Ancient forms of architectural glass were far too costly for everyday use and were reserved for the most important buildings in Rome. It wasn’t until the early 1950s that glass windows were widely available. We continue to push the evolution of glass windows today. Engineers are now exploring how energy saving glazing options can help cut costs on heating or air conditioning, as well as provide shade.
Steven Holl Architects, in partnership with Switzerland-based Rüssli Architekten, recently won an international design competition for the new Doctors Without Borders headquarters in Geneva. A major component of the project is tinted photovoltaic glass panels. Comprised of solar cells sandwiched between two layers of glass, photovoltaic glass converts light to electricity. Approximately 40% of the curtain wall of the Doctors Without Borders headquarters will be made up of solar cells, as well as additional panels on the roof. In total, the building is expected to produce about 72% of its own electricity needs. While some transparency is lost by using photovoltaic cells, this reduction helps lower air-conditioning costs in environments where too much heat is absorbed through the windows.
Using Smart Glass to Save Money
Other so-called “smart glass” has the ability to adjust its properties in response to the surrounding environment to block out heat or light. Some of the most basic smart glass applications are a self-tinting rearview car mirror or eyeglasses that adjust to sunlight. It’s proving beneficial in construction as well. It can lower costs for heating or cooling and block ultraviolet rays that may fade fabrics. Electrochromic glazing, which is powered by an electric current, is the most widely-used smart glass. It can be manually turned on and off, as well as programmed to respond to weather conditions.
Taking this concept a little farther, German engineers unveiled Large-Area Fluidic Windows (LaWin) — which are tiny iron particles suspended in liquid within vertical channels of the glass. When employed, the iron particles partially block sunlight and absorb energy from the sun. When turned off, a magnet pulls the iron particles out of the liquid. Similar to photovoltaic glass, absorbed energy is repurposed to provide electricity to the building.
To learn more about window technology, particularly during the winter months, read a world without windows.
Photo courtesy of Issolsa [CC BY-SA 3.0], via Wikimedia Commons