High Performance Glazing
The glass (high performance glazing) which goes inside your structure, doors or windows is a very important decision. There are literally thousands of different glass types on the market today. The choices can become overwhelming when the consumer does not understand glazing terminology and process. Solar Innovations® is here to help assist in this process. The following paragraphs discuss the basics on understanding glass types and lays out a format for picking the right glass. There are three major types of glass, some of which you may have heard.
The most primitive type of glass is annealed glass. This glass is found in kitchen cabinets and glass vases. When this glass breaks it shatters into sharp jagged pieces and falls onto the floor. Solar Innovations® does not use annealed glass.
The next type of glass is tempered glass. Many people have heard of this type. This glass is incredibly strong and is not prone to breaking. However, when it does break it shatters into small squares and collapses. Solar Innovations® uses tempered glass in its doors, windows and the walls of its glass structures.
The third type of glass is laminated glass. This glass consists of two pieces of glass, formed together with a polyvinyl butryal (PVB) inter layer. The PVB is invisible to the eye but acts as glue to hold the pieces together. Upon impact, the glass breaks into pieces that look like a spider web but it does not fall out of the frame. Many times windshields of cars are made out of this glass. Solar Innovations® uses this type of glass in the roofs of its glass structures. If the glass in the roof breaks, it will splinter but will not fall on a person’s head. The majority of building codes across the country require laminated glass in roofing. Another benefit to laminated glass is that 99% of all harmful UV rays are removed when laminated glass is utilized.
After the glass type is chosen, the pane must be picked. There is double pane (insulated) and single pane (monolithic) glass available. Insulated glass consists of two pieces of glass in a unit with an air space between the two pieces. This glass unit is commonly found in all new windows. The air space and second piece of glass helps to insulate the room. Cold air or hot sunlight has to pass through the air and the second piece of glass. The insulated unit greatly helps to manage the interior temperatures.
Monolithic glass consists of only piece of glass. This is not recommended for any applications where there will be wind or water touching the glass. If there is a blizzard outside, the snow will touch the glass, make it cold and the bitter temperature will pass into the home. An interior application such as a folding wall partition to divide a dining room and living room is very well suited for monolithic glass.
Now that the unit is picked, a tint must be selected. This is where the application of the glass is needed. There are generally two categories to pick between: color tint and LoE. Color tints are just as they sound. A color is added to the glass for aesthetics or for a specific purpose. Blues and greens are often used along coastal areas to enhance the look of a commercial or residential building. Grays and bronze tints are used for privacy and sometimes can be used for controlling light. Other colors such as purple and red are available when required.
When light entering a room is an issue, low emissions (low-e) glass should be used. There is a slight coating adhered to the glass which is the LoE. It is barely visible to the naked eye. Only when held next to a piece of uncoated glass can a difference in appearance be noticed.
The glass reduces the amount of sunlight which enters a room. This helps to cut down on extreme heat build-up which make sunrooms and conservatories unpleasant. Another large benefit to low-e glass is the reduction of UV-rays which penetrate a room. This means that fading to objects within the room such as furniture and draperies will retain their color for longer. The fading is slower than an uncoated piece of glass.
The application of the glass is key here. Growing plants under low-e glass requires a specific type whereas if people are the main occupants then the strongest low-e can be utilized. The following link discusses applications for different kinds of glass. There are several different levels of low-e which are illustrated in the lower chart. .
Common LoE Glass Types
|Type||Clear Insulated||LoE 272||LoE 366||LoE 240||LoE i81|
(with 366 & Argon)
|Suitable for Plants||Yes||Yes||No||Roof = Yes||No|
|Suitable for People||Yes||Yes||Yes||Yes||Yes|
|Solar Heat Gain Coefficient||0.76||0.41||0.27||0.25||0.25|
|Special Benefits||None||Cuts down on UV rays which burn plants but still lets in enough light for plants growth.||Lets more light in than other options, but keeps more heat out. Excellent fading protection.||Ideal for reducing glares. can be used in roof for plants with 272 in the walls.||Triple pane performance requiring only double pane glass.|
366 offers Solar control with year round comfort. This type of glass blocks solar gain and assists in energy savings. During the hot months of summer heat is kept out of a room while in the winter, the heat is retained in the space. These factors will assist in reducing your heating and cooling costs. 366 also has a high visibility. When looked through the naked eye will not notice a difference. The glass is not cloudy or tinted bronze. The glass will block 95% of UV rays which increases fading control to your furnishings, draperies and flooring.
272 is the clearest option in LoE glasses. The color difference is only noticeable when placed next to a clear piece of glass. This ensures a natural view out of your windows. The glass reflects heat in summer and captures heat in winter which offers energy savings. 272 blocks 84%of UV rays, aiding in the preservation of your interior furnishings and finishes.
240 is the best LoE option for glare control. This glass type absorbs 60% of sunlight, which reduces the amount of light entering a space to 40%. The glass has a slight tint due to its glare control, which looks like a slight blue when closely inspected. 84% of UV rays are blocked.
I81 triple pane performance when paired with a low-e coating on second pane of glass. I81 reflects heat back into a room during the winter months and reflects it during the summer. This glass type has the best available u-value. By using i81 you are saving money because you are purchasing the coating on the glass and not another piece of glass, argon and spacer. You are able to achieve the performance of triple pane glass, with only a dual pane unit, for a fraction of the cost. I81 is also suitable for plant growth.
For more information on Solar Innovations, Inc.’s Glazing Pages, please visit the links below: