How Hybrid Water Heaters Will Work

A solar water heating system
Hybrid water heaters could save the average family hundreds -- possibly even thousands -- in energy costs each year.
iStockphoto/Georgios Alexandris

­Unless you've had the unfortunate incidence of a broken water heater, you probably haven't given much thought to that large structure in the closet or basement. Until it stops working and you're stuck with cold showers, water heaters don't occupy most people's daily thoughts.

In fact, until recently, water heaters weren't even on the radar of Energy Star, a government program that certifies energy-efficient appliances. Even though water heaters generally use the most energy of any home appliance, Energy Star didn't start regulating their energy usage until 2008 [source: Green].


Now there's a movement to make water heaters more energy efficient. This can mean huge energy savings, as about 17 percent of a home's energy usage stems from its water heater [source: Green]. These savings are good not only for the environment and your future, but also your wallet. It's estimated that hybrid water heaters could save the average family hundreds -- possibly even thousands -- in energy costs each year.

­Sound like a dream? Well, on one hand, it is. There are only a few hybrid water heaters on the market, but there are several more in the pipeline for the next couple of years. And hybrid heaters are more expensive than your average water heater  - about $2,000 to $3,000 a pop for the ones on the market righ­t now. This article will help you get a jump on the latest developments in hybrid water heater technology, so when a model that meets your needs hits the stores, you'll be ready to buy.

When you hear the word "hybrid," you might imagine a tank that gets charged with a battery and then can also run off gas, like a hybrid car. Read on to discover the technology behind hybrid water heaters and find out if your imagination is correct.


Hybrid Water Heater Technology

Basically, hybrid water heaters combine the technology of tank and tankless conventional hot water heaters.

Traditional tank heaters heat from the bottom, with the air rising through the tank and exiting from the top, allowing a fair amount of heat to be wasted. Tankless models also heat from the bottom, but the water flows through copper pipes. However, tankless models have been criticized because they don't store water and continually provide hot water to multiple places in your home.


The technology behind new hybrid water heaters varies by the model. Eternal Hybrid, one of the few currently out on the market, uses multiple passes of the heat and water to warm up more efficiently. The machine has 44 pipes that heat up, and the water flows around them for quick heating [source: Eternal Water Heater]. And, unlike a tankless system, the hybrid heater contains a reservoir to hold some water at all times, so you never run out of hot water.

This isn't the only technology that hybrid water heaters can use. General Electric is planning a hybrid electric water heater to hit the market at the end of 2009 -- it uses hybrid technology to absorb heat within the air and then transfer it to the water [source: GE]. Hybrid WaterHeater Incorporated is developing a heater for 2011 that will amalgamate several technologies, including fuel cells, batteries and super capacitors [source: Hybrid WaterHeater Inc].

To discover the benefits of a hybrid water heater over what you're using now, read on.


Benefits of Hybrid Water Heaters

The most obvious benefit of hybrid water heaters is their efficiency. Water heaters can be extremely energy inefficient, in part because their energy usage wasn't regulated until 2008 [source: Green]. This is particularly concerning because they often use the most energy in a home -- almost one-fifth of your entire energy use!

Because these models are more energy efficient, the consumer will save money. But what are the specific benefits of all these models?


  • Eternal Hybrid boasts an 98 percent efficiency rate [source: Eternal Water Heater]. A.O. Smith has a hybrid model, the Vertex Power-Vent Gas Water heater, which operates at 90 percent efficiency [source: A.O. Smith]. GE's model, meanwhile, should be 50 percent more efficient than its current models [source: GE].
  • GE's savings should amount to about $250 per year for an average family. Hybrid WaterHeater Inc. boasts that its potential energy savings would be up to $2,160 per year [source: Hybrid WaterHeater Inc]. Unfortunately, you'll have to wait until 2011 to test that one out.
  • If you're looking for easy installation, GE's and A.O. Smith's models will match the standard tank designs that fill most homes. Or, if you're looking to save space, the Eternal Water Heater is about half the size.

Eternal's model also has almost zero greenhouse gas emissions [source: Eternal Water Heater]. This means it is one of the cleanest burning of all household appliances -- not just water heaters -- out there.­

Whether your water heater needs to be replaced or if you just want to be greener -- both in your house and in your wallet -- consider replacing your water heater with a hybrid water heater. Don't worry about running out today and getting one, though, as few are currently on the market. Wait a few years and you should have a multitude of options.

For more information, visit the links on the next page.


Hybrid Water Heaters - Lots More Information

Related HowStuffWorks Articles


  • A-1 Plumbing and Emergency Rooter. "Hybrid Water Heaters - The Best of Both Worlds for Your Hot Water." (Accessed 3/1/09)
  • A.O. Smith. "Vertex Power-Vent Gas Water Heaters." (Accessed 3/1/09)
  • Energy Star. "Energy Star." (Accessed 3/1/09)
  • Eternal Hybrid. "Technology / What is Eternal Hybrid." (Accessed 3/1/09)
  • Forster, Lyndsey. "Eternal Hybrid Water Heating System Evolutionizing the Water Heater World." Ebuild. September 2007. (Accessed 3/1/09)
  • GE. "Energy Efficient Products." (Accessed 3/1/09)
  • Green, Hank. "GE's New Water Heater Could Kill 30 Coal Plants." Eco Geek. April 2, 2008. (Accessed 3/1/09)
  • Hot Water Facts. "Water Heater Basics: Hybrid." (Accessed 3/1/09)
  • Hybrid WaterHeater Inc. "Product." (Accessed 3/1/09)
  • TIAX. "Hybrid Water Heater." (Accessed 3/1/09)