If you’ve ever reached for your water bottle on a long, hot ride only to have an empty water bottle sputter in disappointment, listen up. Kristof Retezár, a design student from Vienna, is developing a self-filling bike water bottle that sucks water right out of humid air.

It’s called Fontus and the concept is simple: it condenses moisture out of the air, slowly filling a reservoir bottle.

The application, however, is a lot more complicated. Basically, condensation occurs when you cool air to its saturation point. Fontus has a small internal cooler that is divided into two halves.

A solar panel provides energy to cool the upper half of the condenser, a process that heats the lower half. When air flows past the heated lower half, it makes the top cool even further.

Air moving through the chambers is slowed and cooled to condense moisture, which drips down into the bottle.

Under the right conditions, Retezár claims Fontus can collect 16 oz of water an hour. Any PET 16 oz bottle will fit Fontus. Until we can independently verify his claims in a real-world test we’re skeptical of this product, but darned if it wouldn’t be awesome.

Retezár has lofty goals in mind. Keenly aware of a growing worldwide water crisis, he wants to provide an option for those living in water-stressed regions and are often traveled by bike.

We’re not quite sure how air pollution would affect the system, but Retezár shared that “the water is completely safe to drink provided that there aren’t any chemically bound toxics in the surrounding air.”

Not a bad idea, and one that’s up for a James Dyson Award. It’s not on the market yet and is still going through development, but keep your eyes open for this bottle that fills itself in the future.