Upgrade to a drain-water heat recovery system

Why? Showering is one of the leading ways we use water in the home, accounting for nearly 17% of residential indoor water use. When hot water goes down the drain, the energy you paid to heat that water leaves with it. A drain-water heat recovery (DWHR) system recycles this heat to reduce your energy use. Consider installing DWHR when you remodel your home.
For large families: Frequent showers demand a lot from your water heater. DWHR increases your water heater's capacity so that back-to-back hot showers are not a problem. In fact, homes with high hot water use save the most with DWHR.

How it works: In most cases, a small copper pipe is coiled around the home's main drainpipe. When hot water drains, it transfers heat through the spiraling pipe to fresh water traveling into the home (don't worry—the clean and dirty water never mix). The drain water preheats the new water so your water heater needs less energy to supply sinks and showers.

Good to know: DWHR can be installed on an existing home for the same energy savings, but at a higher installation cost.

Things to think about:
  • DWHR is compatible with storage, tankless (demand) and solar water heaters.
  • Although many plumbing and heating contractors may be new to DWHR since it is an emerging technology, the installation is straightforward and uses commonplace tools. It should take your plumber one to two hours to install.

Popularity in your area Help

268 people do this

Tip Details