If you are thinking about installing aerotermia or you already have it at home, you are probably wondering: “how much does aerothermics consume?” or “how much does aerothermics spend per month”. Although it is a system recognized for its high energy efficiency, the real consumption depends on many factors: the power of the heat pump, the COP or SCOP of the equipment, the climate zone and the insulation of the house, among others.
In this guide we explain, with easy formulas and real examples in the province of Girona, how much the aerotermia really consumes, how it compares to other systems such as gas, oil, pellets or electric radiators and what you can do to reduce costs.
In addition, we will show you real cases of customers who have changed their old boiler for aerothermal, some even combining it with the installation of solar panels to reduce the bill to a minimum.
How to calculate the power consumption of fan heaters
To find out how much your fan heater spends per month, you need three key pieces of information:
- Heat pump thermal power (kW).
- COP or SCOP (Seasonal Coefficient of Performance).
- Hours of use per day (depending on area and insulation).
Basic formula:
Consumo eléctrico (kWh/día) = Potencia térmica (kW) × Horas de uso / COP
Example:
11 kW heat pump, COP of 4, 6 h/day:
Consumo = 11 × 6 / 4 = 16,5 kWh/día
Mensual = 16,5 × 30 = 495 kWh/mes
Coste mensual = 495 × 0,15 € = 74,25 €
Table of monthly and annual consumption according to power
| Heat pump power | Monthly consumption (kWh) | Monthly expense (€) | Annual expense (€) |
|---|---|---|---|
| 8 kW | 364 | 54,6 | 655 |
| 9 kW | 405 | 60,7 | 728 |
| 10 kW | 450 | 67,5 | 810 |
| 11 kW | 495 | 74,3 | 891 |
| 12 kW | 540 | 81,0 | 972 |
| 14 kW | 630 | 94,5 | 1.134 |
| 16 kW | 720 | 108,0 | 1.296 |
Values calculated with average COP 4, use 6 h/day and electricity price 0.15 €/kWh. In well insulated houses with underfloor heating, the cost may be lower.
Comparison of annual consumption: aerothermal vs. other systems
| Heating system | Final energy consumption | Annual cost (€) | CO₂ emissions/year |
|---|---|---|---|
| Aerothermal (COP 4) | 3,000 kWh electric | 450 | 600 kg |
| Gasoil | 1,200 liters | 1.620 | 3,100 kg |
| Natural gas | 12,000 kWh gas | 720 | 2,200 kg |
| Pellets | 4 t | 1.200 | 800 kg |
| Electric radiators | 12,000 kWh | 1.800 | 2,400 kg |
Conclusions:
- Up to 75% cheaper than direct electric heating.
- Compared to diesel, the savings can exceed €1,200 per year.
- With photovoltaic self-consumptionthe real cost can go down to almost zero.
Real cases in Girona
1. Chalet in Olot (cold area)
- 180 m², aerothermal with underfloor heating + DHW.
- Actual SCOP: 3.8 → 4,868 kWh/year → 730 €/year.
- Before: diesel (2,000 liters/year = 2,700 €).
- Annual savings: ~2,000 € + free cooling in summer.
2. Apartment in Girona city (new construction, centralized system)
- 95 m², A insulation, individual meters.
- Actual SCOP: 4.4 → 1,863 kWh/year → 280 €/year.
- Before (reference): natural gas (650 €/year).
- Annual savings: ~370 €.
3. Restored farmhouse on the Costa Brava (temperate zone)
- 220 m², aerothermal + solar thermal support.
- Actual SCOP: 4.6 → 3,478 kWh/year → 522 €/year.
- Before: propane (2,300 €/year).
- Annual savings: ~1,780 €.
Monthly consumption according to surface and climate (Girona)
| Surface | Cold zone (€) | Temperate zone (€) |
|---|---|---|
| 80 m² | 57 – 63 | 38 – 44 |
| 100 m² | 69 – 78 | 45 – 53 |
| 120 m² | 84 – 95 | 54 – 63 |
| 150 m² | 105 – 117 | 68 – 75 |
| 200 m² | 138 – 157 | 90 – 102 |
Example: in Banyoles, a 120 m² house spends ~60 €/month in winter; in Vall de Camprodon, ~90 €/month.
Factors that most influence consumption
- Climate zone and outside temperature
- Costa de Girona → lower consumption.
- Pre-Pyrenees → up to +40% expenditure.
- Isolation
- Poor insulation can increase costs by 50%.
- Emitter type
- Underfloor heating: SCOP 4-4.8 → less consumption.
- Older radiators: SCOP 1.8-2.5 → more consumption.
- Equipment configuration and power
- Well-adjusted climate curve = constant savings.
- Usage habits
- Each extra degree in winter = +7% expense.
- Maintenance
- Clean filters, correct pressure and no leaks.
In the province of Girona, aerothermal energy can be the most efficient option for heating, cooling and DHW, with savings ranging from 30% to 75% compared to other systems. And if combined with solar panels, the monthly cost can drop to less than half.
If you want to know if your house is a good candidate for this system, we can prepare a free aerothermal study adapted to your home, consumption and location.