Building Construction Physics
air-lux® Windows and Facade Systems
Air conditioning concept for buildings
The thermal-technical requirements for buildings are essentially determined by the characteristics of the building components. A combination of patented air-lux® profiles with multiple glazing and a unique patented pneumatic air-lux® sealing system will ensure highly efficient thermal insulation and an optimum warmth yield. The innovative air-lux® system already meets the energy standards of the future, and is thus an excellent component of sustainable and modern building construction.
Minergie® Standard or greater is the state-of-the-art of technology at air-lux®, and corresponds with ecological as well as economic aspects. Large surfaced sliding glazing by air-lux® is thus a highly efficient heat insulating building construction component.
Heat Insulation
U parameter, heat permeability
The U parameter (heat permeability coefficient: W/m²K) is the unit for measuring heat loss and indicates the volume of energy that flows through the surface of 1m² of a building component when the ambient temperatures on adjacent surfaces differ. The lower the U parameter, the higher the heat insulation. Energy is transmitted from the room air to the internal pane, warming the insulation glazing of the pane on the roomspace side. The exchange of energy is mainly the result of long-wave infra-red radiation. In addition, there is a transmission of heat and a minimum convection in the interior space of the pane, which causes the energy to flow from the internal to the external pane. These three mechanisms lead to the exterior pane warming up. This then releases energy by conduction, radiation and convection to the external ambient air. The U parameter is therefore a unit for the heat insulation capability of an enclosed construction.
The characteristics of insulating glass with functional layerings:
- Reduction in energy cost by high heat insulation (U parameter)
- Maximum light transmission up to 75% of a sunlit roomspace and living comfort
- Optimum exploitation of sunlight energy by various sunlight protection coatings (g parameter)
- Depending on the air conditioning concept of a building, various U and g parameters can be combined.
- Heat insulation and sunlight insulation coatings can be combined with safety and noise insulation functions
- Ideal for passive and low-energy buildings
| Element Dimensions | U-Parameter Glazing | U-Param. per Element | |||
|---|---|---|---|---|---|---|
| Position | Width (mm) | Height (mm) | Surface Area (m²) | Sliding Casement (W/m²K) | Fixed Pane (W/m²K) | (W/m²K) |
| 1 | 5.000 | 3.000 | 15 | 0.70 | 0.70 | 0.99 |
| 2 | 7.000 | 3.000 | 21 | 0.70 | 0.70 | 0.95 |
| 3 | 9.000 | 3.000 | 27 | 0.70 | 0.70 | 0.93 |
| 4 | 5.000 | 3.000 | 15 | 0.60 | 0.60 | 0.90 |
| 5 | 7.000 | 3.000 | 21 | 0.60 | 0.60 | 0.86 |
| 6 | 9.000 | 3.000 | 27 | 0.60 | 0.60 | 0.84 |
| 7 | 5.000 | 3.000 | 15 | 0.50 | 0.50 | 0.81 |
| 8 | 7.000 | 3.000 | 21 | 0.50 | 0.50 | 0.77 |
| 9 | 9.000 | 3.000 | 27 | 0.50 | 0.50 | 0.75 |
| All parameters with laminated glazing edge Psi-parameter 0.067 W/m²K calculated. | ||||||
G parameter, heat exploitation
The overall heat permeability (g parameter in %) indicates how much energy from the sun’s radiation reaches the roomspace through the glazing. It is made up of two parts: the direct transmission of radiation and the secondary heat release. The secondary heat release is obtained from the fact that glass heats up as a result of sunlight radiation and then releases heat to the interior and the exterior. The higher this g parameter, the more sunlight radiation is transmitted to the interior roomspace via the glazing.
Thermic separation with the air-lux® window system
When planning large areas of glazing and facade constructions, the avoidance of heat bridges is the prerequisite for being able to provide the user with good insulation performance. Good workmanship will avoid consequential damage, such as condensation, mould, reduced insulating properties or long-term damage to the building structure.
The thermic separation with the air-lux® system is ensured by many years of development. This consists of a multi-shelled window frame profile with an internal and an exterior aluminium profile, as well as a centre profile as insulator made of a special plastic. The exterior sliding casement profile is made up of several individual profiles of aluminium and plastic, which are partially connected by traction.
The use of insulating glass with low U parameters, a heat-insulating frame edging combination system and the patented air-lux® airtight system can achieve extremely low U parameters above the MINERGIE Standard.
The illustrated isotherms were obtained under the following conditions:
Internal temperature = 20°C
External temperature = -10°C
Resistance capability against wind pressure (European Standard EN 12210) Class C4 / B4
Under conditions of statical and dynamic wind pressure, the effects of wind forces on the deformation of the window elements are tested. Permanent deformation would produce massive functional disadvantages. The air-lux® system achieves very high parameters under such test conditions. This again proves that the correct dimensioning of the profile statics is very important. air-lux® pursues the consistent 'path' between aesthetics and functional benefit. air-lux® sliding casements are designed to meet the stresses and strains.
Air permeability (European Standard EN 12207) Class 4
Air permeability is the principal measured quantity in a window system, and is ascertained by sucking and blowing effects. Losses in the sealings are associated with loss of comfort and energy. air-lux® is a 100% patented airtight system. air-lux® achieves the highest Class 4.
Driving rain leakproofness (European Standard EN 12208) Class E1500
Driving rain can be defined as vertical rainfall driven by the wind against the building. This means that rain not only hits the ground, but also vertical surfaces. The driving rain impermeability means the capability of a window-facade system to resist the entry of water in a closed and locked position, under a certain pressure. air-lux® is the only system to achieve top parameters and Class E1500 for pane sizes of over 16m². This capability is important for properties in exposed weather conditions, or with particular geographical locations, such as lake, sea and mountain regions, as well as for high-rise constructions.
Sound proofing (European Standard EN 14351-1)
The term sound proofing refers to sound reflection, which diverts airborne sound energy (e.g. exterior noise). In window construction, sound protection can be defined by special insulating glazing on a targeted basis. This implies the enlargement of the mass of the glazing, an asymmetrical superstructure or the employment of soundproofing film in the laminated-glass glazing. Although the surface proportion of the windows on a building shell can be very high, the sound proofing effect is not only achieved by the insulating glazing; the framework, the fittings and the seals between the window frame and the casement, and the jointing to the building construction have to be mutually coordinated. air-lux® again demonstrates its market positioning in this performance spectrum. Sound proofing parameters for the completed facade (window frames and glazing) of up to 43dB can be achieved.