How does the ThermoDrain work?
The Residential Drain Water Heat Recovery (DWHR) system
The ThermoDrain 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 ThermoDrain heat exchanger works under the principle of gravity film exchange. Due to the superficial tension present in liquids, the waste water 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.
Flash media provided by Gas Metro Energy Efficiency Fund A Green Technology
When you save energy, you save money and lessen your impact on the environment. For every ThermoDrain unit installed, you are making the earth greener by reducing your green house gas emissions by 1 ton per year per household.
Using a ThermoDrain, the incoming water to the heater has been preheated thereby reducing thermal stress on your tank and increasing its life expectancy.
You will also triple your hot water tank capacity by three fold. This means that a 180 Liter (40 Gallon) tank when combined with an ThermoDrain will give you the equivalent usage of a 540 Liter tank (120 gallons). No more cold showers!
A general information brochure is available in PDF format
- ThermoDrain Flyer (0.5 MB)
- ThermoDrain Data Sheet (0.3 MB)
