Aerothermal heat pumps in Marbella: what it is and how installation works

What aerothermal energy is and how it works

An aerothermal heat pump works on the same principle as an air conditioner, but extended to heating and hot water as well: a compressor moves refrigerant that absorbs heat from the outside air — even when it's cold outside — and transfers it into the home's water circuit, or into the air for climate control. In summer the cycle can run in reverse to cool the home. The advantage over a boiler or an electric water heater is that most of the energy the unit delivers comes from the air, not from electricity consumed directly.

Why it fits the Marbella and Costa del Sol climate

Aerothermal heat pumps perform better the milder the outside temperature, because the compressor has to work less to pull heat out of the air. Marbella's climate, with mild winters and long summers, is exactly the kind of setting where this equipment runs under favourable conditions for most of the year — for both heating and cooling.

What an aerothermal heat pump can cover

In a home on the coast, a single aerothermal unit can cover three needs: cooling in summer, heating in winter (when paired with underfloor heating, fan coils or low-temperature radiators), and support for, or full production of, domestic hot water. Not every unit covers all three at once — it depends on the model and how the installation is sized — which is why a technical visit always comes first.

How the installation process works

An aerothermal installation has more moving parts than a wall-mounted split, because it combines electrics, plumbing and, in some cases, minor building work:

• Site visit and sizing. The home, expected use and emission system (radiators, underfloor heating or fan coils) are assessed to choose the right unit power.
• Outdoor unit location. It needs well-ventilated space and, under noise regulations, a certain distance from neighbouring homes' facades.
• Plumbing work. Connecting the water circuit, installing or adapting the emission system, and fitting the hot water tank where the project calls for one.
• Commissioning. Setting the heat pump's parameters, checking pressures and flow rates, and configuring the controls.
• Visit documentation. Photos of the unit, its data plate and the finished installation, with a signed work report.

Aerothermal and an existing hot water tank

Switching to aerothermal doesn't always mean replacing the whole hot water system straight away: in some cases the heat pump can be integrated with an existing storage tank, using it as a buffer, while in others a dedicated tank designed to work with a heat pump is needed. Which option makes sense is decided at the site visit, based on the condition and capacity of the equipment already in place.

What to consider before installing

Before choosing a unit, three things are worth checking: the space available for the outdoor unit, the home's insulation (a poorly insulated home needs more power and performs worse with any system), and the actual pattern of use — a seasonal second home is a different case from a home lived in year-round.

How to judge an aerothermal installation

Rather than focusing only on the brand of the unit, it's worth looking at how the installation itself is done: whether the sizing is based on real data from the home rather than a rough guess, whether the visit is documented with photos and a work report, and whether you're given a clear explanation of what emission system the chosen unit needs. Good initial sizing is what most affects how well the heat pump performs over the years.

Once installed, a heat pump needs its own regular maintenance, with a few extra points on the plumbing side that a conventional split doesn't have.