Save Money and Energy with Drain Water Heat Recovery Systems

Stacy Sare Cohen
Written by Stacy Sare Cohen
Updated December 16, 2021
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Highlights

  • Drain water heat recovery systems cost between $300 and $500

  • Homeowners can get their money back in energy savings in as little as 2.5 years

  • A drain water heat recovery system reduces the energy consumption of your water heater by up to 25%

  • The system requires no maintenance and contains no parts

  • Most drain water heat recovery systems have a lifespan of 30 years

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Want to conserve energy? Look no further than a drain water recovery system. These systems tackle one of the biggest energy wasters in your home: heating hot water. Every time you shower or run the dishwasher, you fritter away hot water. A drain water heating recovery system, also known as a drain line heat exchanger, recovers the water and reheats it to save you money and reduce waste. Here’s what you need to know about drain water recovery systems.    

What Is a Drain Water Heat Recovery System?

A drain water heat recovery system consists of two copper pipes and a coil. The pipes transfer the existing heat in your drain water to the new clean water as it passes through a second pipe before it reaches your water heater.

How Do Drain Water Heat Recovery Systems Work?

The heat exchanger is essentially two short sections of pipe fused against each other. Though the pipes are fused, the water never mixes. Warm wastewater flows through the larger drain line. The smaller section circulates clean water near the drain line, sometimes winding around it, which forces heat to transfer from the dirty water to the clean.

Rather than flowing into your sewer system or septic tank, the hot water is recycles and used to preheat the new clean, cold water on its way to your water heater. 

You’ll gain the most savings when used with simultaneous water flows such as showers, but systems with additional storage capacity can store water for later use in appliances such as washing machines and dishwashers. The system's exact size will depend on your household hot water needs. Three to four feet of vertical drain stack is usually enough to reduce your hot water energy consumption by up to 25%

Benefits of Drain Water Heat Recovery Systems

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The technology used in drain water heat recovery systems minimizes energy consumption. It also lowers your energy bills and prolongs the life of your water heater. Even better, these systems are compatible with all different water heating systems, including tank water heaters and on-demand models.

Greater Energy Savings

A drain water heat recovery system can reduce the energy consumption of your water heater by up to 25%. Less energy consumption also means you’ll pay less for your energy bills every month with savings beginning in as little as a year for large households.

Extends the Lifespan of Your Water Heater

It’s quite simple. Pre-heating cold water on its way to your water heater takes less time and energy to produce the temperatures needed to use your shower, dishwasher, and washing machine. The less wear-and-tear your water heater endures, the longer it will last.

Compatible With Any Water Heater

Drain water heat recovery systems work with a variety of water heating systems, including demand, electric, gas, solar, and tankless water heaters. This makes heat exchangers compatible with any water heater you choose to install in your home.

Require Little to No Maintenance

Drain water heat recovery systems are truly a one-and-done add-on because their copper pipes can last for decades, and they don’t contain any parts that need repairing or replacing. Heat exchangers have been known to last over 30 years. Once a local plumber installs it, you can enjoy its energy and money-saving benefits without needing to lift a finger to maintain it.

Cost to Install a Drain Water Heat Recovery System

 The price you’ll pay for drain water heat recovery systems ranges from $300 to $500, depending on the installer’s labor rate and the region where you live. A family of four taking up to eight daily showers can recoup the savings in as little as one year. The more you use the system the more money you’ll save. A reputable, local plumber can install the system correctly in about two hours

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