You might be familiar with heat pumps and you certainly know about water heaters, but did you know there are heat pump water heaters (HPWHs)? These hybrid appliances can control indoor climate and heat water, all while helping you save energy at home. Join us as we explore more about how a heat pump water heater works, how it can help you save money and energy, and whether it’s the right choice for your home.
How Does a Heat Pump Water Heater Work?
A heat pump water heater — also referred to as a hybrid electric water heater — uses cutting-edge technology to offer homeowners an energy-efficient option that can lower costs and reduce their carbon footprint. Heat pump water heaters don’t generate heat but rather use electricity to move heat from one location to another.
A common way to explain how HPWHs work is to compare them to refrigerators: Using the same technology that refrigerators need to operate, heat pump water heaters produce heat the same way that refrigerators stay cold. However, there is one key difference: heat pump water heaters work in reverse.
Refrigerators are designed to extract internal heat and expel it into the air, while heat pump water heaters draw in heat from the air and send it into a water tank. Inside a heat pump water heater is a compressor that concentrates the accumulated heat and transfers it to a storage tank where water can then be heated.
What’s the Difference Between a Heat Pump and a Water Heater?
A heat pump water heater (HPWH) is considered efficient because this dual-purpose appliance combines a heat pump and a water heater.
A heat pump by itself is used to regulate climate control by moving heat. Heat pumps can remove heat from cool spaces and use that heat to warm others, leaving the warm space warmer and the cool space cooler. This process is particularly efficient for regulating household temperatures.
While heat pumps use readily available hot air to heat and cool rooms, water heaters draw power from electricity or gas and use it to heat water.
A heat pump water heater combines the functions of a heat pump and a water heater. Using only heat pump technology makes heat pump water heaters more energy-efficient.
What Do I Need to Know About Electric Water Heaters?
Forty percent of residential homes use conventional electric water heaters for water heating purposes, and electric water heaters are the second-highest contributor to household energy bills.
Most water heaters use electricity to operate — even heat pump water heaters. But some electric water heaters use more electricity than others and lack energy efficiency.
Storage water heaters have been the most conventional choice for water heaters. Storage tank water heaters have large storage tanks that can hold between 20 and 80 gallons of hot water and remain full constantly. When hot water is used and removed from the tank, it is immediately replenished by cold water that gets heated.
Because storage water heaters are continually filling and heating in an attempt to maintain water temperature — a process fueled by natural gas, fuel oil, propane, or electricity — these water heaters waste enormous amounts of energy. Storage water heaters powered by gas or oil can also perpetuate energy loss when venting.
This repeated waste of excess energy is referred to as standby heat loss. Although storage water heaters have lower upfront costs, they can cause operational costs, utility bills, and electricity bills to be more expensive in the long run.
A typical storage water heater has a lifespan of 10 to 15 years.
Tank insulation, fan fixtured gas water heaters, and sealed combustion water heaters can help reduce energy loss and save on energy bills.
Do Tankless Water Heaters Save Energy?
Tankless water heaters, also commonly referred to as instantaneous or demand-type water heaters, do not have a tank and do not constantly generate hot water. Instead, tankless water heaters heat water directly and only when needed.
When hot water is summoned through the faucet, cold water will flow into the tankless water heater. The cold water is then heated with gas or electricity.
Tankless water heaters may not constantly heat and produce a reserve of hot water, but that doesn’t mean they can’t supply a constant flow of hot water when required. It just means they might not be able to produce as much hot water for as long. For example, a house equipped with a tankless water heater may not meet the water demand for multiple showers at a time.
However, tankless water heaters can produce between two and five gallons (7.6-15.2 liters) of hot water every minute, depending on whether the water heater is powered by electricity (two gallons) or gas (five gallons); the installation of a secondary tankless water heater can help meet demand.
Tankless water heaters may be limited compared to storage water heaters when purchased for homes that generate a high amount of hot water use. Still, they are more energy-efficient and save money down the road.
According to the Department of Energy, households with tankless water heaters that require 41 gallons of hot water each day are approximately 24-34% more efficient than their storage tank counterparts.
Households that need a higher hot water output, close to 86 gallons daily, can still be between 8-14% more energy-efficient than conventional water heaters.
What’s more, a tankless water heater has almost double the lifespan of a storage water heater and can last for up to or over 20 years.
Why Are Heat Pump Water Heaters Energy-Efficient?
Water heating accounts for 13% of residential energy use in the United States and is the second-biggest consumer of household energy. A significant home improvement project to reduce energy consumption would be to install a heat pump water heater.
Heat pump water heaters do not generate direct heat. Instead, they pull heat that is already present from the air. This process alone renders heat pump water heaters about three times more energy-efficient than a conventional electric water heater, depending upon the kind of heater.
Heat pump water heaters also only use between one-third and one-half of the energy used by traditional electric or gas heaters.
This energy conservation makes them 300-400% more efficient than their gas or electric heater counterparts, which produce heat through carbon-based means such as combustion.
Not only do heat pump systems require less energy to perform the same job at the same level of proficiency, but they don’t release emissions and help mitigate air and climate pollution that arises from a typical water heating system.
Heat pump water heaters can also function as a form of clean energy storage, which can help meet grid demands during peak power hours.
Acting as thermal batteries, electric heat pump water heaters can store solar energy produced during the day and lessen the need to use electricity at night when power is in greater demand but less abundant.
