closed cavity façades (ccf technology)

What is a Closed Cavity Façade?

A Closed Cavity Façade (CCF) is a type of double-skin façade in which the cavity between the inner and outer glass façade is sealed. This cavity is the functional core of the system. It is kept climatically stable through controlled ventilation with dry air under slight overpressure. This prevents the ingress of moisture, dust and insects, and protects the technical components installed within the cavity.

Advantages of a Closed Cavity Façade:

  • Low-maintenance solar shades
  • Good energy efficiency
  • Effective sound insulation
  • Minimal cleaning requirements
Close-up of the ISOshade façade system, the Advanced Closed Cavity façade from façade specialist seele. View of the closed cavity and the valve.
View of an Advanced Closed Cavity façade in a version featuring an all-glass corner. The solar shades are protected within the cavity.

What challenges come with conventional CCF façades?

Climate control within the cavity
Classic CCF systems must address two key challenges: moisture regulation and pressure equalisation within the cavity. The solution involves active ventilation through a continuous supply of dry air. The defining feature of this traditional CCF approach is the sealed and controlled airspace between the glass layers, which is permanently supplied with filtered, dry air via a central system. Each unit is connected to a central air treatment system.

Disadvantages of classic CCF:

  • Complex technical infrastructure
  • Regular maintenance required for air systems and filters
  • Accumulation of fine dust and risk of fogging due to constant air exchange
  • Space required for technical rooms and redundancy of climate control units
  • Limited maintenance options
  • Active ventilation required even during transport, storage and installation
  • Continuous energy consumption due to permanent ventilation

Due to these disadvantages, façade specialist seele developed the Advanced Closed Cavity Façade (CCF), also known as the ISOshade façade system or simply the innovative Closed Cavity Façade.

How is ISOshade different from a traditional Closed Cavity Façade?

In contrast to conventional Closed Cavity Façades, ISOshade features a simplified design that eliminates the need for external ventilation systems. A specially developed pressure equalisation system regulates the climatic loads within the closed cavity. Air exchange occurs only when needed via a valve. The daily volume of exchanged air is minimal and barely measurable. As a result, there is virtually no air circulation in the cavity – a significant advantage, as this prevents particles from circulating and, for example, causing fogging.

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What are the key benefits of ISOshade?

1. Closed cavity without active ventilation

  • No connection to an external or active ventilation system
  • Protection against dirt, moisture and insects

2. Minimal air exchange

  • Extremely low and barely measurable volume of air exchange
  • Minimal air circulation within the cavity

3. High energy efficiency and user comfort

  • Reduced energy consumption
  • Improved sound insulation due to multi-layer glass construction

4. Maintenance access for solar shades

  • Easy access to solar shades via maintenance panel
  • Simple access to drive systems

5. Long service life, low operating costs

  • All materials used are tested and certified
  • Desiccants can be easily replaced
  • Climatic balance regulated through physical principles

6. Economical even in small quantities

  • No active ventilation, making the system cost-efficient even from batch size one
  • Compatible with all system manufacturers and façade systems

7. Simplified transport, storage and installation

  • No active ventilation allows for easier logistics and storage
  • Straightforward glass installation using suction equipment or as unitised façade via crane

8. Integrated sensors & building automation

  • ISOshade is designed for integration with AI-based control systems
  • Sensors monitor temperature, humidity, air pressure and light levels
  • Monitoring through sensor data

9. Compact façade element with “IGU logic”

  • ISOshade follows the same principles as an insulating glass unit – a proven system

The classic CCF remains a high-performance façade solution, though it entails greater operational effort. This is precisely where ISOshade offers a clear advantage by reducing technical complexity and replacing it with a low-maintenance, autonomously functioning system.

When is a Closed Cavity Façade with ISOshade the right choice?

  • High-rises & office buildings
    Large glazed surfaces, high energy demand and urban environments with noise exposure are ideal conditions for ISOshade.
  • University, education and research buildings
    Energy efficiency, daylight use, integrated shading, long service life and low operating costs make ISOshade suitable here.
  • Museums, cultural buildings & private residences
    Light protection, stable indoor climate and elegant façade design are key factors.
  • Healthcare sector (hospitals, clinics & laboratories)
    Easily cleanable surfaces, even indoors, and optimal daylight control are crucial.
  • Construction projects in wind-exposed locations
    Solar shades integrated into the cavity are protected from wind and weather conditions.

best practices ISOshade