Hurricane Tested Glass - A Hazard for Residents?

Not too long ago a residence in a beautiful neighborhood on Kiawah Island, South Carolina caught on fire. The origin of the fire was an electrical malfunction. Despite the fire department's best efforts the house burnt to the ground and damaged several homes nearby. No one was in the house at the time, so the fire only caused material damage. Reports blamed  - guess what? - the hurricane rated windows and doors of the house. According to the fire department, these units with multiple locking systems and large missile impact rated glass did not give way to the firemen's axes.  

While one has to ask why the firemen did not breach the six inch stud walls or the roof, the question of what to do with hurricane windows in an emergency is an important one. Insurance and local building codes require the use of impact rated windows. Henselstone's tilt and turn windows only have one handle to open to the inside allowing 100% emergency egress. Other manufacturers have several locks that have to be undone to operate the window. Building codes also require operable windows or exterior doors in every bedroom. However, if the house is empty or, a nightmare scenario, children, handicapped, or elderly residents cannot operate the windows, it is almost impossible for someone from the outside to enter the building through hurricane windows. Window manufacturers in cooperation with local authorities have to address this issue. In response to the fire, Henselstone is offering fire departments across the eastern United States to train firemen in breaching windows and doors equipped with impact glass and multiple locking mechanisms. The key to breaking through these heavily laminated units strong enough to withstand small arms fire is ... (let's not tell the bad people, will we!) Come to one of our presentations. 

Energy Ratings and Reality?

Virtually every window in this country is rated for its energy properties. We have seen these ratings, U Value (Heat Transfer Coefficient), R Value (Heat Resistance Coefficient), and SHGC (Solar Heat Gain Coefficient). Any home builder, owner or architect can look up the definition of these ratings and which specifications will satisfy building codes or construction requirements. However, the big question remains, WHAT DO THESE RATINGS MEAN? Claims are abound that a certain window will "save up to 50% energy." Really? 

What consumers have to understand is that these ratings are derived from lab testing of a standard size product. Depending on the ratings (residential, various commercial up to architectural grade), a window of a certain size is selected and tested. As a result, the actual window you have installed in your house most likely does not have the properties described on your sticker. This is why you get these advertisements, "save up to..."  

At a recent visit to an architect we discussed energy ratings. In this case, the windows we discussed had triple insulated glazing rated at a U Value of 0.14. This is quite an energy efficient window (compared to your builder grade product). The value was derived from a window 36" wide and 60" tall (the test specimen). So, the architect asked, what is more energy efficient, larger windows or smaller windows? In this case, the glass has a U Value of 0.09 (R 11), while the frame and sash materials only had a U-value of 0.25 (R 4). In the particular test window, those values averaged to 0.14. Imagine a huge picture window, 8' by 8'. Suddenly the frame (no sash) becomes a minute part of the surface of the unit. Rather than the sticker U Value of 0.14, this window has an actual U Value of 0.11 or, if the frame disappears in the finished wall, the U Value becomes 0.09. Take a tilt and turn window that is only 30" by 30". The glass area is only 24" by 24". Now the frame and sash material makes the whole unit far less energy efficient than the rated value. 

Why is this important? The German government mandates that customers receive not some theoretical energy efficiency, light transmission or structural vale but the real number. Would that not be nice? Only then can you specify the HVAC equipment and wall insulation. Yes, you are right, we (actually they since we know our real values) are only guessing in this country. How much are we wasting on over or under sized HVAC equipment? Your guess is as good as mine!

80% of all Window Warranties are Faulty Installation

You might be able to afford the most sophisticated, perhaps also the most expensive windows and doors. They will have all the tests, little or no air infiltration at hurricane strength windows and water resistance that comforts your heart. Your house will be safe from weather - you think... But will it?  

A customer of ours several years ago specified our product in a hurricane area for a house with masonry walls. Perfect for our impact rated tilt and turn windows and French doors. Also perfect for our engineering services, since the architectural plans as well as the actual construction needed quite some problem solving capabilities. Inexplicably, the builder took our engineering solutions to a competitor, defaulted on our signed contract and got the "cheaper" competitor windows. Now, after less than five years, the house is severely damaged because of water penetration through window and door openings. Not only were the cheaper windows substandard, but the installation was flawed. The water is entering the walls through sill plates, headers, and behind the stucco. 

