How air conditioning works

Efficient comfort, advanced technology

Cooling down the summer heat with air conditioning is becoming an increasingly popular option. According to data from the International Energy Agency, energy consumption for space cooling is expected to double by 2050, and Eurostat figures reveal that more than 63% of the energy needs of EU households are related to heating systems.

Opting for increasingly efficient equipment, that is, equipment capable of achieving the desired results with the minimum possible resources, is a good starting point, although not the only one. Other systems, such as aerothermal energy, have been making a name for themselves in the air conditioning market for some time. Understanding how the different air conditioning options work and analyzing the particular needs of each home is key to finding the most suitable solution.

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How does an air conditioner work?

Ducted, portable, split... There are different air conditioning systems, but they all share the same principle that answers the question of how an air conditioner works. Basically, they all use a refrigeration cycle that allows heat to be extracted from a space and expelled to the outside. To achieve this, in addition to a refrigerant gas, different components are involved, each of which performs a specific function:

Compressor. This is the “heart” of the system. It is responsible for compressing the refrigerant gas, which, when pressurized, increases its temperature. The efficiency of the compressor determines how much it needs to work to maintain the desired temperature, which directly influences the energy consumption of the air conditioner.
Condenser. Once the gas is compressed, it is transferred to the condenser, where it releases heat to the outside and condenses into liquid form. As with the compressor, the design and materials of this second component also affect the speed at which the system can cool the refrigerant gas and, consequently, the overall efficiency of the system.
Expansion valve. Here, the refrigerant liquid undergoes a rapid decrease in pressure, lowering its temperature before passing to the evaporator. In essence, what this part of the system does is “restrict” the gas.
Evaporator. Finally, the refrigerant passes to the evaporator, where it absorbs heat from the interior air, cooling it. Thus, the cold air is forced into the interior space while the refrigerant gas returns to the compressor to begin the cycle again.

Aerothermal energy: how it works and characteristics

Understanding how air conditioning works is essential to understanding its differences and similarities with another HVAC system that is gaining popularity in the heating and cooling sector: aerothermal energy. Although it uses some principles similar to those of air conditioning, the latter is characterized by being a more efficient and environmentally friendly alternative. Why? Basically because this system uses the energy in the air (a renewable source) to generate heating, cooling, and domestic hot water (DHW) that requires minimal electricity consumption to operate.

The aerothermal thermodynamic cycle works by means of a heat pump, which captures and transforms ambient energy. This heat pump transfers the energy from the air to the refrigerant fluid, which in turn heats the water or air that is distributed throughout the home via radiators or underfloor heating. As for the cooling mode, the system can cool the air and distribute it like an air conditioner.

This ability to capture and transform energy from the outside air largely explains its greater efficiency compared to other conventional systems. Aerothermal energy uses up to 75% of energy from the outside air, combined with 25% from electricity, which in practice translates into savings in energy consumption. To this we must add that it also reduces CO₂emissions and minimizes the environmental impact (by using the latent heat from the air as an energy source).

Efficiency in HVAC systems

The efficiency of heating and cooling systems is confirmed by indexes such as the SEER (Seasonal Energy Efficiency Ratio or summer scale) or the SCOP (Seasonal Coefficient of Performance or winter scale), which are responsible for calculating the performance of different systems such as air conditioning or aerothermal energy. Based on this performance, for example, they will be given a rating that will determine the corresponding energy label.

However, putting into practice the manufacturers' recommendations or surrounding yourself with the appropriate 'allies' is essential to ensure the efficiency of the equipment. Some of the essential recommendations relate to:

Integration with renewable energies.
Both air conditioning and aerothermal energy can work together with photovoltaic solar panels to supply their electricity demand, which, in practice, reduces the environmental impact of HVAC systems.
Optimization technologies.
Inverter compressors, smart thermostats, and motion sensors, for example, help reduce energy consumption by adapting the operation of the system to demand. Similarly, home automation and energy management applications also help make a more efficient use of systems, whether it be aerothermal energy or air conditioners, by predicting consumption, allowing them to be activated remotely, enabling eco mode, etc.
Complementary actions.
When it comes to optimizing HVAC systems, it is not only important to understand how air conditioning works or what the advantages of aerothermal energy are. It is also essential to know that by paying attention to some basic issues, it is possible to improve performance. Something as simple as avoiding opening doors and windows when the air conditioner or aerothermal system is in use, or accompanying its operation with the use of blinds or awnings, also contributes to making a more efficient use of energy.

Efficiency, responsible consumption, and renewable energies

The gradual evolution of HVAC systems, in terms of efficiency and integration with renewable energies, is an indisputable reality. Not only are consumers increasingly interested in investing in this type of equipment, but companies are also contributing their technologies and experience to make heating and cooling and energy use an increasingly environmentally friendly sector.

Repsol's commitment to energy efficiency and responsible energy consumption is part of our Energy Transition Strategy. Our projects range from initiatives aimed at developing and integrating renewable energy technologies, such as aerothermal energy or solar panels, to promoting solutions that promote responsible and optimized energy consumption.

Through the Vivit app, for example, we help users manage and reduce their electricity consumption efficiently. The tool not only allows you to monitor energy use, but can also be used to set consumption targets and obtain personalized recommendations to improve energy efficiency at home.