ENERGY AND ENVIRONMENT
Canada Develops New Qualifying
Criteria for Windows and Doors
Natural Resources Canada (NRCan) has announced that it has developed qualifying criteria and levels for windows and sliding glass doors in Canada. Effective April 1, 2004, only those products that meet the new criteria will be considered Energy-Star® qualified when sold in Canada. Previously, the levels used to determine Energy-Star qualification were those set for the U.S. Northern Zone since no guidelines for Canada existed.
The levels have been developed for products installed in buildings of three or fewer stories and used for residential or light commercial purposes. Thermal performance data must be certified by an organization accredited by the Standards Council of Canada (SCC) or by the National Fenestration Rating Council (NFRC).
Products may be qualified using either U-value or Energy Rating (ER). Values given in the tables below are for total product performance only, not center-of-glass, and products may qualify for more than one zone.
Info on the new guidelines visit www.energystar.gc.ca.
Study Uncovers Interesting Findings Regarding Window Leakage
A recent study concerning the water penetration resistance of windows, performed by RDH Building Engineering Ltd., offers some interesting finding regarding window leakage. The Study of Manufacturing, Building Design, Installation and Maintenance Factors found that the occurrence of a water leakage path can be related to the following causal factors:
• Gaskets and tapes penetrations,
• Window design and selection; and
• Quality assurance/quality
Leakage paths were studied and six were charted (see chart on page 30). The L5 path is the one that occurs most frequently for all window types, with no clear trend regarding those that occur the least frequently, according to the report.
Risk of consequential damage also was studied. According to the study, water that moves through the window assembly and is visible on the interior may cause damage to the interior finishes but is less likely to cause damage to hidden wall materials. Water that is held within the window assembly may lead to damage of materials within the window assembly but is not as likely to cause damage to interior finishes or the hidden materials within the wall.
RDH had representatives of the involved industries view the testing results and those from the manufacturing sector said they generally agreed with the assessment results but said that “the building designers dictated many of the choices that were made.”
Representatives from the installation side said “they are installing a product manufactured by another party in accordance with instructions (drawings and specifications) from another party,” thus they have limited capacity of initiating change, according to the study.
The study concluded that the building and interface design and field review sector has the biggest potential impact on the dominant leakage paths and associated causal factors. Additionally, the study concluded that maintenance and renewal plans are not being provided by those in the best position to create an effective plan (manufacturing and building and interface design and field review).
The report states, “Those responsible for undertaking maintenance and renewal activities are not aware of the strategy and details for water penetration control and therefore are not aware of the sensitivity of performance to some maintenance and renewal activity. An example of this would be the need for cap beading of face sealed windows when used in exposed conditions.”
Following are just some of RDH’s recommendations:
• Performance expectations for water penetration resistance should be based on a rational exposure classification system;
• A “Best Practice Guide” for windows should be developed;
• Maintenance and renewal plans should be developed on a building specific basis by those with appropriate knowledge to prepare the plan. This is believed to be the manufacturing sector in combination with building and interface design and field review.
• The manufacturing sector has a general need to increase its focus on quality control;
• All manufacturing facilities should include an in-plant water penetration testing facility;
• Manufacturers have to focus on the design of the entire installed window;
• Manufacturers need to take a more active role in the installation of their product; The manufacturing sector must provide realistic maintenance and renewal recommendations for their products for the intended service life of the products;
• A water penetration testing protocol needs to be developed and mandated for the installed window that also reflects building specific conditions;
• Windows should be specified and selected based on consideration of micro and macro exposure conditions; and
• Greater trade training should be made available and possibly mandated.
RDH conducted another study, “Water Penetration Resistance of Windows: Study of Codes, Standards, Testing and Certification.”
According to that report, “The key recommendation for building codes is the inclusion of requirements that effectively mandate appropriate principles of water penetration control for the range of potential exposure conditions that exist.
“The key recommendations for manufacturing standards involve the explicit consideration of durability through the classification of windows in accordance
with their water penetration control strategy and the mandating of a certification process for manufacturers.”
The report also found that there are significantly fewer failures in the lab testing than field testing and fewer leakage paths in the lab.
Sashlite Unveils Website
Sashlite LLC has recently launched a unique website at www.sashlite.com. The main feature includes a presentation where the user can hear all about Sashlite as well as see how the system comes together. If needed, users can even pause the demonstration and finish viewing it at a later time. The website uses a technology that allows for an almost instantaneous download of the presentation, unlike traditional technologies, which often have a long wait time, according to Sashlite.
The website also features technical information, plant layouts, partner program details and a frequently asked questions section. Another unique feature is a performance tab that allows visitors to click on various parts of the window to learn more about that specific area.
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