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Optimizing Commercial Daylighting Strategies

Six tips for selecting metal-framed skylights and systems

Mcn Kyp Exe Tech Dec17 1

When buildings’ skylights and daylighting systems have deteriorated due to time, weather and use, they can noticeably age building appearances, perform below expectations and cause unsafe conditions for occupants. Properly selecting and specifying a metal-framed daylighting system for new construction and renovation projects will contribute to the building’s beauty and functionality, and result in long-lasting value.

Benefits of daylighting in commercial buildings include cost-savings on electricity use and reduction of energy consumption. Daylighting also has been proven to increase productivity, decrease absenteeism, and deliver overall benefits for mental and physical health. These advantages of commercial daylighting strategies, and the systems that deliver them, also are recognized by such organizations as the U.S. Green Building Council’s LEED rating system.

When selecting a metal-framed translucent wall, skylight, canopy or window to optimize commercial daylighting strategies, check to make sure the system is engineered to address the following:

1. The Framing Members
Aluminum is widely used to produce daylighting systems’ framing members because it possesses durability, yet is cost effective. Different alloys of aluminum can deliver different levels of rigidity and malleability—a more malleable alloy is needed for curved framing systems. An alloy of 6063 typically is used in the daylighting systems industry. Some manufacturers recommend upgrading to a structural alloy of 6105; it is a little more expensive than 6063, but is stronger.

However, aluminum is very conductive; it can easily transfer hot and cold temperatures throughout the framing and into your application. To prevent temperature transfer into your structure, it’s important to use framing that is thermally broken. A thermal break is a literal break in the framing that stops the path of conductivity. Thermally broken framing also includes polyurethane that has been poured into part of the extrusion, filling the gap and further blocking temperature transfer.

2. The Gaskets
Ensure your daylighting system uses gaskets with a low-friction surface. If gaskets are not glued into well-designed gasket tracks, and if they do not have low-friction surface materials, then they will become disengaged over time as the glazing expands and contracts. When disengaged, the glazing comes loose from the metal framing, causing leakage and panel decay, and compromising the structural integrity.

3. A Panel-Setting Mechanism
Be sure that any wall, skylight or canopy system contains a mechanism for the glazing panel to sit on, such as a setting fin or setting blocks. These can be fabricated from a variety of materials, including metal and plastic. Regardless of the material, they are necessary to keep the glazing panels from falling to the bottom of the sill profile, thus making them vulnerable to water penetration, interior condensation and decay. Sometimes, manufacturers forego this component, but it is essential for robust system performance.

4. Refined Components
Daylighting systems with precise engineering that steer clear of excessive hardware are preferable to overly complex metal framing systems. Minimalist framing design cuts down on the time and cost of installation. It also limits the chances for human error and system failures, such as a compromised weather seal and faulty water seepage.

5. Pre-fabricated Systems
Choosing pre-fabricated metal systems helps ensure quality control and avoid installation delays. Only a few daylighting manufacturers offer prefabrication. Most will rely on the installers in the field to fully understand how the systems are engineered, and then field drill the weep holes, miter corners, insert gaskets, etc., in an uncontrolled environment. Precision is difficult to achieve when fabricating under strong winds, sun glare and other environmental factors. Such conditions also can be a potential liability for installing contractors.

6. Experienced Installers
When specifying skylight systems, it is paramount that the trades, roofers and daylighting suppliers, coordinate. For a robust, efficient and cost-effective skylight install, the curbs and flashings on which the skylights are mounted must be fully built and prepared. Remember that not all glazing contractors have experience installing skylights. Proper water management with a skylight system can be even more complex than vertical daylighting systems, and as critical to a building’s long-term performance.

Involving the daylight system manufacturer early in the project is the one of best ways to guarantee that a project will be successful. Qualified manufacturers can assist with daylighting studies, offer guidance on the impact of energy usage, solar heat gain and glare, and support product selection to yield the project’s goals.

A properly installed, well-engineered, fully fabricated, metal-framed daylighting system will offer the best results for achieving an attractive, functional commercial building with lasting value to both owners and tenants.

Jim Leslie is general manager of Exterior Technologies Inc., Pittsburgh. To learn more, go to www. extechinc.com or call (855) 657-3379.