This is just one of thousands of examples where a window and door package fails miserably. This is why Henselstone insists on working with the architects and builders to design a solid water proofing system, consisting on primary and secondary seal, state-of-the-art water proofing materials (such as butyl flashing tapes and memory foam insulation). We might ask the customer to re-design some details to make sure that the water stays where it belongs - on the outside and is properly drained away from the walls. We also supervise the installation or install with our own teams. Our warranty covers the openings not just the windows and doors. That is why our customers can rest easy! They got what they paid for.

Green Windows and UPVC?

The debate has been raging not only in this industry but also in textiles, food packaging, toys and others: Can UPVC (Unplasticized Poly Vinyl Chloride or rigid PVC) be considered a "green" product?

Like in so many debates the answer is "yes and no." It depends what you are comparing to and how "green" is defined. Lets start with an important upfront definition: In this debate "green" will be used to describe the lesser amount of environmental impact over the lifetime of the product. Using this definition let's look at three distinct areas: The raw materials used to make windows, the production process, and the characteristics/maintenance over life of windows.

1) Raw materials: In the window industry today you have basically four types of frames/sashes (let's exclude glass since it will be same for all four): UPVC, Wood, Aluminum, and Wood covered with Aluminum. There are other metal claddings and profile metals such as bronze and steel but both are disqualified because of their energy properties from this discussion. In Europe steel windows are not even allowed to be used in residential construction. UPVC is manufactured from crude oil and rock salt through a serious of stages. The big difference between PVC and UPVC is that the latter does not contain phthalates, the softening acids that easily leak into the environment as the plastic polymer disintegrates over time. As a result UPVC does not gas out toxic substances. While crude oil is a non-renewable fossil fuel, the main ingredient rock salt is available in virtually unlimited amounts.

 raw materials used in PVC

raw materials used in PVC

Wood as the substrate for window frames and sashes is still the most frequently used. Depending on the type of wood (pine, fur, meranti, mahogany) used, the raw material could be from sustainable sources or not. Assuming that most large manufacturers have now fully converted to sustainable sources, the wood has to be transported from the harvest location to the factories, usually a large distance especially in the case of tropical wood species. 

Aluminum is the least "green" raw material because bauxite is a non-renewable mineral which requires large amounts of energy to be converted to the end product.

2) The production process: UPVC windows are manufactured from standard profiles. In the manufacturing process these profiles are cut and welded under strict environmental guidelines. For coloring, either colored profiles are used (the color is in the polymer) or, more frequently, a thin PVC layer of color laminate is melted and pressed onto the profiles. Wood window profiles are made by laminating several layers of wood together in a way that reduces warping. The lamination process involves water soluble glue. The these profiles are then run through routers, saws, and joiners. After the joints are glued, the window frames and sashes go through a painting and sanding process. While all these manufacturing processes have been optimized to meet environmental standards, wood requires far more extensive processing and application of glues and paints than UPVC. Aluminum windows are processed very similarly to UPVC, with profiles being cut and joined either through welds or glue. All aluminum windows are powder coated for color. In the comparison UPVC windows are produced with the least environmental impact.

3) The characteristics and maintenance over life: UPVC windows are virtually maintenance free. Colors stay on the profiles for a life expectancy from between twenty and fifty years. Wood windows require periodic re-finishing depending on exposure. Typically, wood windows are painted every three to five years. The life expectancy of a wood window is between seven and fifteen years. Aluminum windows are powder coated and, while the colors fade over time depending on exposure, these windows do not require maintenance. However, one of the biggest disadvantages of aluminum versus UPVC is that in a salt air environment aluminum oxidizes, reducing the life expectancy to ten years. In comparison, UPVC windows require less maintenance and have a higher life expectancy than the other types of windows. The real disadvantage of UPVC is the issue of end-of-life disposal. While European manufacturers are forced by their governments to provide collection and recycling services, here in the United States there is little control over the disposal of vinyl products. While UPVC is fully recyclable and the percentage of recycling is increasing year by year, the lacking regulation of the industry does put a damper on an otherwise "green" product with the least environmental impact from raw material, manufacturing to life expectancy and maintenance.