Mechanical exhaust ventilation Systems

May 29, 2017
Ventilation is mainly used to

icone_system_ventilation_hybride_V2Choosing the appropriate ventilation technique is essential to attaining the performance objectives set for a project, whether in a renovation or in a new building.

The right technique depends on the targets (lower heating costs, better air quality, reduced running costs, simplicity of maintenance, etc.) but depends more specifically on the environment. This is particularly true of renovations, since the technique must be adapted to the existing architecture.

Discover here a selection of the commonest techniques that can be implemented with Aereco ventilation systems:

Hybrid ventilation, collective treatment for apartments

A cross between natural ventilation and mechanical exhaust ventilation, hybrid ventilation is a modern concept that uses the components and dimensioning of the passive stack ventilation ducts coupled to non-permanent low-pressure mechanical assistance.
The mechanical assistance is used only when the natural forces are not sufficient to ensure the required airflow. It is started up automatically, and can be activated by a temperature sensor, a pressure controller, or even a wind gauge.
The fresh air is admitted by humidity sensitive air inlets in the main rooms (bedrooms and living rooms); the stale air is evacuated through the wet rooms (toilets, bathroom, kitchen) through demand controlled exhaust units. These components control the airflows according to the needs of each room.

Hybrid ventilation combines the advantages of easy maintenance, energy savings, acoustics, and reliability of passive stack ventilation with the aeraulic performance of mechanical ventilation.

Mechanical exhaust ventilation, collective treatment for apartments

3_schema_ventilation_hybride_visuelIn collective mechanical exhaust ventilation, the air in a building is renewed by a fan, installed in the roof or other convenient outside location.
In demand controlled ventilation, the air extracted through the exhaust units of the wet rooms determines the air renewal of the entire dwelling.

The humidity sensitive air inlets then distribute the new air according to the needs of each main room.

The demand controlled exhaust units distribute the airflow generated by the fan according to the needs of each wet room, in each dwelling.

Thus rooms, or dwellings, with high new air requirements induce more airflow than empty ones.

Mechanical exhaust ventilation, individual treatment for apartments or houses

In this case, the fan is placed inside the dwelling. This treatment is applicable to individual houses as well as apartments.

Placing the fan inside the dwelling has the advantage of making it directly accessible, a welcome advantage when it comes to maintenance.

As with collective mechanical exhaust ventilation, the air in the dwelling is renewed by a fan.

1_schema_ventilation_naturelle_visuelIn demand controlled ventilation, the air extracted though theexhaust units of the wet rooms determines the renewal of air in the entire dwelling. Humidity sensitive air inlets then distribute the new air according to the needs of each main room.

The demand controlled exhaust units distribute the airflow generated by the fan according to the needs of each wet room.

Thus rooms with high new air requirements induce more airflow than empty rooms.

Natural ventilation, collective or individual housing

In both individual housing and collective housing, natural ventilation exploits the natural forces (wind and stack effect) to renew the air within the dwellings.

These forces create a pressure in the air duct that starts air circulation from the inside of the dwelling towards the air duct and then outside.

The air is exhausted through the wet rooms via exhaust units, and this induces an admission of fresh air through air inlets situated in main rooms.

Depending upon natural forces (wind and stack effect), the natural ventilation may be random: it is therefore necessary to control it.

The humidity sensitive system, while measuring the humidity rate to drive the necessary airflow, gives an appropriated answer to the variability of the natural forces as it allows to compensate automatically the variation of stack effect, especially in winter.

In addition to its energy saving attributes (no exhaust fan) the first qualities of this system are acoustics (low air speeds) and simplicity of maintenance.
The pressures available in natural ventilation are from 5 to 15 Pa at the units, depending on building height and climatic conditions.

Heat recovery ventilation, individual treatment for houses and apartments

The principle behind heat recovery ventilation is to supply fresh air and exhaust stale air by a mechanical process, using double ductwork connected to a central unit that includes a heat exchanger to pre-heat the fresh air. Aereco has implemented this principle in an innovative system that controls airflows room-by-room, according to their specific needs: the DXR.

Source: www.aereco.com
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