Glass as a full component in energy-efficient building envelopes

It is the technical trend of recent years: glass is playing an increasing role in modern facade construction. The proportion of transparent facade parts is structurally increasing, and that is obviously no coincidence. Thanks to technological developments in glazing and aluminum profiles, glass can nowadays insulate just as well as a closed facade. Moreover, it provides more daylight, spaciousness and aesthetics.

“High-quality glazing prevents heat loss and makes energy-efficient heating possible, but only if smart building concepts, suitable profile material and correct installation are also chosen,” says Dennis Schneider, managing director of SUNFLEX Aluminiumsysteme GmbH.

The current generation of windows and sliding doors shows what is technically possible. For example, SUNFLEX offers the SF80 sliding window system with a Uw value from 0.8 W/m²K, depending on size and glass construction. Even with a glass area of up to 98 percent, thermal insulation is maintained. The SF75 aluminum folding wall also achieves excellent values with a Uw value of 0.9 W/m²K. “Thus, clients benefit from energy savings as well as a slim profile design,” Schneider said.

Energy Balance

With low heat gain and high solar gain, the overall energy balance of a building improves significantly. By orienting windows towards the sun and insulating them well at night, heat gain through the glass can actually exceed heat loss. The result? A positive energy balance. ’With triple glazing, windows gain more solar energy during the heating season than they lose in heat,“ says Schneider. ”Against overheating in summer, we recommend shading or special coatings that allow less solar radiation through.“

The window construction itself also determines performance. Up to 35 percent of a window's heat loss occurs through the frames. That's why SUNFLEX's aluminum systems feature high-quality thermal breaks and come with guidelines for airtight installation. “This not only reduces energy consumption, but also improves sound insulation and prevents mold,” Schneider concludes.

With these systems, SUNFLEX is responding to the growing demand for energy-efficient building envelopes without making a single concession to design and transparency.