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Let There Be Light

And then God said, "Let there be light," at which point man replied, "How do we get light into these buildings without creating leaks, thermal shorts and, above all, meet these confounding new building codes?" Forgive the revisionist history, natural lighting does save energy and can be achieved efficiently and economically by incorporating "non-traditional" wall and roof lighting systems into insulated metal wall and roof (IMP) panel assemblies.

Daylighting and Energy Savings

Sustainable design is transforming the way buildings are constructed and operated to alleviate negative environmental impact. Natural lighting systems, in conjunction with insulated metal panels, allow design professionals to incorporate the latest green technologies in building design. This can improve energy efficiency and result in substantial savings on electric bills.

Daylighting reduces the amount of internal heat gains caused by traditional electric lighting, as well as the amount of HVAC use required to cool the added heat. Natural daylight also provides occupant satisfaction and thermal comfort in which recent studies have indicated increases productivity and health in workplaces. These innovative green strategies can help new or existing commercial buildings achieve LEED credits in several categories, including Energy and Atmosphere, Indoor Environmental Quality and Innovation in Design.

Furthermore, energy codes such as ASHRAE 90.1, the California Energy Code Title 24 and the International Energy Conservation Code (IECC) have begun to adopt standards to encourage the use of daylighting practices in sustainable buildings. Integrating tubular lighting systems and thermally efficient polycarbonate panels is an important aspect in the design of net zero energy buildings.

Roofs and Skylights

Traditional approaches to skylights in metal roofs are either nested matching corrugated reinforced plastic sheets, or domed polycarbonate assemblies requiring curbs and steel reinforcement. Corrugated skylights are inexpensive, but have always been problematic due to safety issues, little to no thermal resistance and limited product lifespan. Curbed skylights are not only costly, but are notorious for leaking. Only double-domed skylights of this variety provide some thermal resistance. Because IMP roof panels are structurally superior to single-skin metal roof panels, they are able to support Vista, Calif.- based Solatube International's SolaMaster Series (or equal) tubular daylighting devices without curbs or additional steel reinforcement.

Tubular skylight systems are cylindrical employing a "collar" style gasketing that installs and seals easily and effectively. They can be pattern located where needed to meet the specific lighting (lumen) requirements, then installed either on the ground or once the IMP roof panels are in place by cutting a rough opening to the specified diameter. Available assemblies are designed for open roofs or suspended ceilings, and light can be directed and intensified through cleverly designed mechanical extensions. Tubular skylights provide superior illuminating intensity, thermal performance and light consistency compared with traditional skylight assemblies described above.

Wall Lites

For wall lites, again IMPs are a perfect complement for using translucent polycarbonate honeycomb products like Lexan Thermoclick provided by De Pere, Wis.-based AmeriLux International (or equal). The honeycomb design provides excellent thermal performance, structural strength and durability. Individual modules are typically 120 inches high by 19.7 inches wide, and sit in gasketed, lightweight, snap-together, extruded aluminum frames. They can be installed individually or as a continuous strip, and can be cut to fit on-site with a band saw, if necessary.

Set high on both eave walls, they allow for excellent natural lighting in narrower width buildings. Used in combination with tubular skylights in larger buildings, energy efficiency and natural lighting is achieved without leaking or thermal shorts and at a reasonable cost. Polycarbonate honeycomb wall lites are not meant to replace windows and are not designed for mechanical opening and closing.

William Lowery is president of Vacaville, Calif.- based All Weather Insulated Panels for North America. To learn more, visit