STREAM COOLER is a non-electric cooling device activated by natural water flow. It is applied heat transfer theory: the quantity and velocity of water flow amplify the cooling effect. Its special funnel, which has airfoil cross section, accelerates the velocity of the water flow to cool the chamber (by Bernoulli's theorem and principle of continuity). Once the water is drawn through the structure, the velocity is rapidly increased, and it draws surrounded water to container. The process is eight times faster than cooling without it. In outdoor activities like camping, you can easily install it in a river / stream to cool down food and drinks.