What is a Heat Pump: A Complete Guide to Principles and Applications

Think heat pumps are just for heating? Actually, heat pumps are far more versatile than most realize. Unlike traditional boilers or gas furnaces that generate heat through combustion, a heat pump is an electric-powered heat mover: it transfers warmth from low-temperature environments to maintain your desired indoor climate, offering both eco-friendliness and cost efficiency.

In this article, we’ll explore how heat pumps work, their different types and functions, and how to choose the right system. Discover how a single heat pump can provide year-round comfort across a variety of applications and living spaces.

What Is a Heat Pump?

From a scientific perspective, a heat pump is an electrical device, transfers energy efficiently for heating and cooling. Rather than generating heat or cooling directly, it uses a small amount of electricity to move thermal energy from a low-temperature source (such as outdoor air, soil, or water) to a higher-temperature environment, like your living space or domestic hot water. This transfer principle makes heat pumps far more energy-efficient than conventional systems, delivering significant savings.

Three Core Functions of a Heat Pump:

Winter Heating: Extracts heat from the air, ground, or water and transfers it indoors to warm your space.

Summer Cooling: Reverses the cycle via a four-way valve to expel indoor heat and to cool your space.

Year-Round Hot Water: Some heat pumps can supply sanitary hot water, either independently or integrated with heating and cooling, meeting both residential and commercial needs.

With rising global demand for sustainable climate control, heat pumps are increasingly becoming the cornerstone of modern HVAC systems.

Heat Pump vs. Air Conditioner: What’s the Key Difference?

Heat pumps and air conditioners may look similar: they both provide cooling. But the biggest difference lies in heating capability:

Air Conditioner: Cools indoor spaces by transferring heat outside. To provide heating, it must be paired with an additional furnace or boiler.

Heat Pump: Thanks to a reversing valve, it can operate in both heating and cooling, extracting heat from the outdoors and transferring it indoors for heating, while also providing cooling in summer.

In other words, a heat pump is more than just an AC; it delivers year-round comfort, combining heating, cooling, and the ability to supply stable domestic hot water all year round.

Heat Pump Types

Heat pumps are highly versatile, and different types are designed to meet specific application needs. Selecting the right heat pump for your scenario ensures maximum comfort and energy efficiency.

Tips: When deciding which type best suits your market or project, it’s recommended to consult with a professional heat pump manufacturer for an assessment and the optimal solution.

1. By Energy Source

Air Source Heat Pump (ASHP): Uses outdoor air as the heat source. Easy to install and moderately priced, ASHPs are the mainstream choice for residential and small commercial applications. Based on the output medium, they can be further divided into:

Air-to-Water Heat Pump: Transfers heat to an indoor water circulation system, compatible with underfloor heating, radiators, and hot water supply. Ideal for new homes or households needing full-house heating plus hot water.

Air-to-Air Heat Pump: Directly delivers heated or cooled air, functioning like an air conditioner but with higher energy efficiency. Best suited for spaces requiring temperature control without hot water, such as renovated homes or small offices.

Water Source Heat Pump: Uses stable water sources like rivers, lakes, or groundwater. Offers high heat exchange efficiency and stable operation. Suitable for homes, hotels, or commercial buildings located near a reliable water source.

Ground Source Heat Pump: Extracts heat from the soil via buried pipes. Maintains high heating efficiency in winter even at extremely low temperatures, making it ideal for large buildings in cold regions, such as villas or shopping centers. Initial installation requires excavation and is 2–3 times more expensive than ASHPs, but the system has a long lifespan and lower long-term operating costs.

2. By Structural Design

Different heat pump designs vary significantly in installation method, temperature control range, and suitability for residential or commercial use:

EVI Low-Temperature Heat Pump: Designed for extremely cold climates, these units use Enhanced Vapor Injection (EVI) technology to maintain high performance even at very low temperatures. With a two-stage compression process and refrigerant injection at the compressor mid-stage, EVI heat pumps operate efficiently below freezing.

