Air-to-air heat pumps in Brussels: why they often miss out on regional grants

Every year, we receive enquiries from Brussels homeowners considering an air-to-air heat pump to heat their home, attracted by its lower installation cost compared with an air-to-water heat pump. The question that comes up almost every time: "Can I get a regional grant for this type of installation?" The answer, in the vast majority of cases, is no. And this answer is not arbitrary: it rests on a precise technical and administrative distinction, which we want to explain clearly before you commit to a project.

Air-to-air and air-to-water: two different heating logics

On paper, both systems share the same physical principle: capturing the heat present in outdoor air and releasing it inside the home. But the way this heat is distributed changes everything.

An air-to-water heat pump transfers the captured energy to a water circuit that feeds radiators, underfloor heating or fan convectors. It is therefore integrated into a hydraulic central heating system, comparable to that of a conventional boiler. It is precisely this integration into a hot water network that allows it to be considered central heating equipment within the meaning of the regulations.

An air-to-air heat pump, on the other hand, releases heated (or cooled) air directly into the room via one or more indoor units, somewhat like a reversible air conditioner. There is no water circuit, no radiators, no hydraulic distribution. From a technical standpoint, it works more like a reversible air conditioning unit than a central heating generator in the conventional sense.

This difference may seem purely technical, but it has direct administrative consequences on access to grants.

Why Brussels grants target central heating

The Brussels Region's energy grants, managed by Brussels Environment, are primarily aimed at encouraging the replacement of ageing or poorly performing central heating systems with more efficient solutions. The objective is twofold: reducing buildings' energy consumption and cutting greenhouse gas emissions linked to residential heating.

Within this logic, the equipment supported is that which replaces or complements an existing central heating system: condensing boilers, air-to-water heat pumps, geothermal heat pumps, or certain hybrid systems. An air-to-air heat pump, which does not fit into this water-based distribution architecture, generally does not fall within this framework, even though it too can heat a space effectively.

There is also a more pragmatic dimension: an air-to-air heat pump is often installed to complement existing heating, for a specific room or zone, rather than as a full replacement of the home's heating system. Regional authorities find it difficult to regulate and monitor this type of partial use, which further reinforces its exclusion from grant mechanisms.

What Brussels regulations do (and don't) say

It's important to remain cautious on this point: the conditions for regional grants change regularly, sometimes from one year to the next, and the categories of eligible equipment can be adjusted. We therefore cannot state definitively and permanently that no grant will ever exist for an air-to-air heat pump in Brussels. What we can say, however, is that the current regulatory trend clearly favours hydraulic central heating systems, and that the air-to-air heat pump remains, to this day, an exception rather than the rule within support schemes.

This is why we systematically recommend checking the conditions in force at the exact time of your project, directly on the Brussels Environment website (bruxelles-environnement.be), rather than relying on information picked up the previous year or from a neighbour who obtained a grant for a different project to yours.

Another point worth noting: certain federal grants or tax benefits, separate from Brussels regional grants, may exist for reversible air conditioning equipment or air-to-air heat pumps in certain professional contexts or comprehensive energy renovation projects. These schemes follow entirely different logics and conditions from regional energy grants, and should not be confused with them.

Cases where an air-to-air heat pump may still be considered

Even though the standard regional grant generally remains out of reach, several situations deserve to be examined on a case-by-case basis before jumping too quickly to a conclusion of total exclusion.

Multi-split air-to-air systems with a primary heating function. Certain multi-split installations, correctly sized and covering all of a home's thermal needs, may in some contexts be assessed differently by the authorities, particularly as part of comprehensive energy renovations evaluated through an EPB (energy performance of buildings) audit. This remains marginal, however, and depends heavily on the specific file.

Grants linked to comprehensive renovation. If your project is part of a large-scale energy renovation (insulation, ventilation, window replacement), certain aids calculated on the building's overall performance may exist independently of the precise nature of the heating system installed. It is then worth checking whether the air-to-air heat pump is taken into account in the overall calculation, even without a specific grant dedicated to it.

Municipalities and social operators. Certain Brussels municipalities or specific organisations occasionally offer local aid, separate from regional grants, with their own eligibility criteria. These schemes are less well known but sometimes more flexible regarding the type of equipment supported.

In all these cases, the rule remains the same: check before committing, never after installation.

How to check your project's real eligibility before committing

Before signing a quote for an air-to-air heat pump, we recommend following a few simple but essential steps.

Check the official Brussels Environment website. This is the only reliable and up-to-date source for knowing which categories of equipment are eligible for Brussels energy grants at the time of your project. Conditions, amounts and caps change regularly and may differ from one year to the next.

Ask your installer for a clear statement. A reputable, approved installer should be able to tell you, before any work begins, whether the equipment envisaged falls into the categories recognised by regional grants. If this answer remains vague or evasive, that's a signal worth taking seriously.

Never base your purchasing decision solely on the hope of a grant. An air-to-air heat pump remains an excellent investment for the thermal comfort of a specific room or space, including summer cooling, regardless of any grant. Evaluate the project on its own merits: comfort, electricity consumption, noise, maintenance, rather than on a hypothetical financial aid.

Compare with an air-to-water solution if central heating is your priority. If your main objective is to replace an ageing boiler for the whole home and benefit from regional grants, an air-to-water heat pump remains, under current regulations, the choice most consistent with existing support schemes.

Our role as an approved installer

At DPS Chauffagiste, we support Brussels homeowners in installing heat pumps, whether air-to-air or air-to-water, but also in understanding the administrative implications of their choice. Our role is not to steer you towards the easiest solution to sell, but towards the one that truly matches your heating needs, your budget and, where applicable, your eligibility for regional grants.

Before any quote, we take the time to assess with you your home's configuration, your actual needs (heating the whole home or a specific zone) and the support schemes potentially applicable to your situation. This step avoids unpleasant surprises and after-the-fact disappointments, when a grant application is refused after installation because the chosen system was not eligible.

If you're torn between an air-to-air heat pump and an air-to-water solution for your project in Brussels, feel free to contact us for a full assessment. We'll give you a clear and honest picture of the real possibilities, grants included, before you commit to either option.