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Project definition: Energy costs
Over the past few years, energy costs have risen considerably, not least due to the "green taxes" that have been introduced. Having said that, we are also now more aware of environmental issues and more careful in how we use that energy.
In industrial buildings a lot of energy is lost through old, single-skinned and/or faulty skylight glazing. Up until the time of the first energy crisis, single-skinned glazing was often used to illuminate industrial buildings; frequently such glazing had a U value of just 8 W/m2K. The amount of energy lost through transmission and leakage depends on how large the glazed area is in relation to the building as a whole: With a 1 m2, single-skinned glazed area, transmitted heat losses alone can easily amount to somewhere between 200 and 300 W/m2.
Risk of accidents
In the past, the supporting structure for the glazing was often made of material that was not protected against corrosion. A build-up of moisture caused corrosion, which meant the substructure for the glazing could frequently no longer meet the static requirements placed on it, resulting in a potential risk of collapse and accidents. Furthermore, solar radiation caused stress cracks to form in the glazing, leading to increased leakage losses or even to the possibility of the glass falling out.
Overheating
Just as energy is lost to the outside through single-skinned glazing during the winter months, in summer the inside of the building suffers from excessive heat due to the solar radiation penetrating the glass. Many companies tried to get around this problem by applying a coating to the glazing; this coating did significantly reduce solar radiation, but it also reduced the incident light allowed to enter the building. Appearance
Coatings, corrosion and breakages to the glass give the glazing a shabby appearance and, if they can be seen from the outside, can have a negative impact on the image of the building and the company it houses. As-is analysis
In order to improve this situation, our specialist consultants analyse the existing structure in terms of removal options, the statics of the substructure, the details of how the roof is connected and whether or not a new installation is possible. Should there be problems with overheating
in the summer months, our specialist consultants can also analyse the ventilation conditions within the building and work on ways to improve ventilation at the same time as they draw up a renovation proposal. Solutions: Option 1: Optimise the existing structure
If the existing structure and glazing are still in a relatively good condition, energy losses can be significantly reduced by installing additional plastic materials. With this option, the existing substructure and glass are retained. An acrylic panel is installed above or below the existing structure by means of special profiles, which creates an additional air layer. The ceiling crossbars and ridge profiles look fantastic and can improve the U value to under 2 W/m2K. During the summer months, dazzling effects and solar radiation are also optimised. Option 2: Remove the glazing/use the substructure
If the glazing has suffered damage or if its appearance has deteriorated dramatically, it is often recommended to replace the affected panes. If the substructure is not rusty and is still able to bear the requisite static loads, a wide variety of plastic materials can be used for renovation purposes. In the industrial field, a 16 mm "K-Structure" pane with an opal tint is often chosen for this task, as it provides a U value of 2 W/m2 and an excellent price/performance ratio. The ceiling crossbars are then usually made from new aluminium materials too, so that the installation not only saves energy, it also looks great. Option 3: Remove all glazing
If the as-is analysis shows that the substructure is no longer capable of bearing the requisite loads, it is recommend to remove the entire structure. Two different systems are usually then available for installation from scratch: if the same appearance is to be retained, saddle rooflights with a slope of 30 or 45 °C; or alternatively, arched arcade rooflights, which generally reduce the volume of air to be heated and demonstrate a good U value. The technical energy properties of the plastic materials are the same for both types of system. A wide range of material thicknesses are available for different span widths, so we can always find a customised solution for every application. Thermal ventilation/smoke and heat extraction systems
During the course of renovation work, i.e. when glass is removed, the existing casements are usually removed too. These casements are difficult to insulate using plastic and also present a significant risk in terms of leakage losses. In order to improve ventilation conditions, thermal ventilation equipment can be integrated into the structures in the form of shutters or cover ventilators in a single-blade or two-blade design. Smoke and heat extraction (SHE) functions can also be integrated into these thermal ventilation systems for very little additional expense. Mechanical ventilationIf the as-is analyses show that mechanical fresh air or extracted air equipment is also required to improve the climate within the building, such systems can be easily integrated into the existing light structure.
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