The installation of a Power-Pipe® Drain Water Heat Recovery (DWHR) System in multi-unit residential buildings is a proven, practical and affordable way to reduce building water heating costs by 20 to 40%.

The Power-Pipe is simple to specify and easy to install on building drain stacks. It is the only heat exchanger that efficiently allows for up to four apartment or condominium units to be plumbed on a single System, without a discernible water pressure loss.

The Power-Pipe Systems typically used for multi-unit residential buildings are C-type (commercial series) units. These feature connections of 1 inch for the cold water side in comparison to ¾ inch connections for R-type (residential series) units, allowing a greater capacity.

The Power-Pipe can be installed in three configurations. The optimum installation for energy savings is to route preheated water from the Power-Pipe to both the water heater and the cold side of the shower (known as an "equal flow" configuration). In this configuration, up to two apartments can be served by a single Power-Pipe® System.

The Power-Pipe may also be installed to feed preheated water to either the water heater or the cold water side of the shower (known as "non-equal flow" configurations). Either of these configurations will de-rate the efficiency of the system by some 25%. However, up to four apartments can be served by one Power-Pipe System in these configurations, which makes the application very profitable.

For multi-unit residential buildings with a central water heater, the preferred configuration is to send preheated water from the Power-Pipe to the shower cold water line. This prevents "wasting" energy by distributing the preheated cold water line through several Power-Pipe plumbed in parallel when heat is being recovered from only one drain pipe.

Although configuring the Power-Pipe to deliver preheated water only to the cold water line de-rates the system''s efficiency by some 25%, the lower efficiency is easily offset by the fact that, in this configuration, one Power-Pipe unit can feed up to four apartments.

Installation Overview

Important notes:

Drain Pipe

  1. Determine diameter of the existing drain pipe. The Power-Pipe''s diameter must be equal to that of the existing drain pipe.
  2.  Support the vertical drain pipe properly before cutting and removing a section.
  3.  Measure, cut, remove and replace the vertical section of the existing drain pipe with the Power-Pipe. Be careful to leave sufficient clearance for connections and fittings.

Water Pipe

  1. Install appropriate plumbing fittings on both ends of Power-Pipe for connection to cold water supply.
  2. Turn off cold water supply and drain the line.
  3. Connect incoming cold water to the bottom port of the Power-Pipe coil.
  4. Connect the outgoing cold water supply to the top port of the Power-Pipe coil.
  5. Determine appropriate placement and installation of shut-off, drain or bypass valves and clean-out traps, based on applicable state and local codes.