How the ECO-GFX works

The Heat Exchanger

The ECO-GFX heat recovery unit is composed of a copper drain section around which a copper pipe is molded and wound. As hot water drains down the central copper pipe, an important heat transfer occurs thereby preheating the cold water circulating in the outer coil. This incoming cold water may be preheated by more than 18 degrees Celsius (32 degrees F) before entering the water heater.

The physics

The ECO-GFX heat exchanger works under the principle of Gravity Film eXchange (GFX). Due to the superficial tension present in liquids, the wastewater clings in a film-like fashion to the inside wall of the drain pipe as it undergoes gravity flow in the open drain. This greatly improves the effectiveness of heat transfer from the falling drain water to the water inside the copper coils that winds around the central pipe. The heat exchange is thus completed with no contamination risk to the incoming cold water.

A superficial film forms on the interior wall of the ECO-GFX as hot waste water transfers its heat energy to the copper drain tube.