How the Power-Pipe works

How it works

Water falling down a vertical drain stack does not run down the middle of the stack, but instead clings to the inside wall of the pipe. In a Drain Water Heat Recovery (DWHR) application, falling drain water forms a thin film that rapidly imparts its heat to the colder pipe wall. The Power-Pipe® captures much of this heat, then "recycles" it to raise the temperature of incoming cold water.

A 60-inch Power-Pipe System, for example, can raise the cold water temperature from 10°C (50°F) to as much as 24°C (75°F), under equal flow conditions.

Because the incoming cold water is preheated before going into the water heater and plumbing fixtures, the water heater uses less energy to raise the temperature of the water to the desired level for use, which saves money and increases the effective water heater capacity.

All Power-Pipe DWHR units are performance tested according to the CSA B55.1 testing protocol and safety tested through UL and the CSA B55.2 standard.

Drain Water Heat Recovery (DWHR) Crash Course

In residential or multi-residential applications, when warm water goes down your drain from showering, a faucet, or washing appliances, it carries away valuable energy with it. The same applies for commercial or industrial applications, for any heated water processes which carry away valuable energy as they run down a drain.

Drain Water Heat Recovery is the process of recovering part of this valuable energy from the warm water, and using it to preheat your incoming cold fresh water. This process can be used for your home, apartment, condo, business or many industrial processes using heated water.

With an innovative and proven DWHR system such as the Power-Pipe, there are no moving parts. DWHR is already in use around the world, providing affordable, long-lasting savings.

The Science Behind Falling Film Heat Exchangers

Water flows rapidly down a vertical drain pipe. It is a common misconception that there is not enough time for the heat transfer to occur between the warm liquid and the wall of the inner pipe. The fact is that heat transfer is not highly dependent upon resident time but is far more dependent upon intimate contact between the fluid and the wall. Drain water flowing quickly becomes a very thin turbulent film of about a millimeter in thickness. As a result, it imparts its heat to the pipe wall very readily.

In the case of the patented Power-Pipe® DWHR, a series of formed copper coils are tightly wrapped around a specific length of copper drain pipe at our manufacturing facility.

This process forms what is commonly known as a double wall heat exchanger. The double copper wall design protects incoming fresh water carried in the coils from being contaminated by the drain water.