Contemporary Canadian Glass

By Brian Burton

The author stands in front of the Toronto’s Direct Energy Centre which boosts a 30-storey wind turbine producing 1 million kilowatt hours of energy per year - the first of its kind in North America and the first permanent turbine in the City of Toronto. It is also home to a permanent educational exhibit which explores energy use and the environment and features interactive displays showcasing sources of energy and methods of energy conservation.

The standard textbook definition of fenestration, which finds its roots in the Latin word for windows fenestra, refers to the design, arrangement and portioning glazing component systems within a building.  However, the topic involves much more than merely glazing design and placement.

In fact, in the field of building science we typically apply the term to any “controlled” aperture in the building envelope that permits the passage of air or light or serves to enable entry and egress of occupants. As such, fenestration components are considered a key element of façade engineering. In addition to a huge list of glazing materials, the elements include internal & external shading systems, skylights, clerestories, roof monitors, light pipes, and tubular daylighting devices. Doors are included in the list because they are operable and allow entry or egress and many have glazing components.

Although it is a highly technical and complex subject, I can assure you it is also an art form.

In Canada, where the citizens are 80% urbanized and typically spend over 90% of their time indoors, obviously these components also play an essential role in our well-being. We spend more money on construction per capita than just about any other country in the world and fenestration components are generally considered the most expensive element of the building envelope.  Global demand for fenestration products will reach the $125 billion mark in 2011.

These components act as a filter of conditions between inside and outside and play a significant role in achieving quality of life and comfort in buildings by bringing in natural light, solar heat, and fresh air.  They also serve as a physical and/or visual connection to the outdoors.

They are subject to all the elements of the outdoor environment including freeze-thaw cycling, UV radiation, driving rain, snow, heat stress, wind loads, impact, dust, acid rain, impact, forced entry and deliberate abuse. These components are also exposed to conditions on the interior including humidity, condensation, temperature variations, and the effects of occupancy.

In addition to controlling heat flow, sound transmission, solar radiation, air and rain leakage, fenestration components are expected to transmit light without causing glare, allow entry of fresh air without causing drafts while preventing entry of insects, to be airtight but easy to operate, and to bring in solar heat in winter while preventing solar heat gain in the summer. As I like to point out – we should probably be thankful that fenestration components are rarely called on to perform all of these functions at the same time!

Also often overlooked is the important function these components play in comfort and safety of the occupants which buildings scientists consider to be one of the most important functions provided by the building enclosure.

We all know that the ability to control fenestration components is very important to the occupant. Technology has granted us the means and we have come to expect more control over nearly everything in our environment that affects us, including the elements involved in fenestration.

I have been involved in a longstanding debate with several academics involved in the field of building science who insist the specialty should be called building “physics.” However, I know quite well that psychology is a major component of fenestration and, as a result, the use of the term physics is not appropriate. In actual fact it is part of environmental psychology, which examines the interrelationship between “built” environments and human behaviour.

Even though we have been manufacturing glass for thousands of years, the full potential of modern fenestration products has not been fully exploited to date. One architect I spoke with did point out, however, that it took us 2,000 years from the time we discovered “blown” glass before we were able to manufacture glass strong enough to safely fabricate windows. However, once we had mastered the art we did not look back. The use of glass in buildings is so popular that it appears close to dominating construction.

The use of glass in buildings is increasing and innovation in fenestration products is altering the way we live our lives. Glass is widely used in almost every aspect of our daily lives:  in our homes, offices, cars, computers and telephones.

Glass technology has its own language. When I visited the web site for the Corning Museum of Glass it listed 817 words that were unique to the glass industry. Glass innovations such as computerized control systems, coating techniques, solar control technology, and the integration of micro-electronic and mechanical know-how to create “smart” glass (able to react and respond to external forces) are constantly evolving. I have also noticed over the years that many innovations and inventions incorporate glass components almost routinely, perhaps because it is “invisible.”

We may take it for granted; however, glass has managed to gradually transform agriculture, horticulture, architecture, transportation, medicine, science, art and even our culture. The earliest form of glass that was discovered by mankind was that of the natural glass called obsidian. Obsidian is a natural bi-product of volcanic eruptions and it was prized by prehistoric societies the world over for its colours, sharp edges and workability. It can be fractured to produce weapons, tools and arrowheads. It can also be polished to create mirrors. Because of its scarcity it was traded around the world for centuries to, among others, the Native Americans, who prized this unique substance. Also on the list of natural glass is fulgurite, created when lightning strikes sandy soils under the right conditions, and tektite, which is created from meteorite impacts – extraterrestrial glass!

The story I hear repeated very often as told by the Roman historian Pliny tells us that Phoenician traders noticed that a clear liquid formed when the nitrate blocks on which they placed their cooking pots melted and mixed with sand from the beach. The tale makes for interesting reading, but I for one am highly sceptical that it is true. I suspect that, as with many other inventions, it is a case of man “mimicking” nature; in this case observing what occurs during volcanic action or lightning in direct contact with silica sand and then experimenting in an attempt to duplicate the phenomenon.

There are nine primary uses of glass.  These include:

• As a medium for art.
• As a substitute for precious stones/jewellery.
• For vessels and vases, which eventually led to the invention of the glass bottle.
• Glass and glazing used in windows, fenestration components, insulation and construction products.
• Glass used for mirrors.
• Lens, telescopes, eyeglasses.
• Scientific and medical instruments which created an interest in optics during medieval times.
• Cameras, television, computers (e-glass), appliances, automobiles, telephones, and many more electronic devices.

There are some ways glass is used which are miscellaneous, esoteric and unusual.  To list only a few, these include items such as glass clothing, glass bullets, fire grenades, glass furniture, liquid crystal windows, suspended particle devices, glass pavements, apotropaic glass, Libyan Desert Glass, witch balls, uranium glass, neodymium glass and, my favourite, glass slippers.

Brian Burton was recently appointed to the Personnel Committee for the CSA’s Fenestration Installation Technician Certification Program. Brian is a Building Science Marketing Consultant for Kleinfeldt Consultants Ltd and can be reached at bburton@kcl.ca or visit www.kcl.ca