Aerothermal energy: present and future of energy efficiency

Nearly zero energy consumption buildings (EECN) are one of the main bets of the European Union to achieve "reducing greenhouse gas emissions by at least 40% by 2030 compared to 1990," as established in the 2018/844 regulation. The goal is to "guarantee a highly energy efficient and decarbonized national real estate stock and facilitate the economically profitable transformation of existing buildings into nearly zero energy consumption buildings." In this article, we will explain what aerothermal energy is, as well as its benefits in terms of energy efficiency and economic savings.

What is aerothermal energy?

Aerothermal energy allows you to obtain hot water and achieve adequate indoor air conditioning through the use of outdoor air, without generating direct CO2 emissions, using a heat pump. These devices reverse the refrigerant cycle by introducing hot air in winter, as the indoor unit acts as a condenser and the outdoor unit as an evaporator. In summer, it works by providing cold air; in this case, the indoor unit functions as an evaporator and the outdoor unit as a condenser. This energy source is considered sustainable: the use of outdoor air is unlimited, it does not produce combustion, and therefore does not generate smoke or any type of combustion.

Energy Saving

The installation of these systems is easy with simple maintenance and is safer than traditional boilers. Furthermore, it serves as a way of achieving monetary savings that can range from 50% to 80% depending on the type of previous installation. The energy efficiency of this air conditioning system occurs by obtaining up to 80% of the energy from the air. This fact leads to heat pumps exponentially multiplying the electrical power of the compressor, significantly increasing the overall efficiency:

• For every kW of electricity that a heat pump uses in heating mode, it obtains 4.5 kW of heat

• For every kW of electricity that a reversible heat pump uses in air conditioning mode, it obtains 3.5 kW of cooling

In this way, aerothermal energy presents itself as the solution with the highest long-term savings rate since the usability costs, despite the initial investment, are negligible compared to other systems. In fact, the average price to heat 1 kWh (based on 2020 data) is:

• Electricity: €0.142/kWh (Electric radiators)
• Pellets: €0.085/kWh
• Diesel C: €0.084/kWh (Thermal boiler)
• Accumulator: €0.078/kWh
• Natural gas: €0.055/kWh (Thermal boiler)
• Aerothermal energy: €0.041/kWh

As we mentioned earlier, with aerothermal energy we achieve a system for heating, air conditioning, and hot water production. Thus, we centralize several systems into one, exponentially increasing the efficiency achieved, economic savings, and maintenance costs. We are also saving in terms of space occupancy. This grouping of functions makes the overall system more affordable both in acquisition and usability (including maintenance) since the number of components decreases significantly. On average, the savings obtained enable amortizing the investment after a maximum of five years, achieving higher returns if combined with other renewable sources like photovoltaic panels or if installed in spaces with quality thermal insulation. Under optimal conditions, it is possible to achieve performance coefficients higher than 400% or COP4.

Aerothermal energy for homes and the advantages it brings:

• Possibility of combining it with other thermal emitters such as radiators or underfloor heating
• Adaptable to existing installations.
• Requires little space
• It is a completely safe system