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Air inlets are essential components of mechanical (MEV), hybrid and natural ventilation systems. Their installation must be perfectly mastered to guaranty optimal functioning.

How to install an air inlet in the case of an MEV (Mechanical Extract Ventilation)?


Proper ventilation is provided by air inlets installed in the dry rooms (bedrooms, offices and living room) which allow the introduction of fresh air into the dwelling, and exhaust units which extract the stale air, installed in the wet rooms (kitchen, bathroom and toilets).

Depending on the configuration of the dwelling, the air inlets can be installed on window frames, on roller shutter cases or through the wall.

The installation of air inlets for MEV may be regulated, depending on the country concerned.

In France, for example, Article 4, amended on 28 October 1983, imposes minimum flow rates to be respected in the case of a humidity-controlled MEV installation:

Number of dry rooms 1 2 3 4 5 6 7
Minimum total flow in m3/h 10 10 15 20 25 30 35


The MEV air inlets are thus selected and distributed throughout the dry rooms to respect the regulation.


Installation of air inlets on window frames

The MEV air intake device consists of a canopy and an air inlet.

The canopy prevents water penetrating the dwelling. The outside canopy must be fixed in such a way as to ensure this watertightness.

The slot realisation is very important as only a conform hole will ensure the right airflow of the air inlet. The major points relative to the slot drilling process are going to be explained below in this article.

The shutters of the air inlet must be facing upwards to avoid uncomfortable draughts. If the window is too close to the ceiling or reveal, it is possible to add a spacer to direct the flow of air horizontally.


The air inlet slot installation

The slot must be done by the window manufacturer. The aeraulic and acoustic characteristics of the MEV air inlets depend on the size of the slot (refer to the product specifications for the dimensions of the slot associated with the products). The slot must be drilled at the top and centre of the frame so that the air inlet is centred on the window.


Slot dimensions

Most of Aereco air inlets for windows require the following slot, which guarantees the indicated airflow under the pressure reference (no air section reduction with this slot). Made of two parts, this slot is recommended to keep the rigidity of the window. Some other slots can also be realised; dimensions are precised in the technical data sheets.

General recommendations

  • Be sure that the slot is continuous between the canopy and the air inlet, without size reduction, so that the air section is kept along the hole (no airflow reduction)
  • Some windows may require additional sleeve to ensure the continuity of the slot between the canopy and the air inlet. Aereco offers a specific accessory (E-TFR)
  • Respect the slot dimensions indicated in the installation instruction of the air inlet to guarantee the airflow
  • It is recommended to inform the occupants that the air inlets should never be obstructed, even in cold period, to ensure sufficient ventilation


Type of windows

Aereco air inlets can be installed on PVC, wooden or aluminium window profiles. Most of profiles are compatible with Aereco air inlets. Overall the PVC window air inlet is not different from the wood or aluminium window air inlet.


Position of the air inlet

Slots positions must be chosen in order to prevent the window structure from weakness. Unless not possible, air inlet must always be placed on the top of the window, this for several reasons:

  • The outdoor air, cold in winter, can be progressively introduced and heated on the ceiling as the flow is introduced in the upper part of the window, thus preventing occupants from discomfort.
  • The sensitivity for humidity controlled air inlet to humidity is optimum at this place.
  • The air renewal will be better ensured in the room, as the air is often exhausted from the main room through the bottom of the door.
  • The top position prevent from water introduction, even in case of strong rain.


Slot drilling process

The slots drilling process for window air inlet depends on the type of work: during the manufacturing process of the window or on existing windows.

  • During the manufacturing process of the window:

If the window is prepared in factory the slot can easier be realised at this step, before the installation on site, through a professional drilling machine such as the one here aside:


  • On existing windows:

If the window where the air inlet must be placed already exists in the building, the slot cannot always be realised through a drilling machine. When possible, it is recommended to use a machine similar to the one used in factory (see previous paragraph). When not possible nor available, then several tools can be used to realise the slots.

Below are presented some of possible tools:

Cutting disc

Cutting disc





Portable drilling machine

Portable drilling machine


Process for slot drilling and inlet + canopy installation on existing window:

  1. Drill a slot in the highest part of the window to the dimensions specified in the installation instruction delivered with the product. According to the type of window the slot can be realised on the mobile or on the fix part of the window.
  2. Fix the back-plate using screws (some air inlets are directly fixed, without any backplate).
  3. Clip the air inlet on its back-plate. Make sure that the air inlet is well stuck to the window, without space to avoid noise and airflow leakage.
  4. Fix the canopy on the window (outdoor side) using screws. According to the type of window it can be on the mobile or on the fix part of the window.



Views of a standard slot realised on the mobile part (air inlet) and on the fix part (canopy) on a PVC window:


Examples of slots on various profiles:

Wooden profile PVC profile
Wooden profile:
Air inlet (left) and canopy (right)
installed on the mobile part.
PVC profile:
Air inlet (left) installed on the mobile part.
Canopy (right) installed on the fix part.



Installation of MEV air inlets on roller shutter cases

A canopy is not necessary for the installation of this type of air inlet. The leaks to the outside in the shutter case are used to provide fresh incoming air and it allows the device to be sealed.

The slot must be done by a professional on the internal vertical face of the rolling shutter case (refer to EAH² product specifications for the dimensions of the slot). The cut-out should extend through the insulation and open out into the shutter case. A sleeve is available as an accessory to prevent side air leakage through the cells of the roller shutter case.


Wall mounted installation of MEV air inlets

The EHT wall air inlet unit consists of an air inlet, a cylindrical tube and a canopy.

The air inlet is installed in the upper part of a wall so as to avoid draughts that disturb the occupant and to promote good mixing of the air in the room.

A circular hole is drilled on the façade. The air inlet is fixed on a Ø100 mm wall duct. There is also a version to cover Ø125 mm holes. The canopy is placed outside.



Once the installation is in place, it is necessary to verify that there are undercuts below doors (free 2 cm passage at the bottom of the door) so that the flow of air can pass from the dry rooms to wet rooms.



Regular maintenance (dust removal) is recommended to maintain a good air quality and ensure air flow. If the air inlets are not cleaned regularly, they may become dirty and thus reduce the performance of the MEV.

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