Andrew Wagner and Steven Price, engineers at Naval Surface Center Dahlgren Division, are the recipients of a patent awarded by the U.S. Patent and Trademark Office for the capillary heat exchanger. The device allows for efficient transfer of heat between two sources of liquid or gas.
When asked about the development behind this invention, Wagner described an interesting source of inspiration. Working as a teenage lifeguard for an indoor pool at the YWCA in Windsor, N.Y., he would often get headaches due to the chlorine in the air. Although he could crack doors and windows to bring in some fresh air, patrons would often complain about the cooler temperature. So, I started thinking of a way to exchange the indoor air with the outdoor air without losing the warmth, said Wagner.
Another source of inspiration is a biological anecdote of a surprising nature heard by Wagner. The topic? How ducks avoid hypothermia while swimming in freezing temperatures. This is achieved via a mechanism known as a countercurrent exchange, which is the principle mechanic in the invention.
As explained by Wagner: Arterial blood traveling to the ducks feet is cooled by passing an overlapping network of returning veins. By the time the blood reaches the feet, it is at the same temperature as the water. This prevents the loss of body heat. Likewise, the returning venous blood is warmed by arterial blood moving away from the body. By the time the blood circulates back towards the body, it has been warmed, preventing hypothermia. I thought, why cant this same principle be used with air?