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A Holistic View on Ventilated Façade Systems

By: Reeshika Rai, Design2Occupancy Services LLP

A ventilated façade system is a robust, multi-layer system with a ventilated air gap in between layers. The layers consist of, the cladding of the external wall, and rear insulation material. The layers, when assembled together, leave an air gap. The function of this air gap gives the pivotal benefit to this façade system, in terms of energy savings, aesthetical durability and external noise reflection in a building; for the air gap acts as a chimney and helps in reducing heat absorption in the building during summers, and retains heat inside the building while in winters, creating a “chimney effect”, which ensures continuous air flow in the air gap that helps reduce the indoor temperature. Solar radiation is partially reflected by the wall cladding, the air gap and the insulating material, thereby, lowering the heating and cooling loads in a building and increasing savings on energy.

The air gap also helps in the constant elimination of surface condensation and in removing moisture from the indoors, hence, removing humidity from the interior spaces and aiding in the comfort and well-being of the occupants.

Advantages of a Ventilated Wall

Ventilated façades are good options for new buildings and as retrofits for existing ones as they are highly aesthetical; have various colours, textures and designs and are lightweight that allow easy installation and repair. Besides the aesthetic appearance and better performance standards of the materials, compared to the traditional building materials; the advantages of laying a ventilated wall in a building are many:

1. Energy Savings: The air cavity in a ventilated façade system helps in regulating heat in a building, thereby, reducing thermal bridges and decreasing cooling and heating loads by 30%.
2. Damp Protection: The ventilated façade system provides a proper thermal hygrometric building behaviour. Moisture accumulation is dispersed by the constant ventilation in the air gap, which further prevents the growth of pathologies like mold; that affect traditionally constructed external walls.
3. Sound Waterproofing: The ventilated façade system provides sound weather protection, especially from rains and water due to the air cavity that prevents seepage of water inside the system.
4. Noise Absorption: The multi-layered façade consisting of the facing, air gap and insulating material reflects external noise and reduces it by 10- 20% while enhancing the building acoustics.
5. Aesthetical and Technical Durability: A ventilated façade with porcelain or ceramic tiles for cladding makes an ideal façade system. Along with being Eco-friendly; the porcelain and ceramic tiles are light-weighted, durable, and resistant to chemicals, pollutants, dust and sunlight. In India, innovative ventilated façade systems are slowly on the rise, like the clay ventilated façade.
6. Low Maintenance: The ventilated façade system requires limited maintenance and periodic cleaning by using soap and water.

Ventilated Façade Layers

The multi-layered ventilated façade system comprises the following functional layers:

• External wall cladding (ceramic tiles, porcelain tiles, clay tiles, polymer concrete panel, etc.): Sound selection layers:
  of materials for the cladding, considering the aesthetics and quality is important in improving the building’s appearance and protecting the wall from atmospheric agents and pollution.
•  Vertical metal sub-structure and brackets (mostly of aluminium): The vertical substructure is of aluminium with steel anchoring elements.
•  Air gap
•  Insulating layer
•  Perimeter wall

Design of a Ventilated Façade System

A ventilated façade system strictly adheres to industrial design standards and hence, the design phase decision-making is crucial to avoid any future improvisations.

Before laying a ventilated façade system, it is necessary to decide on the cladding materials, the design of the façade system and the final structural plans. The installation of the system starts with layout planning and measurements. Depending upon the sizes of the slabs and the joints, intervals or spacing are measured and brackets are fastened in them.

Thermal insulation is laid and the vertical aluminium or steel sub-structure is anchored to the brackets and fixed at the measured intervals. Finally, the wall cladding is fitted to the module which leads to the formation of the air gap. Proper dimensioning of the air gap ensures effective ventilation throughout the façade.

The type of anchoring: exposed anchoring or concealed anchoring is based on the two installation systems, the horizontal installation system and the vertical installation system.

In the ventilated façade with exposed anchoring, the vertical installation system is adopted and the horizontal installation system is applied in the ventilated façade with concealed anchoring. The right choice for anchoring is based on the aesthetics of the façade and the cost aspect of the wall cladding.

Ventilated Façade with Clay Tiles – The Most Suitable For The Indian Built Environment

With the advancement in façade technology like the ventilated façade systems, there is less of a compromise on aesthetics to meet state-of-the-art quality. And by choosing sustainable envelope designs and environmentally friendly building materials like clay, the advantages are heightened. In India, clay is easily available and its being a versatile and naturally occurring building material makes it a sustainable choice. Clay tiles are highly durable, recyclable and cost-effective with good insulation properties. Clay tiles have good noise absorption properties and provide excellent soundproofing. They have a long lifespan of 50-60 years and are non-flammable, frost-proof and maintenance-free.

Conclusion

The technology behind the ventilated façade systems uncovers its holistic benefits and advantages over traditional as well as other modern façade systems. The striking feature of the ventilated façade system is the ability to use air, a renewable resource in the ventilating process. This feature makes the system what it is, a “ventilated façade”. The continuous ventilation in the air gap enables dry insulation of the walls and slabs and expels moisture from the indoors, keeping the indoor temperature at a comfortable level. The ventilated façade systems give a strong visual impact to the building and once the system is in place and installed, the working of the technology will elevate the performance of the building; by enhancing the comfort and well-being of the occupants in the building.