Useful when describing differences in solar pool heater collector design to prospective customers, this sales sheet compares cross section graphics for \"square tube-on-tube\" (Techno Solis), \"round tube-on-tube\" (FAFCO, \"loose tube\" (Heliocol) with the Ecosun \"vented tube-and-web\" design.
<br><br>
The piece also raises potential disadvantages of each particular design, culminating in a \"lessons learned\" with Ecosun.