Heat pump water heaters equipped with electric resistance heat (hybrid hot pump water heaters) can be programmed to shift from standard operation to electric operation when the demand for hot water is high.
Some heat pump water models offer different settings, including high efficiency and economy modes, which use only the heat pump to heat water, and vacation mode or timer mode, which can turn on sleep mode until needed again.
In total, heat pump water heaters afford homeowners clean, energy-efficient heating and cooling options that prevent pollution and produce no emissions.
Will My Heat Pump Water Heater Work If It’s Cold Outside?
Heat pump water heaters use heat from the surrounding air to function, so it makes sense that homeowners would question their effectiveness in colder climates. Depending upon the air around them, heat pump water heaters will work differently.
Heat pump water heaters will not be as effective or work as efficiently in cold climates, and installation in warm places with pronounced heat will make them more efficient.
However, that’s not to say that heat pump water heaters can’t be used in cooler climates. It just means their installation needs to be more carefully considered.
Heat pump water heaters reach maximum efficiency in colder climates when installed in the basement or furnace room, and they operate best in warmer climates when installed in a garage or vented utility closet. Because they source heat from the air, any air-source heat pump system will operate more efficiently in a warm environment.
Different installation sites can still allow for year-round, in-home heat pump water heater use regardless of temperature. In addition, HPWHs will still require only half the amount of energy that traditional electric water heaters need, even if operating in cold conditions.
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What Type of Heat Pump Water Heater Is Right For Me?
Though the basic function and design of the pump itself are the same across most brands and models, different heat pump water heaters can collect and store heat in various ways.
Standalone Heat Pump Water Heaters
Standalone heat pump water heaters contain water storage tanks and provide a backup system. For example, it can be used if the need for hot water exceeds the function of the pump or if the air temperature is too cold for the pump to operate correctly.
Air-Source Heat Pump Systems
Heat pumps can also be installed to work with conventional water heater storage. Air-source heat pump systems can provide efficient space heating and cooling. Air-source heat pumps can help regulate climate control as they pull heat out of the air.
You can also install combination air-source heat pump systems that combine heating, cooling, and water heating. These combination systems also pull heat indoors from outside in the winter; they reverse to remove heat from indoors in the summer.
Hybrid Heat Pump Water Heaters
Hybrid heat pump water heaters have resistive heating elements, which offer a backup heating source when the demands are high, or temperatures are low, and the HPWH can’t keep up. These HPWHs are suitable for smaller households and are best equipped to serve two to three residents.
Hybrid water heaters use half the amount of electricity traditional electric water heaters do. For larger households, a pure heat pump water heater might be the more efficient option.
Geothermal Heat Pumps
One of the most modern heat pumps for homeowners to consider is the geothermal heat pump, which can heat and cool a home. Geothermal heat pumps will pull heat from under the ground during cold months and from the air during the warmer months.
Geothermal heat pumps are an excellent option for those in colder climates. Since they pull heat from the ground, the outside temperature doesn’t matter. Geothermal heat pumps can heat water when fixed with a desuperheater.
A desuperheater is an auxiliary heat exchange mechanism that heats water via superheated gases produced by the geothermal pump compressor. Once the water has been heated, it travels through pipes to the water tank to be stored.
Desuperheaters can also be attached to tankless water heaters and utilize excess heat that would have been discarded as waste. Desuperheater attachments are most effective in the summer.
How Much Money Can I Save With a Heat Pump Water Heater?
Energy Star, a program developed by the United States Environmental Protection Agency (EPA) and the Department of Energy (DOE), was established to promote energy-efficient appliances. Energy Star tests and certifies appliances and gives them a stamp of energy-efficient approval. These energy-efficient options can promote energy savings and cut homeowner energy costs.
Energy Star-certified heat pump water heaters can save you over 50% on water heating costs.
For a family of four, that can add up to $350 of yearly savings and $3,500 of lifetime savings. Moreover, the savings for a family of four will make up for initial costs in just two years. The larger the family, the more significant the savings will be.
Incredibly, the total energy costs in the U.S. would reach approximately $12 billion per year in savings if every HPWH under 55 gallons was an Energy-Star certified. This change would also prevent 140 billion pounds of greenhouse gas emissions from being released into the environment each year — an amount equal to the pollution caused by over 13 million cars.
Heat pump water heaters have higher upfront costs than a standard electric water heater. But this initial cost is compensated by lower operating costs and lower electricity bills, saving homeowners more money in the long run.
Can I Get Utility Rebates or Tax Incentives For My Heat Pump Water Heater?
Yes! The federal government offers a federal tax credit for Energy Star appliances that are energy efficient.
Electric powered heat pump water heaters, and air source heat pumps that are Energy Star-certified and meet tax credit criteria can receive up to a $300 tax credit.
The Energy Star rebate finder is a search base to help you find rebates applicable to your appliances.
Enter your ZIP code and choose the appliance you’re looking for, and Energy Star will present you with available rebates and guide you to the forms needed to apply for a tax credit.
Also, be sure to find out if your local government or utility company offers incentives or discounts, too.
Heat Pump Water Heaters: The Wave of the Future
Heat pump water heaters use modern technology to give homeowners the best of both worlds: They offer space heating and cooling and water heating while helping you save energy and money. Use the information in this guide to determine if a heat pump water heater is the right choice for your household. For more helpful ways to conserve energy (and funds), learn more about HVACs and other options as well as top seasonal energy tips.
Brought to you by energysavings.com
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