Between 1/4 and 1/3 of the energy consumed in the average home is used to heat water for everyday household tasks. 90% of that energy runs down the drain, mostly in the shower. This is easy to see for yourself -- when somebody is taking a shower, simply touch the drain pipe. It will feel warm. And all that warm water and energy are flowing into the sewer.
A simple solution
The "Power-Pipe" is a Drain Water Heat Recovery system. The concept is simple -- wrap the cold water pipe around the drain pipe. The cold water pipe picks up some of the heat flowing down the drain pipe, pre-heating this cold water a little bit, so that the hot water tank has less work to do. There is nothing to plug in and there are no moving parts.
The incoming potable water and the waste water are separated by two layers of copper tubing to ensure that the fresh water and waste water do not mix.
Watch the following video to learn how the Power-Pipe works.
Planning and Installation
The Power-Pipe needs to be installed vertically in place of a drain pipe, and needs to tie into the water supply of the house. The technology is effective during a shower, so the selected drain pipe must drain at least one shower.
In our house, we worked with the plumber to plan the drainage such that both of our upstairs bathrooms (with showers and tubs) would drain through the same "stack" in the basement utility area. As you can see in the below photo, the cold water supply to the hot water tank first passes through the Power-Pipe for a potential pre-heating effect.
There will be absolutely no more concerns about running out of hot water, even with both showers in use!
Where to buy your Power-Pipe
These seem to be very popular in Canada -- even sold in Home Depot and Sears -- but less so in the USA. Fortunately, Energy Federation Incorporated carries them. (Yet another benefit of an Energy Star consultant with an extensive contact network.)
The cost of the 3 inch diameter, 60 inch height Power-Pipe from EFI was $524.85 plus tax. Our plumber is charging $300.00 for the installation. There is also a rebate of $100.00 through Focus on Energy. Therefore, our grand total for the unit and the installation is around $750.00.
It's an easy retrofit, assuming you have a vertical section of pipe that drains at least one shower.