How does drain water heat recovery work? What can it do for you?

Drain water heat recovery


The ThermoDrain’s simple design consists of a single 3/4″ copper potable water tube wound around a central copper drain tube.

The ThermoDrain, drain water heat recovery unit replaces a section of your vertical drain stack. (Lengths vary from 12″ to 100″, 42″ is the most common length)

Wastewater (from your shower or other sources of wasted heated water) flowing down the drain transfers heat to the inner drain tube of the ThermoDrain. At the same time, cold water is flowing in the outer coil, trying to cool down the warm drain pipe. A heat exchange takes place. The cold water in the coil extracts the heat energy from the drain pipe.

The preheated water in the coil feeds the water heater and/or the cold side of the shower. The water heater uses less energy because it is now receiving preheated water instead of cold water. For tankless hot water heaters, this means a significant increase in the flow of hot water. For tank hot water heaters this means up to 3x more hot water for showering.

In the shower, you are now mixing warm water with hot water and therefore use less hot water in the shower. The overall saving is up to 40% on the cost of heating water.

The single coil design offers a very low pressure drop and high efficiency and zero maintenance.

ThermoDrain is easy to install with its optional crimp style PEX fittings and drain couplings especially designed for the unit.

+ 0 K
Installed ThermoDrains
+ 0 ton
Removed CO2 in Atmosphere/Year
ThermoDrain crimp PEX unit
Up to 40%
Environmentally Responsible Product 100%
1 X
More Hot Water!