The heat pipes used in our solar collectors have a boiling point of only 250°C . So when the heat pipe is heated above 250°C (86oF) the water vaporizes. This vapour rapidly rises to the top of the heat pipe transferring heat. As the heat is lost at the condenser (top), the va pour condenses to form a liquid (water) and returns to the bottom of the heat pipe to once again repeat the process.

Each heat pipe is tested for heat transfer performance and exposed to 250oC (482oF) temperatures prior to being approved for use. For this reason the copper heat pipes are relatively soft. Heat pipes that are very stiff have not been exposed to such stringent quality testing. Given this strict quality control and high copper purity, the life expectancy of the heat pipe is even longer than that of the solar tube.