AEROTHERMAL IN SPAIN

Aerothermal energy in Spain: what is it, how it works and what its advantages are

In a world where efficiency and care for the planet are becoming more and more of a priority, aerothermal energy is one of the most innovative and sustainable solutions for heating and cooling homes in Spain.
Everyone likes to have a comfortable temperature at home, not too hot or too cold, and without it costing too much on their electricity bill. At the same time, there is growing concern about the environmental impact of heating and air conditioning, traditionally based on fossil fuels. Electrification is a key solution, as it promotes the use of electricity from renewable sources, such as wind and solar power.

Iberdrola España promotes aerothermal energy as one of the most efficient and sustainable technologies in this energy transition. This system, by harnessing energy from outside, provides heating, cooling and hot water. It also saves energy for families. A family home can save up to an estimated €1,000 annually with aerothermal energy.

Never heard of it? We’ll tell you what it is, how it works and its advantages.

What is aerothermal energy and what is it used for?

Aerothermal energy is a sustainable air-conditioning and heating system for homes and buildings. It pulls energy from the outside air to generate heating in winter, cooling in summer and hot water all year round. This technology replaces traditional heating equipment using fossil fuels, such as gas or oil boilers, with a cleaner and more efficient option.

By running on electricity, especially when it comes from renewable sources, aerothermal energy contributes directly to decarbonisation, reducing CO₂ emissions.

How does aerothermal work?

Aerothermal energy operation is based on two elements, which provide heating in winter and cooling in summer, as well as hot water all year round:

Outdoor equipment or compressor outside the home and that is responsible for extracting energy from the ambient air, which is free and renewable.
Indoor equipment or hydraulic module located indoors. Through a closed circuit, it converts air energy into heat or cold, depending on the need. It heats and stores water that is then distributed to taps, radiators and underfloor heating to generate heating and renewable hot water in winter. And in summer, it reverses the process, generating cold water to cool your home.

This is how it works:

Air energy extraction (primary circuit): the outdoor unit of your house extracts energy from the ambient air. It uses refrigerant fluids in a thermodynamic cycle to transform the air into a liquid state.
Refrigerant compression and transformation:
- the compressor raises the refrigerant’s pressure and converts it into a gas.
- the condenser condenses the gas and transforms it back into liquid.
- the expansion valve reduces the temperature, causing the fluid to expand.
- the evaporator evaporates the fluid to restart the cycle.
Water cooling or heating (secondary circuit): the internal hydraulic module cools or heats the water and distributes it for heating, cooling or domestic hot water according to your household’s needs.

In addition to aerothermal energy, which uses air-water technology, there are other heat pumps that also make use of the thermodynamic cycle.

Types of aerothermal heating

The most common aerothermal heating systems are:

Underfloor heating: this is the most efficient system as it distributes heat evenly through pipes under the floor.
Radiators: this is a viable option that requires a checking homes that already have radiators installed beforehand.
Fan coils: these are devices that transmit heat or cold by means of units that combine a fan and a heat exchanger.

Advantages of aerothermal heating

Aerothermal energy offers numerous advantages for both you and the environment. These are its main benefits:

Higher efficiency

Aerothermal energy is four times more efficient than a conventional boiler.

Sustainability

Unlike the gas boiler, the heat pump system is considered a form of renewable energy, which uses air, a free and inexhaustible source.

Less CO₂ emissions

Heat pumps emit up to 70% less CO₂ emissions than gas boilers.

Savings

You can cut your electricity bill by up to 75%.

Convenience and safety

This system does not require complex maintenance and does not depend on fuels, so there is no risk of explosion from leaks.

How aerothermal energy is transforming the use of heat pumps in Spain

A new European Union directive requires public buildings to replace old heating and cooling equipment with efficient alternatives.

Starting in January 2026, new public buildings will have to be zero-emissions, and starting in January 2028, this measure will apply to all new buildings.

These measures are a challenge. Today, heat pumps are a booming option. In Spain, more than 11 heat pump air-conditioning systems were sold in 2023 per 1,000 households; in Nordic countries like Norway, more than 50 units per 1,000 households were shipped, according to the European Heat Pump Association (EHPA).

Iberdrola España's aerothermal services: the renewable heating system

At Iberdrola España we offer a wide range of aerothermal solutions, setting them up new homes and replacing old boilers with more sustainable systems such as aerothermal.

The service is personalised and adapted to the needs of your home. If your home already has heating, you would only need to change one piece of equipment for another.

As a renewable technology, aerothermal energy enjoys tax deductions to encourage use and installation. At Iberdrola España we can advise you on subsidies and financing.

Synergy between solar panels and aerothermal

Photovoltaic self-consumption and aerothermal energy are the perfect combination to achieve greater energy efficiency in homes.

The solar panels generate enough electricity to cover 25% of the power that the aerothermal system needs to operate, making the heating, cooling and hot water system practically free of charge in optimal sunny conditions.

Thanks to this synergy, non-renewable energy consumption is reduced and consumers can make the most of the renewable energy available in the environment, reducing conventional energy demand by up to 60%.
We can, for example, program the equipment to use surplus hot water production and keep the hot water tank at a suitable temperature for use when washing or showering.

This not only saves you considerable money on energy bills, but also helps to reduce CO₂ emissions.
necesita para funcionar, haciendo que, en condiciones óptimas de sol, el sistema de calefacción, refrigeración y agua caliente sea prácticamente gratuito.