In our last issue, we discussed a number key factors to be taken into account when choosing facade glass. This issue will focus primarily on the environment and demonstrate that designers of glass buildings are also thinking about our planet.
We will be looking at three environmentally friendly construction methods:
- Insulating buildings: cutting C02 emissions by reducing energy loss via glass.
- Generating energy: cutting energy consumption by using glass as a construction component as well as to generate electricity.
- Using sustainable materials and environmentally friendly manufacturing techniques.
Since E-levels are constantly being lowered under current legislation, building materials must perform better and better. With glass covering a large part of a building’s facade, more of an effort must also be made in this area. Modern technology is delivering Ug values of 0.5 W/m2K for triple glazing and 0.9W/m2K for double glazing, the latter thanks to AGC’s new Thermobel 0.9 range. How? By adding a second hard coating (in position 4) to a double-glazing unit already equipped with a soft coating (in position 2). The new range is primarily used where conventional triple glazing is too thick for the profiles being used or already installed.
Insulating glazings intended for glass facade spandrels, such as the Thermobel VIP (Vacuum Insulation Panel) glazing developed by AGC, can already achieve a Ug value of 0.15 W/m²K. Thermobel® VIP is designed according to the double glazing principle. The internal finish can be an enamelled glazing or a combination of a (toughened or standard) glazing and an enamelled metal covering (steel or aluminium).
In the double-glazing spacer, vacuum components are inserted to ensure optimal thermal and sound insulation. The external glazing can be enamelled using a wide range of colours, so you can create the perfect combination of vision glazing and spandrel glazing based on the Colorbel Color Matching range.
You can also create a contrasting effect with Artlite Digital: a new digital silk-screen printing technique enabling you to customise your glass in any way you want.
In addition to providing necessary thermal insulation, facades can generate energy by transforming solar radiation into electricity. This system, known as building-integrated photovoltaics (BIPV), consists of a laminated safety glazing with embedded photovoltaic cells. It can also be assembled as a double-glazing unit. The key difference between the BIPV system and regular photovoltaic panels is that BIPV forms part of the building and is as such entirely integrated into its framework, whereas photovoltaic panels are considered as independent components. Skylights (see Image 1), transparent glass panes, canopies and glass roofs for atria or conservatories are all ideal applications for the BIPV system.
SunEwat, a product developed by AGC, is a BIPV module integrating all the current functions of glass products. All SunEwat modules are individually examined and a different configuration is required for each one. Therefore, architects can create modules according to their own specification and obtain a final result which is in keeping with their projects. The inclusion of photovoltaic cells on a building’s facade also makes it more environmentally friendly. Total energy generation depends on the orientation and angle of the glass, as well as the number of embedded cells.
Using sustainable materials
Using sustainable building materials is becoming increasingly vital. AGC is the first European glass manufacturer to be awarded the Silver Cradle to Cradle (C2C) label for its float glasses and soft coatings. Cradle to Cradle.
(C2C) is a rigorous programme led by MBDC with a view to assessing the sustainability of products as a whole, i.e. throughout their life cycle. The aim of this approach is to certify the products of the most environmentally friendly companies, from the very first stage of production to the decomposition of residual materials.
The Silver C2C label allows us to earn a number of additional points as part of a whole range of environmental assessments, such as LEED and BREEAM, based on the performance of buildings in the relevant domain.
Thermobel Green (AGC) is an environmentally friendly alternative to standard insulating glass (double or triple glazing). The manufacturing process has been adapted to enable the more rational use of sealing compound during assembly. When installing glazings into frames, Thermobel Green truly spells an end to surplus sealant for a more aesthetically pleasing result. Thermobel Green can be ordered as part of a standard delivery with arrissed edges to avoid any risk of injury during glass handling. This finish also helps to minimise the risk of breakage during handling, storage and transport.
Ir. Thomas Hens (Technical Advisor, AGC Glass Europe)
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