What is a Heat Pump?
A heat pump is an energy-efficient heating and cooling system that transfers heat rather than generating it. Using refrigerants, it absorbs heat from an external source – such as air, ground, or water – and moves it indoors for heating or outdoors for cooling.
This process makes heat pumps a cost-effective and eco-friendly alternative to gas boilers.
Download our guide on How Does A Heat Pump Work to learn more.
How Does A Heat Pump Work?
With the growing focus on energy efficiency and sustainability, heat pumps have been identified as a crucial solution for heating and cooling buildings.
At the core of every heat pump is the principle of heat transfer. This process relies on a closed-loop system containing refrigerant, a substance capable of absorbing and releasing heat efficiently as it changes from a liquid to a gas and back again. Heat pumps extract thermal energy from an external source compress it to increase its temperature, and then distribute the heat indoors.
In cooling mode, the cycle reverses, expelling unwanted heat from the building to maintain a comfortable indoor climate. This method not only reduces energy consumption but also minimises carbon emissions, making heat pumps an increasingly popular choice for sustainable heating and cooling solutions.
Air-Source Heat Pumps
Air-source heat pumps are among the most common types. They absorb heat from the outdoor air, even in cold conditions, and transfer it indoors.
One key feature of air-source heat pumps is the reversing valve, which allows them to function as both a heater and an air conditioner. In cooling mode, the process is reversed: the system absorbs indoor heat and expels it outside.
Here’s a simplified breakdown of the process:
Heat Absorption
The heat pump extracts heat from the air using an outdoor coil filled with refrigerant. The refrigerant absorbs thermal energy, even in cold weather, and evaporates into a gas as it captures heat
Compression
The refrigerant gas is compressed by the compressor, increasing its temperature and pressure. This step is crucial as it allows the refrigerant to reach a high enough temperature to provide effective heating
Heat Release
The high-pressure, high-temperature refrigerant gas moves to the indoor coil, where it releases its heat. As the refrigerant gives off heat to warm the indoor air or water, it condenses back into a liquid
Expansion & Recycling
The cooled refrigerant passes through an expansion valve, which reduces its pressure and temperature, turning it back into a low-pressure, low-temperature liquid. It then returns to the outdoor coil, where the cycle repeats
Water-Source Heat Pumps
Water-source heat pumps are an efficient heating and cooling solution for commercial buildings when a consistent water source is available. These systems are widely used due to their ability to provide stable and efficient temperature control.
Unlike air-source systems, WSHPs utilise the relatively constant temperature of water bodies to optimise performance. This results in higher energy efficiency and lower operating costs, especially in large commercial properties that require year-round climate control.
Ground-Source Heat Pumps
Ground-source (or geothermal) heat pumps operate similarly but extract heat from the ground instead of the air. This type of equipment offer a viable heat pump option because underground temperatures remain relatively stable year-round.
They use buried pipes filled with refrigerant or water to capture and transfer heat, making them an excellent option for long-term energy savings.
While ground-source heat pumps offer exceptional efficiency and sustainability, they also come with certain drawbacks that should be considered such as the complex nature of their installation and subsequent maintenance work.
Be sure to speak to a Cooltherm expert to discuss the best heat pump option for you.