Performance Benefits of Casement Windows
Casement windows have grown in popularity over the last 20 years with Midwest home builders, and for good reason. A casement window offers many performance benefits over hung and slider windows. The benefits described below, will help you build a better building envelope that will increase the window energy efficiency, comfort and durability of the homes you build.
Improved Window Energy Efficiency: A casement window will typically have a full frame U value that is 0.03 to 0.05 better than a hung or slider window. This is achieved by increasing the glass to frame ratio. A higher ratio of glass to frame improves the window energy efficiency because it creates less conduction of heat through the glass spacer bar. Hung and slider windows have a 50% lower glass to frame ratio because they have two sashes instead of one.
Decreased Air and Water Infiltration: Our fiberglass casement windows have AAMA tested air infiltration rates as low as 0.01 cfm and a Design Pressure of 70, whereas a “good” slider window is typically rated around 0.20 cfm and DP-30. Based upon independent AAMA testing, our casement windows are twice as effective at preventing air and water infiltration.
Improved Comfort: With their superior U values and lower air infiltration rates, your customers will be able to feel the improved comfort levels in their living spaces.
Increased Visual Light Transmittance: Help home owners decrease their lighting costs while improving the view outside. Since casement windows have slimmer frames and do not have a meeting rail in the middle, casement windows allow up to 20% more visual natural light than hung and slider windows.
Improved Security: Casement windows are the most secure operable type of window you can build with. With modern multipoint locking systems, casement windows create a secure and balanced seal that cannot be pried open. With a hung or slider window, an intruder can simply stick a crow bar under the sash and pry it open.
Competitor Comparison: Not all casement windows are equal. The chart to the left compares the AAMA Design Pressure rating of our fiberglass casement window versus Marvin’s and Pella’s fiberglass casement. Our higher DP rating is achieved through thicker pultrusion walls and triple Qlon weatherstripping.
|Marvin Ultrex||DP 40|
Solar Tuning Your Home
EnerLux offers the unique service of consulting with our customers to help them achieve maximum energy efficiency for their home. As the window industry continues to move towards standard low solar heat gain products, the building industry is missing an easy opportunity to save significant amounts of energy through solar tuned windows. Each region of the USA has different solar tuning requirements.
Homes built in the south will need more low solar heat gain products and homes built further north require higher solar heat gain products. We will start with north facing windows and work our way around. We will assume that the home is located in Nebraska, a state that has more heating degree days than cooling degree days.
North: The north receives essentially zero direct sunlight. Our recommendation is to install a window that achieves the best U-factor. The SHGC is not an important factor for north facing windows.
East: Windows on the eastern exposure of the home receive early morning sunlight. For a home located in Nebraska a high SHGC glass like EL Glass 378 can be beneficial because the early morning sun will help heat up your home. An additional benefit of high SHGC glass is that it offers better visual light transmittance so you will not have to turn on your lights as frequently.
South: When a home has properly designed roof overhangs, a high SHGC glass is extremely beneficial in the upper midwest. Assuming your home has a roof overhang that extend approximately three feet outwards, you can achieve a successful passive solar design. The idea behind southern exposure passive solar design is that in the summer the sun is high up in the sky and the roof overhang will shade the home, preventing the windows from absorbing the suns heat. In the winter, when the sun is low, the sun will not be shaded by the overhang because the sun will shine directly into the windows. The high SHGC glass allows for maximum heat absorption during the winter months. There are other important factors to be considered, such as landscaping and thermal mass. Here is a link to the WikiPedia website that has additional information on passive solar design. For regions that have more cooling degree days than heating degree days, a low SHGC glass is needed, like EL Glass 426.
West: The sun sets in the west. Regardless of the season, western facing windows will always receive direct sunlight and should use a low SHGC glass like EL Glass 426. It is a good idea to plant decidous trees in front of western facing windows because during the summer months the leaves on the trees will provide shading and during the winter months when the leaves have fallen off, more of the suns heat will be let in to to help heat the building. Regardless of the glass you use, it is a good idea to keep the number of western facing windows to a minimum.
Benefits of selecting Fiberglass for windows and doors
Stronger: It is 8x stronger than vinyl and 2x stronger than aluminum.
More Energy Efficient: 500x lower thermal conductivity than aluminum, so it doesn’t allow heat or cold from the outside into your home.
Longer Lasting: Almost zero thermal expansion rate (essentially the same rate as glass) means tighter seals against weather and longer lasting.
Lower Maintenance: Virtually maintenance-free frames stay true to form due to strength of materials. No need for sanding, painting, or staining.
Environmentally friendly: Our material uses less embodied energy and resources to manufacture. Made from partially recycled materials.
More Durable: Won’t discolor, warp, rot, corrode, dent, or rust. Can withstand winds up to 203 mph, and does not absorb moisture.
Slimmer in profile: Because of the strength of the fiberglass, the frames are slimmer allowing more visible glass area in each window.
Unlimited in Design Possibilities: Offered in virtually unlimited colors and an interior wood veneer.
Installing a new construction window
For proper installation of your windows and doors, we highly recommend using DuPont flashing tape. Here is a great slideshow presentation (link) by JLC magazine on how to properly flash a new construction window.