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Insulated Metal Panels And ASHRAE 90.1-2007

By Scott Kriner, Technical Director, Metal Construction Association

The quest to improve building performance is getting more complex, and that’s clear when considering changes in the ASHRAE 90.1-2007 Energy Standard for Buildings Except Low-Rise Residential Buildings. In an effort to make buildings more energy efficient than those designed to the 2004 standard, ASHRAE 90.1-2007 includes new minimum insulating values, which can be found in Addendum “g” of that document, and seen in the accompanying comparative chart.

To meet the latest standard, architects and owners must first determine which standards apply to a particular building’s site. And that’s not always as simple as it sounds. At present, there’s no set standard that tells architects and owners which code requirements apply within a given municipality or state. And it’s important to remember too that ASHRAE 90.1-2007 is a standard, not a code.

Many states have adopted the IECC (International Energy Conservation Code), which is part of all the ICC (International Code Council) codes. The IECC references ASHRAE 90.1 with regard to commercial building energy requirements. So, if a state has adopted the IECC that references the most recent 90.1 standard, commercial buildings in that state would be required to meet ASHRAE energy standards set by that state.

Timing is also part of the challenge. The ICC supplement cycle is not necessarily in sync with ASHRAE’s code adoption schedule, so the most recent ASHRAE standard may apply in some areas but not others. To complicate matters, some municipalities do not recognize the ASHRAE addenda. In addition, the USGBC’s LEED program references certain performance requirements in ASHRAE 90.1 and its published addenda for the Energy and Atmosphere category in the LEED building certification program.

The new ASHRAE standard increases insulation values across all seven climate zones within the United States, and in zones 5, 6 and 7 requires a base insulation material as well as rigid insulation board. This creates a significant market opportunity for insulated metal panel (IMP) manufacturers because it allows a building owner to select a readily available IMP panel to provide the required U-value, rather than specifying the more conventional wall insulation practices and materials.

For those who may be unfamiliar with them, IMPs are strong, single units constructed of a rigid polyurethane foam core sandwiched between two sheets of coated metal to provide an exceptionally strong and thermally efficient building enclosure. The durable metal panel facings resist damage and create a vapor and moisture barrier which offers long-term thermal stability. The metal skins also come in a multitude of colors and textures. When compared to other exterior finish options such as stucco, masonry or precast concrete, the IMP stands above the rest for its unique combination of impermeability, excellent thermal performance and visual appeal.

IMPs are installed outboard of the metal stud cavity or other support system, minimizing thermal short circuits. Their single-unit construction also eliminates the need for multiple components and other related construction trade coordination. In addition to being one of the first exterior wall systems to install insulation outside of the support system without compromising thermal performance, insulated metal panel systems are one of the few product choices to meet all the performance criteria with minimal compromise.

More information about IMP systems is available through the MCA at www.metalconstruction.org/imp.

Scott Kriner is a long-time member of the Metal Construction Association and currently serves as the group's Technical Director. He is also the president and founder of Green Metal Consulting Inc. He is a LEED Accredited Professional who began his career in the metal construction industry in 1981. His company is a member of the U.S. Green Building Council, the California Association of Building Energy Consultants and the Residential Energy Services Network (RESNET). Scott can be reached by email at skriner1@verizon.net, or by phone at (610) 966-2430.

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