How Does a Heat Pump Work: Everything You Need to Know
Heat pumps not only significantly reduce energy consumption, but also provide stable heating for your home during cold winters. Compared to traditional gas boilers or electric resistance heating equipment, heat pumps can achieve an efficiency ratio of 300-400%.
This article will provide a detailed analysis of the core mechanisms of how does a heat pump work, help you understand the characteristics of different types of heat pumps, and provide professional advice on installation costs, energy-saving effects and applicability.
How Does a Heat Pump Work?
Here’s the simple version: a heat pump doesn’t generate heat—it moves it.
Think of it like your fridge. Your fridge takes heat from inside and pushes it out to keep things cool. A heat pump works the other way around, pulling heat from the outside air and bringing it indoors to warm your home.
So, how exactly does a heat pump do this "moving" work? The entire process includes four key steps. Let's take a look:
Heat absorption: The refrigerant in the evaporator coil starts off colder than the outdoor air, so it absorbs heat and begins to boil, turning into a gas.
Compression and temperature rise: The gas is compressed, which raises its temperature, similar to how air heats up when it’s squeezed into a smaller space.
Heat release: The hot gas moves through the condenser coil inside your home, releasing its heat to warm the air or water. As it cools down, it turns back into a liquid.
Pressure reduction and repeat: The liquid passes through an expansion valve, dropping in pressure and temperature, and returns to the evaporator to start the process again.
This cycle repeats continuously, efficiently moving heat indoors without having to create it. And in the summer, the process simply reverses, taking heat from inside your home and sending it outdoors, just like a portable air conditioner. Whether you're heating or cooling, the heat pump delivers efficient, year-round comfort.
Different Types of Heat Pumps
Knowing how a heat pump works is a great start, but the next step is figuring out which type suits your home best. Each type pulls heat from a different source and comes with its own strengths. Here’s a breakdown to help you decide:
1. Air Source Heat Pumps
These are the most common and budget-friendly options. They're also the easiest to install, making them a great fit for most homes, especially in mild to moderate climates. There are two main types:
Air-to-Air Heat Pumps: These units absorb heat from the outside air and blow warm air into your rooms through indoor units. They're ideal if you don’t have existing radiators or underfloor heating. Installation is relatively simple, and costs are generally lower than other systems.
Air-to-Water Heat Pumps: Instead of blowing warm air, this system heats water for use in radiators or underfloor heating. How does a heat pump work to heat water? It works with your existing hydronic system, though you might need to upgrade to larger radiators since heat pump water is cooler than what traditional boilers provide.
2. Ground Source Heat Pumps
Also known as geothermal systems, they extract heat from underground where temperatures stay stable year-round, typically between 10–15°C. So, they’re often more efficient than air-source systems, especially in colder climates. There are two installation methods:
Horizontal systems use long pipe loops buried in shallow trenches, so they need plenty of yard space.
Vertical systems drill deep boreholes and are great for smaller properties, but the installation is more complex and can cost 20,000–30,000 ZAR per borehole.
3. Water Source Heat Pumps
If you live near a lake, river, or even have access to groundwater, a water source heat pump might be worth considering. Water bodies store heat well and tend to have more stable temperatures than air, which helps with efficiency. This system is divided into open and closed types.
Open-loop systems pump water directly from the source, extract heat, and then return the water.
Closed-loop systems use sealed pipes submerged in the water, which transfer heat without direct contact.
4. Hybrid Heat Pumps
Hybrid systems combine traditional heating methods with heat pump technology, giving you efficiency when conditions are right and reliable backup when they're not.
These intelligent systems automatically switch between heat pump operation and conventional heating based on outdoor temperature and your hot water demand. When it's warm enough, the heat pump does the work efficiently. When temperatures drop too low, a backup heater kicks in to ensure you never run out of hot water.
How Efficient Are Heat Pumps?
Heat pumps do not generate heat from scratch like electric heaters or gas boilers; instead, they simply move existing heat from one place to another. This method of heat transfer makes heat pumps extremely efficient.
To put it into perspective, a standard electric heater gives you one unit of heat for every unit of electricity it uses—so, 100% efficiency. Heat pumps, on the other hand, can deliver three to four units of heat using that same amount of electricity. That means they’re 300% to 400% efficient under the right conditions.
This performance is measured using something called COP, or Coefficient of Performance. It tells you how much heat is produced per unit of electricity. So, a COP of 3 means you're getting three units of heat for every unit of energy used.
Of course, real-world efficiency can vary a bit depending on the weather. In warmer months, when it’s easier to extract heat from the air, heat pumps tend to perform at their best. In colder conditions, efficiency drops a little, but even then, they often remain more energy-efficient than traditional heating systems.
How Much Does It Cost to Install a Heat Pump?
Next, let's talk about how much it costs to install a heat pump, which is the question most users are most concerned about.
Heat pump installation costs vary depending on system type, installation complexity, and geographic location.
A 4-5 kW domestic heat pump unit typically costs between more than R10,000 to R20,000, with higher prices for better brands and features.
