How does a Ventilated Facade work?
The system is based on the basic principal of the, "Chimney Effect", obtained by leaving an air gap between the cladding material and the perimeter wall of the building. The change in the air density inside the gap, due to the heat radiated by the outer covering, forces the air to move upwards and triggers a flow of natural ventilation from the bottom to the top.
This movement of air has a negligible effect in winter when a minimal amount of sunlight reaches the facade, but its affect is significant in the summer. Part of the cladding materials thermal radiation is reflected back towards the outside. The amount that penetrated the air gap is largely eliminated by the constant flow of air. This constant flow of air also helps eliminate humidity.
The ventilated facade overcomes all the lifetime constrains, such as its own weight, suspended loads, external ambient shock, wind loading, deformation in the support structure, temperature or humidity variation, solar radiation, chemical and atmospheric agents.
A rainscreen facade – often called a ventilated facade – does not try to seal the exterior of a building with a physical barrier to water. This is unlike many other facade systems, which depend on weather-barrier walls created using fitted joints and liberal applications of caulk. Such barrier-wall systems require significant effort to construct and maintain. Instead, rainscreen facades mount a semi-open screen some distance from a building that allows a little water in, but only as far as the back surface of the screen. Between this outer layer and the inner building shell sits an envelope of air.
The open joints of ventilated/rainscreen facades allow air to flow freely into and out of this envelope area. The unrestricted air movement produces three very useful benefits:
• First, the flow eliminates pressure differences that would tend to blow water further in. This means little if any water makes it across the air gap to reach the inner shell.
• Second, the air flow dries any moisture within the envelope area, such as rain that might be trickling down the back of the outer shield.
• Third, the air envelope acts as an insulating barrier by minimizing thermal bridges and preventing heat buildup within the envelope.
The result is a more sustainable, functional facade that does not require sacrifices in design.
Energy Savings – ventilated facade systems reduce the thermal flow through the building envelope, allowing for an energy savings of up to 30%.
Thermal Stability - Continuous insulation improves thermal performance by reducing bridging and thermal loads on the surface.
Cost-effective installation - The simple metal support structure is lightweight, modular and assembled completely dry, cutting the time needed to fit it on site and making it much more cost effective than traditional installation. The lighter weight of the cladding material also reduces time and labor costs.
Ease of maintenance - Although the cladding layer is made using hardwearing materials with exceptional technical specifications, the substructure has a modular design so that each individual plate can be replaced immediately should it be damaged.
Sound Insulation – Ventilated facades increase the soundproofing power of exterior walls. If we compare the Rw of typical wall construction and the same wall covered with continuous out facing insulation, we see an improvement in its soundproofing ability by up to 10-15 dB. The multiple layers of the system help block different sound frequencies and the continuous insulation eliminates acoustic bridging.
Improved Looks - the cladding layer is usually added by attaching plates made of high-tech porcelain stoneware, terracotta and metal panels. There are countless possibilities for customizing the final solution. This ultimately stimulates the creativity of designers and architects, who are often asked to lift the appeal and identity of new buildings or revitalize buildings about to be refurbished.