Bellows Plumbing, Heating & Sewer

Heat Pump Water Heaters vs. Standard Electric

Wednesday 7/28/10

There are a lot of options when choosing a new water heater: tankless, HE tankless, standard tank water heater, electric heat pump, boiler, standard electric water heater, and more.  Choosing a water heater is a major investment. Most clients only see the $1000 to $4000, depending on the system they are purchasing,  they spend on the day of purchase. However, a standard electric water heater installed in the typical American can cost approximately $15,000 over its 13 year life! ck

Heat pump water heaters, also referred to as HP water heaters, are one of several energy efficient water heaters that can offer big savings. HP water heaters can be up to three or four times more efficient than a standard electric water heater when sized and property installed.

To better understand how a heat pump water heater works think of an air conditioner. Place the air conditioner’s outdoor coil, the part that blows hot air, inside a water heater storage tank and you essentially have a heat pump water heater.  A heat pump water heater works by extracting heat from the air around the water heater and transferring it to the water. This is done by passing refrigerant through a compressor, expansion valve, and evaporator coil. All items you’ll find on a standard air conditioner or heat pump.

A standard electric water heater uses elements inserted in the tank to heat water. The heat is generated by applying electrical current and creating resistance. The downside to creating heat with this method is that it requires a tremendous amount of energy. A heat pump water heater uses electricity to power the heat pump’s compressor however heat is being drawn from outside the tank in the surrounding air and transferred to the water inside the tank, making for a more efficient system. Most HP water heaters also have electrical elements as backup in the event that the water heater cannot keep up with demand or the outside air temperature falls below 40 degrees Fahrenheit. At 40 degrees Fahrenheit and below most heat pumps are not able to extract sufficient heat from the surrounding air.

So what does all of this mean for the homeowner? In two words, Energy Savings. A standard electric water heater has an energy efficiency rating of .93 while a heat pump water heater has an energy efficiency rating of 2.2. Given the following variable, which are very modest, the average household would experience a savings of nearly $4000 over the 13 year life of the water heater.  

Variables
Cost per kilowatt hour: $.11
Time period: 13 years & 18 years
Increase in energy prices over time period: 10% (extremely modest)
Gallons of hot water per person: 35
Persons in house: 4
Rebates: $0 (thru 2010 $1500 in rebates are available on heat pump water heaters. We did not account for this in our calculation so true savings should be more than stated below.)
Ground water temperature: 55 F

13 year time period

18 year time period

The primary manufactures of heat pump water heaters are GE, Rheem, and AO Smith. All three of these manufactures make a great product. All qualify for up to $1500 in tax credits under the American Recovery Act of 2010. What separates them from each other are additional features and price. Last we checked Rheem came in at the lowest price and GE came in with the most features. Consult with your local plumber to find the right water heater for you or give Bellows Plumbing, Heating, A/C, and Sewer a call 408-866-4620 / 831-477-7150

Note: This same cost analysis can be performed on tankless natural gas and propane water heaters. Please call for an water heater savings analysis and comparison.  831-477-7150 / 408-866-4620

Posted: by Jason S
Tags: Water heaters, Tax credits, Heat Pump, Air Conditioner