Taking common models as an example, the purchase cost of an ordinary household heat pump (with a water tank capacity of around 200L) is approximately R15,000.
Professional installation may require an additional few thousand rand, depending on installation complexity and construction difficulty.
Plus, installation costs in developed urban areas are typically higher than in rural areas.
How Much Can You Save with a Heat Pump?
Thanks to their high efficiency, heat pumps can lead to noticeable savings on your electricity bill, especially if your household uses a lot of hot water.
Heat pumps typically have a COP (Coefficient of Performance) of around 3 to 4. In simple terms, that means for every 1 kWh of electricity they consume, they can produce 3 to 4 kWh worth of heat. In contrast, a traditional electric water heater converts 1 kWh of electricity into just 1 kWh of heat.
Let’s look at an example:
If your household uses about 150 kWh of energy per month for heating water, a standard electric heater would require the full 150 kWh of electricity. But with a heat pump operating at a COP of 4, you’d only need around 37.5 kWh to produce the same amount of hot water. That’s a monthly saving of 112.5 kWh.
At an average electricity rate of R3.70 per kWh, that translates to roughly R416 in monthly savings, or nearly R5,000 per year.
Of course, the actual savings depend on how much hot water your home uses. According to NewsCentral Media, if your daily hot water consumption is low (around 4 kWh per day), the savings might not justify the upfront cost. But if your household uses around 20 kWh per day for water heating, the switch to a heat pump can pay for itself in as little as 18 months, and the system itself can last over a decade.
If your home already has a solar power station or you’re planning to get one, the benefits are even greater. You can schedule your heat pump to run during off-peak times or while solar panels are generating, reducing reliance on the grid and lowering costs further. In some cases, it’s even possible to heat water at virtually no extra cost.
To make the most of this setup, consider pairing your heat pump with the EcoFlow DELTA Pro Portable Power Station, whose 3.6–25 kWh expandable capacity ensures you have ample backup to run high-demand appliances like heat pumps alongside essentials, while its 3600W continuous AC output (boostable to 7200W) delivers the sustained power your unit needs. With a robust LiFePO₄ battery rated for 6500 cycles, you’ll enjoy reliable performance and significant savings as your heat pump draws from stored renewable or lowcost grid energy rather than expensive peaktime electricity.
EcoFlow DELTA Pro Portable Power Station
Is a Heat Pump Right for You?
Whether you should install a heat pump requires comprehensive consideration of your household needs, usage habits, and environmental factors. The following situations are suitable for considering heat pump installation:
High Hot Water Demand: If your home has large-capacity water heaters (such as two parallel water heaters) or daily hot water consumption is high, heat pumps can maximize their effectiveness.
Living in a Warm Climate: In warm environments, in areas with higher average temperatures, heat pump efficiency is higher.
High Electricity Bills and Want to Save Money: If your current hot water electricity bills account for a high proportion and the electricity burden is heavy, then efficient heat pump systems can significantly reduce electricity bills, and can recover costs in the long run.
Additionally, some remote areas or households with frequent power outages should also consider backup power solutions. You can equip a solar generator or portable power stations.
Conclusion
By now, you’ve got a solid understanding of how does a heat pump work and why they’re so energy-efficient. Instead of creating heat from scratch, they move existing heat, allowing them to reach efficiencies of 300% to 400%.
If you’re aiming to cut down on power costs and reduce your environmental impact, combining a heat pump with a trusted power station like those from EcoFlow is a smart move. It’s a practical way to build a more efficient, flexible home energy setup.
Start making the switch today and enjoy a more comfortable, low-carbon lifestyle that’s built to save.
FAQs
How much electricity does a heat pump use per month?
On average, a household heat pump uses about 400 to 800 kWh of electricity per month, depending on your home’s size, insulation, and how much heating or cooling you need.
With electricity prices in South Africa ranging from R2 to R3 per kWh, that works out to roughly R800 to R2,400 per month.
It is 60–75% cheaper than running traditional electric heaters, thanks to the heat pump’s high efficiency. For year-round comfort and long-term savings, it’s one of the most economical options available.
At what temperature do heat pumps stop working?
Most heat pumps work efficiently in temperatures as low as -10°C to -15°C. Below this temperature, the heat pump will struggle to work and backup heating may be required. In South Africa, temperatures rarely drop this low, so heat pumps are reliable all year round. Premium models can operate in temperatures as low as -25°C, but they cost more.
How does a heat pump geyser work？
Air Heat Extraction: A refrigerant‑filled evaporator coil draws warmth from the surrounding air, even down to about 5 °C.
Compression: The vaporized refrigerant is pressurized by a compressor, sharply raising its temperature.
Heat Transfer: The hot refrigerant flows through coils inside the water tank, releasing its heat and warming the water to around 55 °C.
Expansion & Repeat: An expansion valve cools and depressurizes the refrigerant, readying it to absorb more heat and continue the cycle.
By moving heat rather than generating it, a heat pump geyser uses 60–75% less electricity compared to a conventional electric element geyser.