An air-to-air heat pump delivers 3 to 4 kWh of heat for every 1 kWh of electricity it uses. But the real cost hinges on the SCOP, the Belgian climate, your insulation and the price of electricity (~€0.35/kWh). Here is the maths, a worked example and how to bring the bill down.
The cost of an air-to-air heat pump is not on the label — it has to be calculated. Here are the concrete benchmarks to estimate your real consumption, no marketing spin.
The SCOP (Seasonal Coefficient of Performance) shows how many kWh of heat the pump delivers per kWh of electricity across the whole heating season. A SCOP of 4 means 4 kWh of heat for every 1 kWh paid for. This is THE number to watch — not the lab COP measured at +7 °C.
Annual consumption (kWh elec) = heating demand (kWh/yr) ÷ SCOP. Cost = elec consumption × price per kWh. Example: 8,000 kWh of demand ÷ SCOP 4 = 2,000 kWh elec × €0.35 = €700/yr. That is the core formula to remember.
A well-insulated home needs ~60 kWh/m²/yr; a poorly insulated one, up to 150 and beyond. For 120 m², that ranges from 7,200 to 18,000 kWh/yr of demand — double or half on the final bill.
The colder it gets, the harder the pump works: the COP drops towards 0 °C and falls below −5 °C. In Belgium, very cold spells stay short, but they trigger the electric backup resistance (COP of 1), which weighs on the seasonal average.
The 2026 Belgian rate hovers around €0.35/kWh all-in. Every rate change feeds straight into the heating cost: a dual-rate tariff or solar panels shift the equation considerably.
In summer, the air-to-air pump doubles as an air conditioner. Cooling also uses electricity: count on €150 to 400/yr depending on usage and the number of rooms cooled. Factor it into the total annual budget.
* Indicative values for Belgium in 2026, excluding any specific consumption profile. Real consumption depends on insulation, the set temperature and the household’s habits — refined during the survey.
A well-sized, well-used air-to-air heat pump costs little to run. Badly fitted or in a leaky home, the bill climbs. Here are both sides, no spin.
The annual cost of an air-to-air heat pump depends mainly on your home. Here are the profiles where it proves most economical to run:
With low demand (~60 kWh/m²/yr), a SCOP 4 air-to-air pump heats for €500 to 800/yr. The ideal case on the bill side.
To heat the living room or top up another system, the air-to-air pump targets the rooms in use and avoids heating empty space. Consumption stays under control.
By self-consuming solar electricity, the cost of the kWh feeding the pump drops. The heat pump + photovoltaic combo is the most cost-effective to run.
If you also want to produce your domestic hot water and feed radiators, look at the air-to-water heat pump. And to keep heating reliable in deep cold without spiking the bill, the hybrid heat pump switches over to the boiler during cold peaks.
A 140 m² house heated by electric convectors used ~9,500 kWh/yr, about €3,300. By switching to two SCOP 4.2 air-to-air units, heating consumption fell to ~2,400 kWh elec, about €840/yr — same comfort, with the heating bill cut by nearly four.
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On pure consumption, the three technologies have different profiles. Compare the SCOP, the annual cost and summer use, then open the solution that fits your project.
| Critère | Air-to-air heat pumpVous êtes ici | Air-to-water heat pumpVoir la gamme → | Hybrid heat pumpVoir la gamme → |
|---|---|---|---|
| Typical SCOP | 3.5–4.5 | 3.0–4.5 | 3.0–4.0 |
| Annual heating cost | €600–1,200 | €800–1,600 | €900–1,500 |
| Domestic hot water | No | Yes | Yes |
| Summer cooling | Yes (cooling) | Depends on model | Rarely |
| Cold-weather performance | Electric backup | Electric backup | Switches to boiler |
| Insulation needed | High | High | More forgiving |
| Ideal for | Rooms, backup, cooling | Full heating + DHW | Gas/oil renovation |
The complete page on the air-to-air heat pump: principle, installation, comfort and price. The starting point before digging into consumption.
All about air-to-air →Central heating + hot water via the water circuit. More versatile, it uses a little more but covers every need.
Compare with air-to-water →Heat pump + boiler that switches over during cold peaks. Consumption stays under control even when the air-to-air drops off.
Discover the hybrid →Powering the pump with your own solar electricity slashes the cost per kWh. The most cost-effective combo to run.
See photovoltaic →Regional grants and reduced VAT ease the investment. We check your eligibility and handle the paperwork.
See heat pump grants →An overview of our heat pump solutions in Belgium: air-to-air, air-to-water, hybrid, geothermal, grants and installation.
Back to the heat pump guide →Beyond the purchase, it is the running cost that matters. Here are benchmarks for annual consumption for an average Belgian home, at 2026 electricity rates.
Estimate my exact consumption →* Estimates for ~120 m² with standard demand, electricity at €0.35/kWh. The real cost depends on insulation and habits — quoted during your free survey.
The basic formula: electricity consumption (kWh/yr) = heating demand (kWh/yr) ÷ SCOP. Then multiply by the price per kWh. Example: a home with 8,000 kWh/yr of demand and a SCOP 4 pump uses 2,000 kWh of electricity, about €700 at €0.35/kWh. Your heating demand is shown on your EPC or can be estimated from the floor area and insulation level.
The COP is measured in the lab at a fixed temperature (often +7 °C) and flatters the unit. The SCOP, on the other hand, is a seasonal efficiency: it accounts for temperature variation across the whole heating season, including the cold days when the pump is less efficient. So it is the SCOP that reflects your real consumption. Aim for 4 or more.
Yes, more. The colder the outside air, the lower the COP: around 0 °C it sits near 2.5–3, and below −5 °C it can drop under 2. The electric backup resistance then takes over with an efficiency of 1. In Belgium these spells stay short, but they pull the seasonal average down.
A reversible air-to-air pump doubles as an air conditioner in summer, and that cooling uses electricity too. Depending on the number of rooms cooled and how intensively, count on an extra €150 to 400 a year. It is a line often forgotten in the annual budget, but a real one.
At equivalent performance, yes in most cases. Thanks to its efficiency of 3 to 4, an air-to-air pump uses far less final energy. Even with a more expensive electricity kWh than a gas kWh, the heating cost is often lower, especially in a well-insulated home. Against oil, the gap is usually even wider.
A few effective levers: insulate the home to cut demand, lower the set point (each degree less saves ~7%), heat only the rooms in use, service the unit and clean the filters, and above all pair the pump with solar panels to self-consume cheaper electricity. Good sizing from the start also avoids the short cycles that waste energy.
We calculate your real demand, the right SCOP and the expected annual cost for your home. Describe your project in under a minute.