As the cost of utilities continues to rise, many homeowners are looking for ways to save on energy bills. We asked Roch Naleway, the market development manager for utilities at A.O. Smith, to explain what a heat pump water heater is and why it offers energy efficiency and cost savings to homeowners. He collaborates with utilities, distributors and contractors to foster the adoption of efficient and grid-connected water heaters.  

What is a heat pump water heater?
A heat pump uses electricity to take away heat from the ambient air and move it into the tank to heat the water. The technology is similar to a refrigerator, except that a refrigerator moves heat from inside the unit to the outside. A standard heat pump water heater features a 50-gallon storage tank, but larger tanks are also available. Standard models require a 240-volt, 30-amp circuit. 

What are the benefits of a heat pump water heater? 

Energy savings. Heat pump water heaters use 75% less electricity than traditional water heaters, also called electric-resistant water heaters. So with these water heaters, your carbon emissions are much lower.  

Cost savings. Reducing your energy use means lower energy bills. Because many utilities charge lower rates at certain times of day, you can save more money by heating your water during those off-peak hours and storing it until you’re ready to use it.  Most homeowners can expect $300-$800 per year in energy savings when they switch to a heat pump water heater. With the significant reduction in energy bills and available incentives, a heat pump water heater can pay for itself in just two or three years. 

What makes a heat pump water heater so efficient?
Conventional water heaters create “new” heat using electricity or gas to heat water. A heat pump water heater extracts existing heat from the air around the unit and transfers it to the water. Essentially, you are simply moving heat from one space to another rather than generating heat, thus drastically reducing energy usage.  

What should a homeowner consider when selecting a heat pump water heater?
One of the most important factors is sizing the heat pump water heater correctly. You want to consider the number of bedrooms, bathrooms, faucets and major hot water applications such as a soaking tub that you have in your home. The number of people that you have in your home may fluctuate, but you never want to run out of hot water. Major manufacturers have sizing tools available on their website to help determine the size you need.  

Features are similar between brands, but some models feature leak detection, which sounds an alarm or notifies you on your phone if water is detected in the drain pan. Some models will automatically shut off the system when the alarm is triggered, which may be useful to some homeowners. 

How easy is installation?
Installation of a heat pump water heater is similar to installing a standard water heater, but there are a couple of differences. The process of moving ambient heat from the space around the water heater into the water tank results in condensation buildup. You’ll need to install a drainage tube that can be routed either to a basement drain or sink, or to the exterior of the home.  

Location is also important. You’ll need to install the heat pump water heater in a space with plenty of air to draw heat from. Depending on your hot water needs, the space around the unit should be about 450-700 cubic feet. As the water heater pulls heat from this space, the ambient temperature naturally drops. If it drops lower than 37 degrees, most heat pump water heater will shift into electric-resistance mode and will not be as efficient.  

If you don’t have this much space for your heat pump water heater, you can install it in a closet?— just be sure to also install a louvered door on the closet to allow for circulation. An Energy Trust trade ally contractor can help ensure your heat pump water heater is installed in the best location in your home and with the best ventilation and accessibility to ambient air.   

What maintenance is required?
Regardless of whether you have a heat pump water heater, gas tank water heater or an electric-resistance water heater, you should flush a few gallons from the bottom of the tank once per year. You also need to replace the sacrificial anode, which is a metal rod in the tank that helps oxidize metals in your water, every three to five years. If you don’t replace this, it could lead to rusting in the tank. 

Along with that maintenance, a heat pump water heater has a filter on top that needs to be washed annually. If the space is particularly dirty, such as in a workshop with excess sawdust or a laundry room with stray lint from a dryer, you may need to clean the filter more frequently.  

What incentives are available for heat pump water heaters? 
Energy Trust offers discounts on heat pump water heaters to eligible customers. You can also find a trade ally to help you install the water heater once you get it.