Invisible ventilation:
4 legal ways to install a breezer or recuperator in a residential complex with strict restrictions on damaging the facade Automatic translate

Modern comfort- and business-class residential complexes often present new residents with a difficult choice. On the one hand, sealed double-glazed windows and high-quality insulation turn an apartment into a thermos, where, without forced ventilation, carbon dioxide levels rapidly rise. On the other hand, management companies strictly regulate any interventions in the building’s exterior. Facades made of porcelain stoneware, clinker, or composite panels are considered sacrosanct, and standard installation of supply ventilation becomes impossible due to the threat of fines or the loss of the developer’s warranty.

The problem is exacerbated by the design features of ventilated facades. Between the exterior tiles and the load-bearing wall, there is a layer of insulation and an air gap. Unprofessional intervention can disrupt the building’s thermal envelope, leading to freezing of the walls and condensation. Apartment owners are forced to seek engineering solutions that will ensure a supply of fresh air while remaining invisible to regulatory authorities and preserving the integrity of the cladding.

Microclimate specialists have long developed concealed installation techniques that allow these restrictions to be legally circumvented. Engineers representing specialized organizations such as Aeros regularly face the need to integrate HVAC equipment into complex architectural forms without affecting external decorative elements. Several proven technologies exist that preserve the façade warranty and ensure adequate air exchange.

Installation in a window slope

This method is considered the most elegant solution for buildings with deep external slopes. The principle of the technology is that the air duct passes through the load-bearing wall, not perpendicular to the street, but exits through the side of the window opening. The intake grille is installed on the slope plane — a metal or plastic element that is not part of the expensive ventilated façade.

The technical implementation requires high precision. Diamond drilling is performed at a specific angle or offset to precisely reach the specified point on the slope. The main challenge here is the limited space. A standard 132 mm diameter duct may not fit into the narrow gap between the frame and the wall, so special rectangular duct adapters or smaller diameter ducts with a subsequent transition are often used.

Thermal insulation is a crucial aspect of window reveal installation. The air duct running through the wall and exiting into the window junction area must be thoroughly insulated. Otherwise, the wall will freeze in this area in winter, and mold will appear on the window reveals inside the apartment. With this method, the external grille is painted to match the window frame or reveal, making it virtually invisible even from close range. This structure is impossible to see from the ground.

Concealed installation through the air conditioner basket

Most modern residential complexes are equipped with special baskets or technical balconies for external air conditioner units. These areas are already perforated or have decorative slats for air flow. This is the ideal location for a breezer air intake. If the apartment has access to such a basket, drilling into the wall is done in an area hidden behind the external unit of the split-system.

The air duct is routed directly behind the basket. The external grille is mounted on the wall, but is visually obscured by the air conditioner housing and the decorative screen of the façade basket. The management company rarely objects to such solutions, as the building’s appearance remains unchanged: the façade remains clean, and the utility opening is located in the area designated for utility lines.

When arranging the unit in this manner, airflow must be considered. If the air conditioner’s external unit is used for heating or intensive cooling, its exhaust air must not enter directly into the breezer’s air intake. Engineers address this by separating the units vertically or installing guide screens. It is also necessary to ensure that the breezer’s grille is accessible for periodic cleaning of poplar fluff and urban dust, at least with the use of rope access.

Painting and adaptation to the facade

In some cases, management companies allow direct drilling into the façade, but impose strict visual requirements. The principle of mimicry is at work here. If the façade is covered with tiles of a specific color, the external grille of the appliance must match the color perfectly. Powder coating according to the RAL catalog is used for this purpose.

The approval process typically goes like this: the owner obtains the exact color code for the façade panels from the building’s chief engineer or provides a sample for computer color matching. The grille is painted at the factory. When installed on a ventilated façade, an extended duct sleeve is used, which passes through the insulation and air gap, sealing against the cladding tiles.

Sometimes, more than just painting is required, a custom grille needs to be installed. For example, if the façade has a pronounced vertical texture or rustication, a standard round cap would look out of place. In such situations, custom rectangular façade outlets or flat caps are manufactured to match the geometry of the cladding. This makes the opening invisible from a distance of several meters.

Integration through glass unit replacement

In buildings with continuous panoramic glazing, load-bearing walls may be absent entirely, or access to them may be blocked by a solid glass façade. Drilling into aluminum profiles or glass is impossible. The only solution in this situation is to modify the glazing itself. This method is expensive and complex, but is the only option for skyscrapers and apartments with floor-to-ceiling windows.

Part of the glass unit (usually the upper transom or a blind side section) is replaced with a custom-made sandwich panel. An adapter for the air inlet is cut into this panel, painted to match the frame. From the outside, everything appears as part of the window structure. On the inside, the air inlet itself is attached to the panel.

This solution requires impeccable sealing and thermal insulation of the insert itself, as it will have lower thermal resistance than a multi-chamber glass unit. Furthermore, coordination with the window system manufacturer is necessary to ensure the static loads on the frame are not compromised. Aesthetically, this design looks neat if the insert is made of high-quality materials (such as enameled tempered glass — stemanite) and matches the tone of the exterior glazing of the façade.

Technical nuances of drilling

Any of the described methods requires the use of diamond drilling with water collection or dry diamond drilling with micro-impact. In residential spaces with finished finishes, the use of water is unacceptable, as it can damage wallpaper or parquet flooring. Professional equipment allows for a dust- and dirt-free hole, securing the drilling rig with a vacuum stand that leaves no marks on the walls.

Particular attention is paid to the channel’s slope. The opening should have a slope of 3-5 degrees toward the street. This prevents precipitation from entering the channel and ensures natural drainage of any condensation that may form. When installed into a slope, the channel’s geometry becomes more complex, and maintaining the slope requires a high degree of skill from the installer.

Soundproofing the duct is another often-overlooked factor. A hollow pipe in the wall acts as a resonator, transmitting street noise into the bedroom. A high-quality installation involves using sound-absorbing materials inside the duct or installing special mufflers behind the unit, if the wall thickness allows.

Following these rules allows for proper ventilation in the apartment without conflict with the management company or disrupting the architectural appearance of the prestigious building. Clean air becomes available without compromising aesthetics or legality.