A beginner-friendly guide: what is a heat pump and how does it work

Now heat pump technology has become the top choice for architects, installers, and homeowners when selecting HVAC systems for new homes. They can also be integrated into existing homes as part of energy efficiency upgrades, making them perfect for modernization replacement.

Here’s a beginner-friendly guide to know about heat pumps—from how they work to how they keep your home comfortable.

1. What Is A Heat Pump? How Does It Work?

Why do we say it “moves heat” instead of “generates heat directly”? Using a refrigerant cycle, it absorbs heat from a low-temperature source (like outdoor air, ground or water), then compresses and heats this refrigerant to release the stored heat into a higher-temperature space (such as your home). 

This process is similar to a refrigerator operating in reverse: while a fridge moves heat from its inside to the outside, a heat pump moves heat from the outside into your home.

Take an air-source heat pump as an example—here’s how it works:

(1)Evaporation: The evaporator is the place where refrigerant and outdoor air exchange heat, turning the refrigerant from liquid to gas as it absorbs the heat from the air.

(2)Compression: After evaporation, the refrigerant enters the compressor, which compresses it into a hot, high-pressure gas for the condenser.

(3)Condensation: The condenser is the place where refrigerant and water exchange heat, turning the refrigerant from gas into liquid as it releases the heat to water.

(4)Expansion: After condensation, the liquid refrigerant flows through an expansion valve, reducing pressure and turning it back into vapour, and then goes into the evaporator for the next cycle.

2. Core Advantages of Heat Pumps vs. Traditional Heating Systems

(1)High Efficiency & Cost Savings

Heat pumps use far less electricity than traditional boilers to deliver the same amount of heat. This means lower energy bills and reduced energy waste.

(2)Lower Carbon Footprint

By minimizing electricity use and avoiding fossil fuels (like gas or oil), heat pumps slash CO₂ emissions, supporting a greener, more sustainable future.

(3)One-stop Comfort

Heat pumps provide year-round solutions: heating in winter, cooling in summer, and even hot water production. Their flexible design allows seamless integration with solar panels (PV systems) and battery storage for smarter energy use.

(4)Energy Independence

No more worries about fossil fuel shortages or price spikes driven by geopolitical issues. Heat pumps break your reliance on oil and gas, insulating you from market volatility.

3. What Can A Heat Pump Do?

Versatile Applications for Homes

• Heating:
Compatible with radiant floor heating, radiators, fan coils, and other distribution systems. Maintains cosy indoor temperatures of 22–25°C in winter.

• Cooling:
Delivers energy-efficient cooling in summer via fan coils or air handlers, operating more efficiently than traditional air conditioners.

• Hot Water:
Provides year-round domestic hot water, replacing electric or gas water heaters.

4. Types of Heat Pumps and Their Differences

Heat pumps harness energy from air, water, or the ground. Based on their energy sources, they are categorized into three main types—all of which can reverse their operation in summer:

(1) Ground-Source Heat Pump (GSHP)

• Uses underground collectors or probes to extract heat from the ground.

• Transfers this heat to your home’s water circuits for heating and hot water production.

(2) Air-to-Air Heat Pump

• Absorbs heat from outdoor air.

• Directly distributes warmth into rooms through ventilation systems.

(3) Air-to-Water Heat Pump

• Absorbs heat from outdoor air.

• Transfers it to your home’s water-based heating systems (e.g., radiators, underfloor heating, or other heat emitters).

• Best-selling and most popular type: Combines versatility with high efficiency.