Constantly trying to improve energy efficiency inside today's airtight houses makes the air stale, so homeowners are going to great lengths to freshen their indoor environments with high-tech heat exchangers and air purification systems. But French designer Mathieu Lehanneur and Harvard scientist David Edwards decided to take a more natural approach, using a mobile greenhouse they call Bel-Air to purify and oxygenate the air the same way it's been done for eons.

The Bel-Air greenhouse takes an active approach to air purification, taking in stale air and forcing it through its three natural filters consisting of the plant's leaves and roots as well as a humid bath of water. Not only does it bring more oxygen and moisture into the room, it's also aesthetically pleasing at the same time. Prototypes are now for sale, and the device's creators will be showing it at the Museum of Modern Art in New York in February, hoping to market it by 2009.

Dezeen, via Gizmodo