The Technology behind the Chilly Tube
Before refrigeration and air conditioners, man used water to keep his precious items cool. In ancient Egypt they used pots or vases made from unglazed clay to keep items like beverages cool by putting the containers into pits dug into their floors. This allowed some of the water content to slowly evaporate into the surrounding soil keeping the contents of the pots cool.
Evaporative cooling is a physical phenomenon in which evaporation of a liquid into the surrounding air, cools an object or a liquid in contact with it. Latent heat, or the amount of heat that is needed to evaporate the liquid, is drawn from the air or the object that it is in contact with. This principal is what the ancient Egyptians used to keep their water cool and the pioneers used to keep milk, butter and meat cool. For pioneers the problem of keeping butter from going rancid in hot weather was solved by putting it in a basin covered with a flannel cloth. The basin was then put into another shallow pan of water so that the ends of the flannel dipped into the water slowly wicking up the moisture. The evaporation of the water kept the basin cool and hence also the butter. Even the cowboy’s used this principal by wetting their bandanas and wearing them around their necks. This helped them stay cool as long as they were near a source of water and could keep soaking the bandanas as they dried out.
In the early 1990’s, Farmers needed a solution to keep their crops alive during short drought seasons. Engineers developed the polymer granules that you find today in your Chilly Tube. These crystals were specially formulated to absorb water when there is an abundance, like during the spring rains, and then to release it during the summer heat and drought.
The modern day Chilly Tube works the same way. It absorbs large amounts of water when you soak it, the outer cloth quickly dries, but the water will continue to slowly evaporate, drawing the heat necessary for evaporation to take place from you, thereby keeping you cool! The crystals are the solution that allows the Chilly Tube to hold more water than if you were to soak a wet drippy bandana that dries quickly in the summer's heat, so you can stay cool, neat and comfortable all day!