What is aerothermal and how does it work?
Aerothermal is a climate control system based on a heat pump that extracts thermal energy from outdoor air to generate heating, cooling and domestic hot water (DHW). Unlike a conventional boiler that burns fuel, a heat pump moves heat from one place to another, consuming only electricity. For every kW of electricity consumed, it generates between 3 and 5 kW of useful heat.
The physical principle: why does it work?
- Refrigerant circulates through the outdoor unit and absorbs heat from the ambient air, even at −15 °C.
- An electric compressor increases the pressure and temperature of the refrigerant.
- Thermal energy is transferred to the indoor water circuit (heating, DHW).
- The refrigerant cools, decompresses and repeats the cycle.
Air-to-air vs air-to-water aerothermal
| Feature | Air-to-Air (Split) | Air-to-Water (Inverter) |
|---|---|---|
| Heat distribution | By air (indoor units) | By water (underfloor heating, fan coils) |
| DHW included | No | Yes, with storage tank |
| Heating efficiency | COP 3.0–4.0 | COP 4.0–5.0 with underfloor heating |
| Cooling | Yes, fast and efficient | Yes (cold floor or fan coils) |
| Ideal application | Individual rooms, commercial | Complete homes, new builds |
COP and SCOP: how is real efficiency measured?
| System | Indicative SCOP | Relative cost per useful kWh |
|---|---|---|
| Heating oil boiler (92%) | 0.92 | High |
| Natural gas boiler (95%) | 0.95 | Medium-High |
| Electric resistance | 1.0 | Very high |
| Air-to-air split inverter | 3.0–4.0 | Low |
| Aerothermal + underfloor heating | 3.5–4.8 | Very low |
Official Installers in Alt Empordà
How much does aerothermal installation cost?
| Installation type | Approx. area | Indicative cost |
|---|---|---|
| Aerothermal + DHW (no heating) | — | €6,000 – 9,000 |
| Aerothermal + fan coils (3–4 zones) | 80–150 m² | €10,000 – 16,000 |
| Aerothermal + underfloor heating (new build) | 100–180 m² | €14,000 – 23,000 |
| Aerothermal + underfloor heating (renovation) | 100–180 m² | €18,000 – 30,000 |
Indicative prices. Request a free personalised quote.
Available grants in Catalonia (2025)
- PREE 5000 (IDAE): up to 40% of installation cost for existing homes.
- Next Generation EU (PRTR): state grants managed by ICAEN in Catalonia.
- Income tax deduction: 20–40% tax deduction for energy efficiency works.
- Municipal grants: Figueres, Roses, Castelló d'Empúries and other municipalities offer additional bonuses.
Frequently asked questions about aerothermal
Does aerothermal work well in cold weather in Alt Empordà?
Yes. Daikin, Mitsubishi Electric (Hyper Heating), Panasonic, Vaillant and De Dietrich units operate efficiently down to −15 °C and below. In Alt Empordà, temperatures rarely fall below −5 °C, so performance is excellent all year round.
Can one system both heat and cool the house?
Yes. The heat pump reverses the refrigerant cycle to switch between heating and cooling. With underfloor heating you get passive cooling in summer; with fan coils, active zone cooling.
Is annual servicing required like a boiler?
No. Aerothermal has no combustion. A technical check every 2–3 years is recommended. Far less maintenance and far lower cost than a heating oil boiler.