How a Hybrid Water Heater Works

By: Sarah Siddons  | 
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

A hybrid water heater is a feat of engineering efficiency that few homeowners know all that much about. Realistically, most of us only ever think about our water heaters when the when the taps run cold. Even then, most homes are outfitted with tank or tankless water heaters.

Ignoring out water heaters is so common that in fact, water heaters were one of the more recent household appliances recognized by Energy Star, the government program that certifies the energy-efficiency of 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].


It's crazy to think about, when you consider that a water heater can account for as much as 17 percent of a home's total energy usage [source: Green]. If you want to make your home more energy efficient, look to your water heater. And, when it comes to energy efficiency, things don't get better than hybrid hot water heaters.

Storage Tank Water Heater

The traditional method for providing hot water to a home are often called storage tank water heaters. They're popular because they're among the most affordable options available.

Storage tank water heaters can store as much as 50 gallons of hot water at a time, making them a great option for those who use a lot of hot water at any one time. There are drawbacks [source: Consumer Reports].


These water heaters require a decent amount of floor space, and are far from the most efficient option. After all, when you store 50 gallons of hot water, you create a lot of excess heat that escapes and is inevitably wasted. As affordable as they are up front, storage tank water heaters do cost more money in the long run.

Tankless Water Heaters

These models are ideal for homes without a lot of floor space or prefer efficiency. Instead of storing hot water in a large tank, tankless water heaters use electricity or natural gas to heat water as you need it. Tankless models also heat from the bottom, but the water flows through copper pipes.

While significantly more efficient than their storage tank counterparts, tankless models have been criticized for their inability to provide a lot of water to multiple destinations in your home at any one time. They do prevent the use of a lot of energy though. And these savings are good not only for the environment and your future, but also your wallet.


Hybrid Heat Pump Technology

Hybrid water heaters take energy efficiency to an entirely new level. They aren't nearly as popular as the other styles mentioned, but that's expected to change soon.

A hybrid water heater combines key elements of both tank and tankless water heaters. They use a storage tank, and are bowered by electricity, but instead of heating the water directly they draw on heat from the surrounding air and heat the stored water using heat pumps.


The technology behind hybrid electric water heaters varies by the model, but the benefits are fairly uniform. It's a best of both world scenario that offers a large supply of heated water as well as industry-leading energy savings.

There are drawbacks too. Hybrid heat pump water heaters pull warmth from their environment, which means they must be installed in a climate-controlled and spacious environment. They simply can't operate in a cold space [source: U.S. Department of Energy]. They also require routine maintenance and proper care to ensure maximum efficiency.


A Greener Home

Our quest to reduce our collective carbon footprints and reduce our reliance on raising energy costs has seen to the invention of a number of impressive household appliances. The heat pump water heater is no exception.

This innovative hot water solution delivers impressive results in homes all over the world. And, when you consider that a large portion of a household's energy bill is attributed to heating water, that's no small feat.


There's no telling what the future of household efficiency will look like but, if heat pump water heaters are any indication, we can say that things are indeed the path to a greener future.

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?


  • 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.
  • 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.

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 below.


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)
  • 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)