Mr Biler, what is important to be aware of nowadays with a window?
Biler: The increasing urbanization around the globe calls building developers and architects to create more living and working spaces. Glazed façades, windows and doors are thereby key elements. They protect from wind and weather and allow for creating light-flooded interiors and building envelopes that sustainably ensure the comfort of the inhabitants. “With regards to energy efficiency, builders are increasingly looking after the glazing. But it’s mostly the frame that makes the difference.
What frame materials does your company use most frequently and what makes them different?
Biler: We develop innovative façade systems for reputable objects all over the world. Aluminum is thereby most commonly employed. Its structural strength allows for light and slim frame designs. Yet, the metal’s high thermal conductivity needs to be compensated. Our metal frames consist of an inner and an outer shell, stably interconnected by an insulating profile such as for example ‘insulbar’ from the German manufacturer Ensinger. Its material and design allows for creating energy preserving metal frames – even for passive houses.
Why have you used Ensinger products?
Biler: Ensinger supports the fenestration industry with comprehensive services in configuring the optimum profile: e.g. with an easy-to-use product selector on its website as well as personal expertize in application engineering. In the development phase, they provide competent advice from the project-specific choice of material and geometry, energetic calculation and design to rapid prototyping. And they continue by ensuring the highest quality in processing, handling and logistics, up to the application of the insulating profiles.
Along with the quality, variability and innovation of the product, these services make the difference for us. Project specifications vary and are often challenging. Since we have set ourselves the ambitious goal of becoming the best façade company in the world by the year 2023, we rely on outstanding partners. This particularly applies to our efforts to further increase the energy efficiency of our solutions, as the building envelope has a lasting effect on the comfort and cost-effectiveness of an object.
What materials do you use for the insulating profile?
Biler: The basic material for insulating profiles is a glass fiber reinforced polyamide 66. Highly insulating, stable and yet elastic, it provides excellent mechanical properties and durably resists every climate and weather. Its coefficient of linear thermal expansion is similar to metal, resulting in minimum material stress during temperature shifts. And, what is also interesting is that all profiles can be equipped with flags, coated with low-E-film (LEF), to reduce loss of heat even more effectively.
How do you reduce energy losses?
Biler: Other than the translucent glazing, which can generate energy gains, the frame is part of the opaque building envelope. To reduce energy losses to a minimum, the frame portion of the window box-out, which can vary from over 20 percent to below 10 percent, should be as small as possible. This can best be achieved by using metal with a highly efficient thermal break. For Metal Yapi’s projects in Turkey for example, the expected overall thermal transmittance value for a window or a curtain wall is often 1.5 W/m2K or below.
Although the building code TS 825 currently requires an UW of only 2.4 W/m2K, investors want to further reduce energy consumption in their buildings. Not only for the eco-image, but also to remain more independent from potentially rising energy costs – in energy importing countries such as Turkey this is an important factor because the buildings are used for decades. One example is the Orjin Maslak, a 16-story office center in Istanbul. Its aluminum-framed double façade achieves an UW of 1.26 W/m2K. It was one of the first buildings in Turkey to be awarded a LEED Gold rating in April 2015.
Looking into the future: how will the Uw values change?
Biler: Metal Yapi is equipping a growing number of prestigious buildings with thermally insulated façade systems, currently reaching UW values down to 1.2 W/m2K in Turkey. While the Mediterranean climate is rather mild, the demand for even lower U-values increases in colder climates. Using ‘insulbar’ by Ensinger, Metal Yapi even achieves passive house standards according to PHPP, e.g. at “The One” (UW of 0.90 W/m2K) and the “Belliard 40” (UW of 0.75 W/m2K) in Brussels, Belgium.
Mr. Biler, thank you very much for the interview.