ETC Tube

An evacuated-tube collector contains several rows of glass tubes connected to a header pipe. Each tube has the air removed from it (evacuated) to eliminate heat loss through convection and conduction. Inside the glass tube, a flat or curved aluminium or copper fin is attached to a metal pipe. The fin is covered with a selective coating that transfers heat to the fluid that is circulating through the pipe.

There are two main types of evacuated tube collectors :

• Direct-flow evacuated-tube collectors.