« Châssis, panneaux et pompe à chaleur en une seule fois : on a eu un seul devis, un seul planning et zéro paperasse pour les primes. Le résultat est impeccable et notre facture d'énergie a chuté. On ne pensait pas que ce serait aussi simple. »
Air-to-air heat pump: heat and cool with a single unit
The easiest solution to install for heating in winter and cooling in summer. The air-to-air heat pump captures heat from the outside air and delivers it through wall-mounted splits — perfect as a supplement, in light renovations or for a living space, with no major works and no water circuit.
- 1 → 5 kW
- per indoor unit
- ~1 day
- to install, no water
- up to 4.5 kWh
- delivered / 1 kWh
What an air-to-air heat pump is really worth
The figures that matter for a quality air-to-air heat pump, installed by our teams. Concrete benchmarks, not marketing.
- Efficiency (SCOP) 3.5–4.5
The seasonal coefficient of performance shows the energy delivered per kWh consumed. A quality air-to-air heat pump returns 3.5 to 4.5 kWh of heat for 1 kWh of electricity — far more than an electric convector.
- Cooling mode (SEER) 6–8
In summer, the unit reverses and cools. Cooling efficiency (SEER) reaches 6 to 8 on the better models — summer comfort without installing a separate air conditioner.
- Sound level 19–25 dB(A)
Recent wall-mounted splits are very quiet indoors (from 19 dB(A)). The outdoor unit is positioned to limit any nuisance to neighbours, in line with the regulations.
- Heating range down to −15 °C
Modern inverter models keep heating in cold weather, down to about −15 °C. During prolonged severe cold, a supplementary heat source remains useful in poorly insulated homes.
- Configurations Mono → multi
A mono-split for one room, a multi-split (up to 5 units on a single outdoor unit) for several rooms. We size the system to the areas and orientation.
- Installation No water circuit
No radiators or pipework to redo: just a refrigerant line between the units. Installation is fast and minimally invasive, ideal for renovations.
* Indicative values for standard-range models. Real-world performance depends on the model, the sizing and the insulation of the home — confirmed during the technical survey.
Pros & cons of air-to-air
No heat pump is perfect for every project. Here, honestly, is where air-to-air excels and where another solution is a better fit.
Where it shines
- Fast, minimally invasive installationNo water circuit or structural work: often installed in a single day.
- Heating AND coolingA single unit for winter and summer, reversible at the touch of a button.
- Modest upfront investmentThe lowest entry cost of any heat pump.
- Ideal as a supplement or per roomPerfect for a veranda, an office or a poorly heated living space.
What to keep in mind
- Heat through forced airThe comfort differs from central heating with radiators or underfloor heating.
- Does not produce hot waterUnlike an air-to-water unit, it only heats the indoor air.
- Visible unitsWall-mounted splits indoors and an outdoor unit to blend in tastefully.
- More limited grantsOften less supported than air-to-water by regional grants.
Is an air-to-air heat pump right for you?
It shines where you want heat and cold quickly, without heavy works. A few cases where it stands out:
-
Living space or open-plan area
Efficiently heat and cool a living room, lounge or open space, where a single well-placed unit is enough to cover the volume.
-
Veranda, office, extension
Glazed rooms overheat in summer and struggle to heat in winter. The air-to-air heat pump solves both at once, without touching the central heating.
-
Apartment or light renovation
When redoing a water circuit is too much, a multi-split heats several rooms from a single outdoor unit — ideal in shared buildings.
For complete central heating with domestic hot water, take a look at the air-to-water heat pump. And if your land allows it, geothermal offers the best long-term efficiency.


Convectors replaced by a reversible multi-split
An apartment heated with direct electric convectors, with steep winter bills and no solution for heatwaves. We installed a 3-unit multi-split in a single day: efficient heating in winter, cooling in summer, all controlled from a smartphone.
- −45%on the heating bill
- 1 dayto install, no major works
- 3 roomson a single outdoor unit
They chose wendows
5.0/5 · 3verified reviews
« Passage du mazout à une pompe à chaleur air-eau. Chantier propre, anciens radiateurs conservés. La maison est mieux chauffée pour bien moins cher. »
« PAC air-air réversible installée avant l'été. Confort été comme hiver, et le SAV répond vite. Très satisfait du suivi. »
Air-to-air, or another heat pump?
