What is a Heat Pump Water Heater?
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While heat pumps are often associated with whole-home heating and cooling, they can be used to heat water, too.
In some cases, they operate up to 4x more efficiently than traditional water heaters, which use electric resistance to raise the water temperature.
A heat pump water heater only works in specific conditions, though. Understanding how a heat pump works can help you decide whether one is right for your home.
What Is a Heat Pump?
At its most basic, a heat pump is a mechanism that moves heat from one place to another instead of generating heat to raise the temperature of air or water. Essentially, these units work similarly to a refrigerator, just in the opposite direction. Instead of directing heat out of the condenser in the rear of the case like your refrigerator does, water heater heat pumps direct heat to a condenser that wraps around the tank.
Electricity powers this movement of heat, but this type of heating tends to be more efficient than traditional electric-powered heating elements. This high efficiency transfer of heat often results in lower energy bills.
How do I know if I have a Heat Pump?
To identify if your water heater is a Heat Pump, there are a number of places you can check.
First, look for visible signs that differentiate the heater types: A heat pump will often have a fan on top of the unit that pulls in room air, and exhausts cooler air into the environment that the water heater is installed in. In many cases, a heat pump’s interface will also be more complicated; check for a thermostat that has eco and/or boost modes.
Lastly, check the model number or documentation on hand. A tag or label on the side of the unit should provide a model number, which you can research on the company’s website. Any documentation that came with the unit will also describe what sort of water heater you have.
Water Heater vs Air Conditioner Heat Pump Systems
When talking about heat pumps, there is often a significant crossover between heat pump water heaters and air conditioner heat pumps, but they represent two very different applications of the heat pump technology.
While a heat pump water heater focuses on pulling the heat from the surrounding air to heat your water, air conditioner heat pumps often have to serve a dual function:
- Pulling hot air in during the winter
- Pulling hot air out during the summer
Home heating and cooling units have a reversing valve and residential heat pump water heaters do not. At A.O. Smith, we pride ourselves on high-quality hybrid electric heat pump water heaters, so we will primarily focus on heat pump water heaters.
How a Heat Pump Works in a Water Heater
While a conventional water heater uses gas or electric power to heat the water, a heat pump water heater pulls heat from the air. Some combine a heat pump with electric heating elements to accommodate high water usage. This type of water heater may also be referred to as a hybrid electric water heater.
You can find a heat pump water heater with an integrated tank. A professional plumber can help you install a heat pump water heater in your home.
Other Advanced Heat Pump Systems
Heat pumps incorporate a wide range of technological advances. Some include smart controls that let you adjust the water temperature in the tank using a phone app, and many water heaters include safety features, such as automatic shutoff valves.
Compressors
Compressors are part of the outside-facing unit in a heat pump. Heat pump water heaters often have a compressor built into the top of the appliance.
Hybrid systems for water heaters typically combine heat pumps with electric heating elements rather than gas. A hybrid electric heat pump water heater uses a compressor and electric heating elements to transfer heat to your water.
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Why Choose a Heat Pump Water Heater?
A heat pump water heater generally costs less to run than a conventional water heater, because it uses heat from the air to heat water. The lifespan of a heat pump water heater is typically longer, too. Most units last 10 to 15 years. But the benefits don’t stop there.
You’re Looking for an Environmentally-Friendly Heating Solution
Water heaters that utilize a heat pump are more environmentally friendly than standard water heaters. The reduced energy consumption lowers carbon emissions compared to traditional systems. These units also tend to operate quietly and are rated for 45 Db.
You Have the Right Indoor Climate for Efficiency
Two major concerns when considering a heat pump water heater are placement and climate. A heat pump works most efficiently at higher temperatures surrounding the water heater. Some modern heat pump water heaters are designed to continue operating in colder temperatures, but they might be less efficient during the winter months.
For maximum efficiency, we recommend installing heat pump water heaters in an indoor environment between 37-120 degrees. When you are outside that temperature range, the heating elements will be used to heat the water and you will not have energy savings.
You Have the Space for a Heat Pump Water Heater System
Heat pump water heaters need plenty of space to draw in surrounding air. You need around 450 cubic feet of space for reliable operation. Many homeowners opt to put this type of water heater in a basement or garage. Another option is to use ducting if the installation environment does not provide 450 cubic feet of air. Dehumidification and slight cooling of the installation environment is a natural side effect of a heat pump water heater, so if you don't use a ducted system, you might notice that the air in the room becomes drier.
Some hybrid water heaters use both a heat pump and an electric heating element. The heating element is used to quickly heat water during periods of high demand, while the heat pump warms and maintains the tank water at a pre-set temperature during normal use periods.
Need Help From A Pro?
A. O. Smith water heaters are professionally installed by local independent contractors.
Rebates & Tax Credits
Get up to $2,000 in federal tax credits, plus up to $1,600 in local utility rebates may be in your area when you upgrade to a Smart Heat Pump Water Heater!
ACT NOW - Federal Tax Incentive ends 12/31/2025
When filing a federal tax return, include A. O. Smith's Qualified Manufacturer Code A5X5 on tax form 5695.
