New Heat Pump Water Heater
Richard Tuttle (right) of Carteret-Craven Electric Cooperative, along with co-op member Joy Williams, looks over her heat pump water heater. Notice the compressor/evaporator unit atop the water tank.
Joy Williams and family have cut their electric bill in half since they moved from a drafty apartment into a 1,200-square-foot Energy Star home, with a piece of their energy savings attributed to their highly efficient heat pump water heater.
Their house, built by Crystal Coast Habitat for Humanity in October 2010, is equipped with a General Electric Hybrid Water Heater that Carteret-Craven Electric Cooperative donated. CCEC marketing specialist Richard Tuttle routinely reads the separate meter installed on the unit when it was put in place.
"We didn't know how well it would do going into the project," he said. "We were looking to validate the manufacturer's performance information. We have actually seen it outperform the manufacturer's estimated energy efficiency."
The unit, which is in a hallway closet, makes a low humming noise when it's running, but with the louvered doors closed, the sound is barely noticeable. The thermostat is set at 120 degrees, and the unit is set to "hybrid" mode.
"It's wonderful," said Mrs. Williams, who only has to remember to keep the filter clean. And since the unit is next to the washer and dryer, remembering to do that is easy.
Not only has the energy-efficient home helped cut expenses, Mrs. Williams said, she and her three children have become much more energy-conscious, turning out lights and electronics when they leave a room and limiting time in the shower. Light fixtures are all fitted with CFLs, and the house has a sealed crawlspace.
Cutting in half an electric bill that once ran about $200 a month puts a lot of extra money back into a household that is used to operating on a tight budget.
While the tank section of the unit is not much different than a traditional water heater, what's different about the hybrid unit is that it has a compressor and evaporator integrated into the top of the unit to draw ambient heat in from the surrounding space using two variable speed fans. Coils wrap the internal tank all the way to the bottom and transfer this heat into the tank, heating the water.
The water heater has five distinct operating modes, but except for a brief period during CCEC's testing phase, the unit at the Williams' home is best suited for hybrid mode because of the number of people in the household.
Water heater settings
"E-heat": In this mode, the water heater will only operate the heat pump to recover the water temperature. This is the most efficient mode, as the traditional electric heating elements are never used.
Hybrid: In hybrid setting, the unit will use the heat pump first and foremost as its main way to heat the water. If and when a faster recovery time of the water temperature is needed, the internal elements will alternate to provide a quick temperature recovery. When the system determines its demand need has been met, it will automatically revert back to using the heat pump.
High Demand: This is a great feature to use if you have additional people staying at your house for a weekend. This mode operates very similar to hybrid mode; however you are letting the system know in advance that it will be experiencing a larger water demand than usual. The water heater will be faster to react to temperature recovery by cycling on the heating elements sooner and longer.
Standard: In this mode, the heat pump will be shut off and the system will work exactly like a standard water heater, using only the electric elements to heat water.
Another feature Mrs. Williams likes is the ability to shut off the unit with the push of the "vacation mode" button if the family is going to be away from home for a time.
Additionally, it has an error code display that will let the homeowner know if the unit fails for any reason. "All the homeowner has to do is call a 1-800 number for help," Tuttle said.
While a heat pump water heater is more costly to purchase than traditional units, tax credits and other incentives, such as CCEC's rebate program, can make the investment worthwhile.
For more information about heat pump water heaters, visit www.energysavers.gov. To look at units, visit a home improvement or plumbing supply store. You can also ask a plumber who has experience installing them.