ComfortSuper-cooled interiors and over-heated rooms are both uncomfortable environments to be in.
Design with solar glassThe trend today is towards design-oriented façades, which require new designs in solar control glass.
EcologyWherever energy is saved – whether by reducing the amount of cooling power used or artificial lighting - the environment also benefits as a result.
EconomyLarge window and façade surfaces allow plenty of light to penetrate deep into a building’s interior, thereby avoiding excessive use of artificial lighting.
Our product: SunGuardRegardless of what the building’s architectural or building physical requirements are, the broad SunGuard® glass range can provide an optimum transparent solution.
Sun protection in summerModern insulated glass allows short-wave solar radiation to pass through without hindrance, but the majority of long-wave heat radiation is reflected back to the interior.
Sun protection in summer
Modern insulated glass allows short-wave solar radiation to pass through without hindrance, but the majority of long-wave heat radiation is reflected back to the interior.
This results in solar heat gain in the cold seasons. ln summer, however, this solar radiation can result in overheating.
In addition to other energy sources (see figure below), the position and size of the glazing are critical. In general, windows or façades with large glazed areas that face East, West and particularly the South, should be equipped with suitable sun protection glazing.
Specific requirements need to be met to prevent overheating that can result from large glass surfaces, starting with the solar input factor S.
In general, the following rule applies according to DIN 4108:
S existing ≤ S admissable
The admissible solar input factor results from the proportional input factors.
S admiss. = S1 + S2 + S3 + S4 + S5 + S6
The proportional input factors depend on:
S1: utilisation of the building (residential/commercial, climate zone, type of construction, night cooling) – see DIN 4108-2, table 8.
S2: percentage of window area.
S3: solar control glass.
S4: glazing slope.
S5: glazing orientation.
S6: passive building cooling
The existing solar input factor results from the following equation:
AW,j: glazed area in m²
AG: ground area of the room in m²
gtot,j: (total) solar factor including mechanical shading:
- EN ISO 52022-1
- EN ISO 52022-2
- based on EN 410
- manufacturer statements
Determination of gtot is carried out using the following equation:
g tot = g x Fc
g: solar factor of the glazing
Fc: reduction ratio for shading devices
The generalised reduction ratio FC for fixed installed shading systems can be taken from DIN 4108-2, table 7.
A detailed method for the determination of gtot is available according to EN ISO 52022-2. This method considers the specific physical properties and the interactions of a defined shading and a defined glazing. The calculations are to be carried out using special software tools.
The Guardian Technical Advisory Centre can support with related calculations on request.