The eva2o concept from designer Dennis Cheng is quite a simple idea, that aims to keep fruits and vegetables fresh longer without employing energy consuming devices. The basic idea is quite simple and age old, employing water evaporation to cool contents, quite like in earthenware. The designer says that in the UK, a third of grocery store food is purchased and wasted, and nearly 60% of that could be avoided. A similar story could be repeated for many other countries of the world, and that avoidable 60% is what the eva2o aims to save.
It is a countertop unit with a double-walled earthenware body and a rotating glass lid sits at the top. Water can be poured between the walls of the earthenware, and as moisture escapes through the walls, it steals heat from the unit, providing natural cooling to the edibles stored inside. Geometry of the unit ensures good air circulation and lowered temperatures without the need of an external power supply.