buildings, giving them a dirty run-down appearance.