The choice between a centralized or decentralized Mechanical Ventilation System (VMC) depends on various factors, including the characteristics of the building, the type of use, and the occupants’ needs.
Here are some of the main criteria that a designer or installing company must consider.
- Building Size and Use
Large areas: The centralized VMC is ideal for large buildings, for structures that host many people such as shopping malls, hospitals, etc., or for homes with multiple rooms. This system uses a main unit that distributes air through a duct system, ensuring uniform ventilation throughout all rooms.
Single rooms or small buildings: The decentralized VMC (also known as “point-based”) is more suitable for small to medium-sized buildings, for the renovation of single rooms, or for environments where it is not possible to carry out masonry work. These systems do not require ducts but are installed directly on perimeter walls, offering a simpler and less invasive solution. - Building Type
New constructions: The centralized VMC is often the preferred choice in new buildings, as ducts and units can be integrated into the design from the start, reducing installation costs.
Renovations: In the case of renovations, the decentralized VMC can be more cost-effective and less invasive, as it does not require extensive masonry work for duct installation. - Energy Efficiency to Achieve
Centralized VMC: It is generally more energy-efficient, as it can include high-performance heat recovery systems, reducing energy loss and improving overall efficiency.
Decentralized VMC: Although less efficient than centralized systems, modern decentralized systems with heat recovery can still offer good levels of energy efficiency. - Installation and Maintenance Costs
The centralized VMC may have higher initial installation costs due to the ductwork installation. Maintenance is more complex, as it must be carried out by qualified personnel both on the unit and for cleaning the ducts and supply and return grilles.
For decentralized VMC systems, installation costs are generally lower, as there is no need for ductwork installation. Maintenance is simpler, as it only involves cleaning the filter, which, adhering to safety standards, can be done by private individuals as well. - Air Quality Control and Management
The centralized VMC offers uniform air quality control throughout the building. It can be integrated with automated systems that monitor and adjust ventilation based on CO2 levels, humidity, and other variables.
The decentralized VMC provides more direct and localized control, allowing the ventilation to be adjusted based on the specific needs of each room. It is ideal for those who want independent control in different areas of the building. - Aesthetics and Architectural Impact
A centralized VMC system requires space for ducts and the central unit, which can affect the interior design of the building. However, once installed, the system is generally less visible.
Decentralized VMC units do not require significant modifications inside the building. They can be a more discreet solution in terms of internal structural changes. - Flexibility and Scalability
Centralized VMC: It is less flexible in terms of expansion and future modifications, as it would require interventions on the ducts.
Decentralized VMC: It offers greater flexibility for adding or modifying units based on future needs, without significant structural interventions.
We have seen how many different criteria contribute to the choice of the ideal solution. Opting for a centralized or decentralized VMC system depends on a careful evaluation of the building’s specifics, ventilation needs, costs, and potential future developments. Each solution has its advantages and disadvantages, and the decision should be made in collaboration with a professional in the field to ensure the best possible result.
If you are an installer and need support in choosing the ideal VMC for a complex system, you can contact us here.
Discover here the wide range of VMCs by Fantini Cosmi
