Views: 20 Author: Site Editor Publish Time: 2025-06-19 Origin: Site
Heat pump water heater is an innovative and energy-efficient solution for providing hot water in homes, businesses, industries, etc. Its working procedure involves the use of significantly less energy than conventional water heaters, making it an attractive option for people looking to reduce their energy consumption and environmental impact.
Knowing how a heat pump water heater works allows you to optimize its performance, troubleshoot minor issues, make informed decisions about its use & maintenance, and appreciate its impact on the environment.
In this article, we will explain how a heat pump water heater work, and why it is the perfect solution for providing hot water in your home and business place.
A heat pump water heater (HPWH) is an appliance that transfers heat from the surrounding air or ground, into a water tank in order to provide hot water for use in homes, offices, industries, healthcare facilities, etc. It uses electricity to collect outdoor heat and moves it to a storage tank filled with water. The hot water is then passed through pipes into various water channels (taps, sinks, showers, bathtubs, & dishwashers).
This process of moving heat rather than creating it, is why the HPWH is significantly more efficient than conventional water heaters (like the electric & gas water heaters). It saves up to 60-70% energy by doing this, and is estimated to cost less (about -41%) to operate per year.
Now that you have an idea of what is hot water heat pump, let’s dive into heat pump water heater how it works.
To understand how this appliance works, imagine an air conditioner or a refrigerator working in reverse. These two devices are able to execute cooling effects because they move heat from cold areas to warmer areas. In reverse, the heat pump water heater provides hot water by moving heat from a warm area (the environment) to a cold area (the water tank).
Now, let’s explore its various components and how they work together to produce hot water.
● Evaporator: It absorbs heat from the ground or surrounding air. Various refrigerant-filled tubes are stationed at the top of this unit.
● Fan: The fan moves air over the evaporator to make absorption of heat easier.
● Air Coils: These coils are responsible for extracting heat from the surrounding air, and transferring it to the refrigerant in the evaporator.
● Compressor: It increases the temperature and pressure of the heat absorbed from the surrounding. The compressor is considered the major working component of a HPWH.
● Condenser: This is a coil wrapped around the water tank. It's function is to transfer heat to the water.
● Expansion Valve: It regulates the flow of liquid refrigerant across the heat pump system.
● Insulated Storage Tank: Stores the heated water till it is ready for use. It is connected to the home through pipes.
● Controls: Helps to monitor the entire water heating system and enable it to operate smoothly & efficiently.
The step-by-step process of how a heat pump water heater work is explained below.
The fan attracts and draws hot/warm air from the surrounding into the air coils of the evaporator (which acts as the first heat exchanger). Cold refrigerant present in the evaporator then absorbs heat energy from the air and gets turned into vapor.
This vapor is sent through a compressor which increases the temperature of the refrigerant by squeezing it into a smaller volume (gas becomes hotter when its pressure is increased). Aside from increasing the refrigerant’s temperature, this process also prepares the refrigerant for the efficient transfer of heat to the water tank.
Next, hot refrigerant from the compressor flows through a series of coils (condenser) wrapped around the water tank, and transfers its heat to the water. As the refrigerant loses its heat, it cools off and is condensed to its original liquid state.
The liquid refrigerant then passes through the expansion valve where it cools rapidly and expands. After undergoing the cooling process and changing back to cold vapor, the refrigerant returns to the evaporator and the cycle is repeated.
Why the concept of moving heat (which the HPWH adopts) is better than generating heat is that it requires less energy to transfer existing heat than to create it from scratch. When you compare the characteristics of the heat pump water heater vs gas and other traditional water heaters, the use of HPWH is a more economical & sustainable solution for domestic and commercial hot water requirements.
The types of heat pump water heater are grouped into two classes.
● Integrated Heat Pump Water Heater: These are heating systems where the heat pump and insulated storage tank are combined into a single unit and placed outside the house. They are easier to install.
● Split System Heat Pump Water Heater: These heating systems have the storage tank located inside the house while the heat pump unit is located outside the house. They are connected by refrigerant lines. This configuration can be used in homes or workplaces where there is limited space.
● Air-Source Heat Pump Water Heater: These are the most common type of heat pump water heater. They absorb heat from the surrounding air and send it to the stored water.
● Ground-Source (Geothermal) Heat Pump Water Heater: The heat pump in this system absorbs heat from the ground or a nearby water-body and transfers it to water stored in the tank. While they are more efficient, their installation cost is higher.
● Low Energy Consumption: HPWH are significantly energy-efficient. By transferring heat, they consume less electricity than they would have if they were generating it.
● Eco-friendly: They have less negative impact on the environment because they consume a low amount of energy and do not emit greenhouse gases. They also dehumidify the air around the space where they are located.
● Tax Incentives & Rebates: In a bid to encourage sustainable lifestyle among citizens, many state and local governments offer utility rebates and tax incentives. As a benefactor, you can receive as much as 30% tax credit for up to $2,000.
● Minimal Cost: Using a heat pump water heater can save you a lot of money. The operation cost is lower than other traditional water heaters due to its high energy-efficiency, so it can help you save hundreds of dollars annually.
● Maintenance Practices: HPWH doesn't require strenuous maintenance practices. The maintenance process includes annual flushing of the water tank to reduce sediment buildup, inspection & replacement of anode rod, and cleaning & replacing air filters to ensure optimal airflow.
● Lifespan: The average lifespan for a heat pump water heater is 10-15 years. However, some HPWH can last longer (maybe as long as 20 years) if they are well taken care of and not exposed to heavy usage or harsh working conditions.
As numerous as the benefits of a hot water heat pump are, there are some things you must consider before you purchase one.
● Upfront Cost & Installation Requirement: This appliance is somewhat expensive to purchase. It typically costs about $1500 to $3000 but the tax incentive provided by the governments of various regions can help reduce that cost. The installation can also be costly, as it includes the presence of a technical expert, adequate space & ventilation, and a proper condensate drainage.
● Climate Limitation: Heat pump water heater works most efficiently in warm climates. Its operation is affected in cold weather because there is less heat to extract from the surrounding air as the temperature gets colder. It is not suitable for regions with temperature less than 40oF.
● Space Requirement: The amount of airspace needed for installing a HPWH is about 1,000+ cubic feet (28,3m3) and the temperature within this location must be around 40oF-90oF (4.4oC-32.2oC). The space must also be well-ventilated to maximize heat extraction. Ideal locations include outdoor basements, garages, or utility rooms.
This post on how a heat pump water heater works illustrates how HPWH uses electricity to transfer heat from the surrounding air or ground to heat water, rather than generating heat directly. This process is why it is a highly efficient alternative to traditional water heaters.
When purchased from a reliable hot water heat pump manufacturer, It has the ability to reduce your carbon footprint, energy consumption, and cost of living.