Ducted Heat Pump: Efficiently distributes warm or cool air throughout a building. Heat is transferred from outdoor air to a water circulation network, typically using an indoor unit (hydronic air handler) that delivers the heated or cooled water to radiators, underfloor heating, or fan coil units for consistent, even indoor temperatures.

Split Heat Pump System: Unlike ducted systems, split units operate without ductwork. They consist of an outdoor compressor and one or more wall-mounted indoor air handlers. Each indoor unit can be controlled independently, allowing personalized comfort and energy efficiency for different areas of a home.

VRF (Variable Refrigerant Flow) System Heat Pump: An advanced HVAC system that adjusts refrigerant flow according to the heating or cooling demand of each indoor unit. VRF systems can simultaneously provide heating and cooling to different areas, making them ideal for large commercial buildings.

Gas Absorption Heat Pump: Uses natural gas or propane as fuel to transfer heat. With high heating capacity and efficiency, gas absorption heat pumps are typically used in large-scale buildings.

Hybrid Heat Pump: Combines an electric heat pump with a backup gas furnace. The system switches between the two heat sources based on outdoor temperature—using the electric heat pump when conditions are moderate and the gas furnace when the heat pump alone cannot meet the demand, optimizing efficiency.

Pool Heat Pump: Specifically designed for heating swimming pools. It absorbs heat from outdoor air and transfers it to the pool water, ensuring comfortable swimming temperatures even in cooler conditions.

3. By Refrigerant Type

The choice of refrigerant is a core factor for heat pumps, with environmental impact (mainly GWP) and safety being critical considerations:

R290 (Propane): A natural refrigerant with a GWP of only 3, offering minimal environmental impact and high heat transfer efficiency. Suitable for both residential and commercial applications, R290 delivers excellent performance—but it is flammable and requires professional installation and maintenance.

R32 / R410A / R134A: Traditional synthetic refrigerants were widely used in residential, commercial, and industrial heat pumps before the widespread adoption of R290. While they provide stable performance and reasonable efficiency, their GWP is significantly higher (R32: 657; R134A: 1430; R410A: 2088). Some countries have started restricting their use, and R290 is expected to gradually replace them in the future.

Versatile Applications of Heat Pumps

Heat pumps come in a variety of types, each designed for specific functions—some focus solely on heating or cooling, while others offer multiple capabilities in a single system.

Heating Only: When set to heating mode, the heat pump absorbs heat from the external environment and transfers it indoors. Common types for this purpose include air-source and ground-source heat pumps.

Cooling Only: In cooling mode, the heat pump works like an air conditioner, removing heat from indoor spaces and releasing it outside. This mode is ideal for hot climates where indoor cooling is required.

Integrated Heating, Cooling & Hot Water: Advanced air-source heat pumps can combine heating, cooling, and hot water supply into a single system. These integrated solutions provide year-round climate control and hot water, suitable for a wide range of residential, commercial, and industrial applications.

Underfloor Heating: Heat pumps operate efficiently at low temperatures, making them well-suited for underfloor heating systems.

Pool Heating: Heat pumps can also heat swimming pools by extracting heat from the surrounding air and transferring it to the pool water—a highly effective way to maintain a comfortable swimming temperature.

Are Heat Pumps Worth Investing?

The answer is a resounding yes. Heat pumps are a smart investment, especially for those seeking long-term heating and cooling solutions. They offer significant advantages in energy efficiency, cost savings, and environmental impact.

While upfront costs may concern some, government incentives and subsidy programs available in many regions can help offset the initial investment, making heat pumps a highly accessible and worthwhile choice.

Want to know which type of heat pumps is suitable for your market? Contact PHNIX

With over 20 years of experience in air-to-water heat pump manufacturing, PHNIX offers a complete portfolio of highly efficient and energy-saving solutions for diverse markets, covering residential heating, domestic hot water, pool heating, and commercial heating applications.

Selecting the right heat pump requires careful consideration of multiple factors such as climate, space, and specific needs. If you’re looking for the optimal solution for your market, PHNIX—a professional Chinese heat pump manufacturer—can provide tailored guidance and the best-fit products for your project.

Ready to Upgrade? Explore PHNIX’s Complete Heat Pump Portfolio: http://phnix-e.com/products.html