The air-to-air heat pump excels at simplicity and cooling. Depending on whether you want hot water, central heating or the best efficiency, another type may suit you better.
| Critère | Air-to-air heat pumpVous êtes ici | Air-to-water heat pumpVoir la gamme → | GeothermalVoir la gamme → |
|---|---|---|---|
| Investment | The most affordable | €€€ — mid-range | €€€€ — the highest |
| Central heating (water) | No, forced air | Yes, radiators/underfloor | Yes, radiators/underfloor |
| Domestic hot water | No | Yes, optional | Yes, optional |
| Cooling in summer | Yes, built in | Depends on model | Passive cooling |
| Efficiency (SCOP) | 3.5–4.5 | 3.5–4.8 | 4.5–5.5 |
| Works involved | Light, ~1 day | Moderate | Heavy (drilling/loop) |
| Best for | Supplement, living space, renovation | House, complete heating | New build/heavy renovation, long term |
- vs air-to-air
Air-to-water heat pump
Complete central heating: radiators or underfloor heating, plus domestic hot water. The go-to choice for the whole house.
Compare with air-to-water → - vs air-to-air
Geothermal heat pump
The best efficiency, stable all year round thanks to the heat of the ground. A heavier investment, profitable over the long term.
Discover geothermal → - to combine
Hybrid heat pump
A heat pump paired with your existing boiler: the heat pump handles everyday needs, the boiler takes over in severe cold.
See hybrid → - grants
Grants & VAT 2026
Wallonia or Brussels grant, reduced VAT: what you are entitled to depending on your region and income.
Calculate my grants → - budget
Price & profitability
Installed price ranges and payback times by heat pump type and your current consumption.
See the prices → - ↑ category
All heat pumps
An overview of our heat pump solutions in Belgium: types, sizing, grants and installation gathered on one page.
Back to the heat pump guide →
How much does an air-to-air heat pump cost?
The price depends on the number of indoor units, the output and whether it is a mono or multi-split setup. Here are some benchmarks for installed equipment.
See heat pump prices & grants in detail →* Indicative ranges for installed equipment, excluding specific configurations. A costed estimate is provided with your free quote.
- Mono-split from €1,9001 unit installed, living space
- Multi-split €3,000–6,0002 to 4 units, a single outdoor unit
- Wallonia grant up to €1,000depending on income and region
- Reduced VAT 6%in renovation (home > 10 years)
Your questions about air-to-air
Does an air-to-air heat pump really heat in a Belgian winter? +
Yes. Recent inverter models heat down to about −15 °C outside. In Belgium, they cover most of the season; in a poorly insulated home or during prolonged severe cold, a small supplementary source can remain useful.
What is the difference from a regular air conditioner? +
Technically, a reversible air-to-air heat pump is an air conditioner capable of heating efficiently. The difference lies in heating-oriented sizing and control: we prioritise heating efficiency (SCOP) as much as summer comfort.
Does it produce domestic hot water? +
No. The air-to-air heat pump only heats the air. For hot water, you need an air-to-water heat pump, a thermodynamic water heater or a dedicated tank. We guide you according to your needs.
How many indoor units do I need? +
A single well-placed unit is often enough for an open-plan living area. To heat several closed rooms, we install a multi-split (up to 5 units on a single outdoor unit). The number is decided during the survey, based on the areas and layout.
Is it noisy for the neighbours? +
The indoor units are very quiet (from 19 dB(A)). The outdoor unit is more audible: we position and orient it to comply with noise regulations and limit any nuisance to neighbours.
What grants are available for an air-to-air heat pump in Belgium? +
Grants for air-to-air are generally more limited than for air-to-water, but the 6% VAT applies in renovation (homes over ten years old) and some regional grants exist depending on your income. We check your eligibility before the quote.
Get your free air-to-air heat pump quote within 48h
Free technical survey, precise sizing, grants calculated. Describe your project in under a minute.
- Free and with no obligation
- Grants & 6% VAT handled for you
- Installed by our certified technicians