Apartment ventilation: clear advice and local installation

An apartment places its own demands on ventilation. The space is often more compact, you share walls and floors with neighbors, and issues like moisture, cooking odors or sound transmission require a thoughtful approach. Without a good ventilation system, moisture accumulates in the kitchen and bathroom, risking mold and keeping the air heavy. In Flanders, where many apartment buildings date from the 1960s and 1970s, a modern ventilation solution is often necessary to live comfortably and healthily.

Different ventilation systems at a glance

Not every system fits an apartment equally well. An overview of the main types:

• System A: Natural supply via grilles, natural exhaust via chimneys. Not very suitable for apartments because it is highly dependent on wind and temperature differences, difficult to regulate.
• System B: Mechanical supply, natural exhaust. Limited in apartments; the intake of fresh air is audible and takes up extra space.
• System C: Natural supply, mechanical exhaust. Commonly found in apartments: a central extraction fan removes moist air from kitchen, bathroom and toilet. Fresh air comes in through grilles. Affordable and easy to integrate into existing situations.
• System D: Mechanical supply and exhaust, with heat recovery. The best choice for new builds or major renovations. It provides balanced ventilation, saves energy and filters incoming air. In an apartment, however, it requires ductwork, which is not always feasible with existing ceilings.

In collective residential buildings you also encounter collective ventilation: one central system for multiple residential units, with decentralized control per apartment. This requires coordination with the homeowners' association (VvE), but offers economies of scale and a stable indoor climate.

Ventilation in existing apartments: what to look out for?

When renovating or replacing an old system, practical limitations come into play. Often there are no provisions for ducts across multiple floors. System C is then the least invasive solution because it only requires an exhaust duct per wet room. Sometimes you can even connect to an existing duct. If you still want the comfort benefits of balanced ventilation (system D), it's best to check whether compact decentralized units with heat recovery per room are possible. Our technicians always come to inspect on site first before making a proposal.

What does a ventilation system for an apartment cost?

The price is determined by the type of system, the size of the apartment and the complexity of the installation. A simple system C for a small apartment can already be installed starting from €1500, while a complete system D with heat recovery can quickly cost between €4000 and €7000. Additional work such as installing ducts may sometimes be added. Always request a free assessment for a concrete price tailored to your apartment. Then you'll have clarity immediately without surprises.

Ventilating yourself? These are the pitfalls

Simply hanging a duct fan or omitting a window grille seems cost-saving, but often leads to problems: negative pressure, noise transmission from fans that are not suitable for residential buildings, or insufficient air renewal. DIY solutions rarely meet Flemish ventilation standards. With a professionally installed system, you are assured of a healthy indoor climate and proper functioning.