Daylight Usage and Benefits

One of the most successful healthcare architecture techniques in recent years has been the increased use of daylighting and outdoor views in patient settings. More glass area, however, means that better glazing is required. For improved energy efficiency of the building envelope, architects are specifying new low-emissivity (low-E) and spectrally selective glass with a range of visible light transmission, between 40 percent and 70 percent, while also offering lower reflectivity than was possible in the past.

While energy efficiency is a growing concern, the issue of reflectivity has emerged as a patient issue. "The low interior reflectance lets patients see outside better, which is shown to improve mood and recovery," says Chris Dolan, director of commercial glass marketing with Guardian Industries Corp. "When it's dark out, reflected interior lighting makes it difficult to see outside, and instead patients see their own reflections, which defeats the purpose of the windows. Low-reflectance glazings reduce the indoor mirror effect, and that's typically more comfortable for patients," and can reduce stress.

Another issue affecting the use of enclosure and interior glazing has been fire safety. Novel fire-resistant and fire-protective glass products allow the use of glass in situations that otherwise limit its use. Fire-protective performance is defined by Fire-Protection Rating-"the period of time that an opening protective assembly" can confine a fire, according to the Glass Association of North America (GANA). Fire-resistance describes how materials and assemblies prevent or retard "the passage of excessive heat, hot gases or flames," says GANA.

"How the glass performs, which is how the 2012 International Building Code defines them, is even more important," says Diana San Diego, director of marketing for SAFTIFIRST. Fire-protective glass blocks the passage of flames and smoke, based on testing to NFPA 252 and 257; it is typically used for 20- to 45-minute door and window applications, limited to 25 percent of the wall area. Fire-resistive glass blocks flames, smoke and dangerous radiant heat, based on testing to ASTM E-119; it can be used for wall and door applications rated at 60 minutes and greater. Because it blocks radiant heat, there are no size limits for fire-resistive glass applications.

The bottom line: Hospitals are now able to use glass partitions for rated interior walls, on property line or party walls, or in stairwells to improve visual security, while meeting the requirements of the code. "We're seeing more and more opportunities for fire-resistant glass to create a greater sense of openness in design or a more relaxed, less institutional feel," says Jeff Griffiths, director of business development with SAFTIFIRST.

Fire-protective performance for glass is defined as the period of time an opening can confine a fire. Fire-resistant glass prevents movement excessive heat, hot gases or flames. Courtesy of SAFTIFIRST