Leed Benefit from using Energy Efficient Glass Block

Midwest Homes And Businesses Benefit From Energy Efficient Glass Block Windows

When homeowners and business owners need versatile and environmentally friendly window solutions, they turn to energy efficient glass block.

Energy Efficient Glass Block can help with Leed Points for Architects

It seems that energy efficiency and “green building materials” are on the minds of many homeowners, contractors, business owners and architects these days.  The reasons are many, but the primary reason that most people are going green is that in the end, they save money through reduced energy consumption costs.

Windows are a huge source of energy loss in today’s homes and businesses. Basically, windows are giant holes in your walls. This allows both solar energy and cold temperatures to be transferred into your home or business. While we all need the ability to allow natural light in, we don’t need to be throwing money out those windows on increased heating and cooling costs. One such way to reduce heating and cooling costs in both residential and commercial building applications is by installing energy efficient windows.

Many times, when security or privacy is a concern, traditional windows do not provide the protection that may be required. For these applications, glass block windows are typically installed. Glass block windows are known for their ability to stand up to would be intruders and to keep prying eyes out, but did you also know that they can be energy efficient? If energy efficiency is important to your new construction or remodeling project, you may want to consider installing energy efficient glass block windows.

The benefits of installing energy efficient windows aren’t just limited to a reduction of heating and cooling costs. For builders and architects that have been charged with decreasing their client’s carbon footprint, energy efficient windows are a must. This is especially true for construction projects that are vying for LEED Certification. Using energy efficient glass block is a great way to earn LEED points. Not only are these windows energy efficient, but they are also constructed of green materials. Also, glass blocks that are manufactured by the Pittsburgh Corning Company are manufactured within close proximity to many Midwest cities, which further contributes to LEED points.

When choosing to install energy efficient windows, it is important to understand the four ways that a window can transfer heat in and out of a building. Once you have a grasp on the basics, you can begin to understand how the energy efficiency of glass block windows is measured.

·      Convection: This is the loss of heat between the air in a building and the air outside through the glass of the window.

·      Radiation:Solar radiation enters the building in the form of heat. Infrared radiation transmits warm interior temperatures to the outside.

·      Conduction: Is the transfer of heat energy through the solid materials in a window’s frame.

·      Air Leaks: When air passes between a wall and the window frame, heat is transferred both in and out of a building.

Energy efficiency in traditional windows can be measured in a couple of ways. They include measuring a window’s U-Factor and Solar Heat Gain Coefficient. The same is true for glass block windows.

·      U-factor:This is a measurement of the rate that a window transmits non-solar heat or the thermal conductivity of a window.

·      Solar Heat Gain Coefficient (SHGC):This is the measurement of the radiation from the sun that is transmitted into your home through a window.

Traditional window manufacturers use a variety of techniques to increase a window’s energy efficiency.  The use of multiple panes of glass, gas fills between panes, and Low-Emissivity (Low-E) coatings are all common ways to reduce the transfer of heat between the interior of a building and the outside. Glass blocks, however, are already very energy efficient. Each glass block is like a mini double paned window. Glass blocks are constructed by taking two pieces of glass and fusing them together with extreme heat. This process creates a vacuum of air on the inside of the block. This provides insulating properties that are better than a traditional single pane window.

Energy efficient glass blocks take this process a step further. Pittsburgh Corning places a glass pane with a Low-E coating in the middle of all energy efficient glass blocks. This provides the following three benefits:

·      Keeps buildings warmer in the winter and cooler in the summer months

·      U-Value is increased over that of regular glass block

·      Solar Heat Gain Coefficient(SHGC) is increased by 60% of that of regular glass block


Energy Efficient Glass Block can be used in an Office Building


Energy efficient glass blocks can be installed in one of two ways. They are either installed in a prefabricated frame, or they consist of an un-framed, prefabricated panel that is mortared to the opening of a window.  Below are the U-factors for Energy Glass Block Panels.

·      Un-Framed glass block panels have a U-factor of 0.34

·      Framed glass block panels have a U-factor of 0.38

For those that are still on the fence on whether energy efficient glass block windows can be as efficient as traditional windows, here are some surprising statistics. According to the United States Department of Energy, energy efficient glass block windows can outperform many types of traditional windows. Listed below are the U-Values of traditional window types with either a wood or a vinyl frame and an insulated spacer:

·      Double paned glass with ½ inch air space – U-Factor = 0.48

·      Double paned glass with ½ inch air space with 0.20 Low-E coating – U-Factor = 0.39

·      Double paned glass with ½ inch air space with 0.10 Low-E coating – U-Factor = 0.37


Pittsburgh Corning energy efficient glass block window panels have been independently tested by the National Fenestration Ratings Council(NFRC) and the American Society for Testing and Materials(ASTM) and received the following results:

·      ASTM C1363 thermal transmittance (unframed U-Value of 0.34).

·      NFRC 201-2004 Solar Heat Gain Coefficient of 0.27 (framed) blocks assembled with a silicone spacer system.

·      ASTM E2190 – 08 Standard Specification for Insulating Glass Unit Performance found the glass block showed no evidence of condensation when tested to -60°F.

Great uses for Energy Efficient Glass Block to get Leed Points

Independent and government testing have all concluded that energy efficient glass block can be as effective and even outperform several types of traditional windows when it comes to energy conservation. While this is impressive, glass block windows provide many other added benefits that you simply can’t get with regular windows. Some of these benefits include:

·      Added Security

·      Privacy

·      Elegance and Beauty
Patterns for Pittsburgh Corning energy efficient glass block windows include Decora™, Delphi™, IceScapes™, and Vue™

·      Reduced sound transmission

·      Resistance to graffiti

If any of the above is important to your building or home, glass block windows are an excellent choice. The use of glass block is ideal for use in commercial businesses as well as residential homes that require a versatile solution that traditional windows can’t provide. When looking for a green building material that can help to reign in heating and cooling costs, look no further than high efficiency glass block windows.  


If you have any questions about the different types of energy efficient glass blocks for sale contact the experts at Quality Glass Block and Window Co. They offer affordable pricing on American made energy efficient glass block products from Pittsburgh Corning. From glass block installation services, glass block sales, tools, and advice their dedicated professionals have everything you will need to complete your glass block project.