The term “weather” refers to all the influences that make up the weather pattern at a specific place at a specific time: sun, wind and water, as rain or snow, light and air. In order to reliably protect roofs and walls from freezing cold, rain and snow, windows and doors absolutely have to form a seal when closed. This is the only way to keep bad weather out – and cosy warmth in.
Steel profile system also provide a sealing effect in the event of wind load
Windows, doors and façades consisting of steel profile systems also reliably withstand the pressure of the wind in the event of stormy weather. The wind load that can be expected depends first and foremost on the location of the building – experience has shown that it is stormier near the coast than inland. Germany can be divided into four wind zones with different base wind speeds (wind zone 1: base wind speed 22.5 m/s, 2: 25.0 m/s, 3: 27.5 m/s, 4: 30.0 m/s). However, wind load is also a factor that needs to be considered in the case of high-rise buildings, because: the higher a window is installed in the building and the higher the wind load zone classification, the greater the resistance to wind loads, driving rain and draughts must be.
Tightness of steel profile systems against water and driving rain
Windows, doors and façades consisting of steel profile systems must be watertight – regardless of whether it is just lightly drizzling or whether a storm is driving the rain at full force against the façade. The tightness of steel-profile curtain walls against driving rain is classified according to DIN EN 12154. The tightness of windows and doors against driving rain is classified according to DIN EN 12208 and tested according to DIN EN 1027. There are two different methods for the test: Method A is used for doors and windows that are fully exposed to the weather. Method B is used for building parts that are protected from the rain by canopies or balconies.
The measure of air permeability: the Q-value
Gaps around windows and doors produce draughts not only in the event of wind, but also during the colder months when the air is calm due to the natural exchange of cold and warm air. These draughts are inextricably linked with the loss of precious heat, which escapes through the gaps. Only tightly closing windows and doors ensure consistent heat insulation, which makes the Q-value described in DIN EN 12207 an important thermal insulation value for the requirements of the Building Energy Act (GEG 2020). As with the U-value, the lower the Q-value the better.
Steel profile systems produce the best results
The air permeability of curtain walls is classified according to DIN EN 12152. The thermally insulated façade systems for mullion-transom structures – Jansen VISS, VISS Basic, VISS RC and VISS SG – achieve the best possible Q-value with ‘AE’. The thermally insulating door and window systems for external applications have been put in the best class – class 4.
Build safely and in line with standards with steel profile systems
At our test centre in Oberriet, Switzerland, we can test windows, doors and façades consisting of steel profile systems with regard to wind load, tightness against water/driving rain and air permeability. This functional test enables us to ensure in advance that the planned construction reliably satisfies the requirements imposed on it. This means that our clients can reliably plan ahead, thus cutting planning time.