Spray Foam Professional - Fall 2012 - (Page 30)

MILITARY STANDARDS MILITARY STANDARDS AND SPRAY POLYURETHANE FOAM INSULATION PART 2 BY HUNTSMAN POLYURETHANES This article is Part 2 of a two-part series focused on SPF uses by the United State Military. See Part 1 here: www.naylornetwork.com/spfa ENERGY EFFICIENCY AND THE U.S. MILITARY UNCONTROLLED AIR MOVEMENT According to the Air Barrier Association of America (ABAA), uncontrolled air leakage in a building accounts for approximately 40 percent of heating and cooling energy usage. Even small gaps or holes in a building will allow unconditioned outside air to move freely through the building, making the space uncomfortable and increasing the load on the HVAC system. An air barrier system in the building envelope, or shell of the structure, is the primary mechanism used to control unwanted air movement into and out of the building. Simply put, an air barrier is used to control the flow of air between the outside and inside. An air barrier can be made from many different types of materials, but to be effective it must be installed properly and provide a complete shield around all sides of the building (i.e., the building envelope). When installed in a building, the air barrier material becomes part of an air barrier system, which is the combination of the air barrier material and all other components in the building – windows, doors and design features. The primary objective of the air barrier system is to block the random movement of air through building cavities. There are three key attributes to a well-designed and successfully-installed air barrier system. An air barrier must: • Be impermeable to air flow • Have sufficient durability over the expected lifetime of the building and 30 SPRAYFOAM PROFESSIONAL | Fall 2012 not easily be damaged or compromised during the construction process • Provide continuous coverage around the entire building from the roofi ng system to the below-grade structure An improperly-installed, poorlysealed or incomplete air barrier can effectively negate insulation and other energy saving devices in the building. To ensure that the high-energy efficiency and indoor air quality standards were met, the U.S. Army Corps of Engineers instituted a stringent validation process for new and retrofit construction projects that includes a blower door test and thermographic testing for air leakage. Also part of the validation process is the requirement that the building enclosure have a continuous air barrier system to control air leakage into or out of the conditioned space. Specifically, the U.S. Army Corps of Engineers directed that an acceptable air barrier system have the following characteristics: • It must be continuous with all joints sealed • It must be structurally supported to withstand positive and negative air pressures applied to the building enclosure • Connection shall be made between: – Foundation and walls – Walls and windows – Walls and doors – Different wall systems – Walls and roof – Walls and roof over unconditioned space – Walls, floors, and roofs across construction, control and expansion joints – Walls, floors, and roofs to utility, pipe and duct penetrations To help drive the usage of robust air barrier systems, the U.S. Army Corps of Engineers require a whole building test for air leakage with a maximum building envelope air leakage rate of 0.25/ CFM/sq.ft.2 at a pressure differential of 0.3 iwg (75 Pa). This testing is required by the Engineering and Construction Bulletin No. 2009-29 issued by the U.S. Army Corps of Engineers on building air tightness requirements. Selecting air barrier materials that will stop the flow of air from the outside into the structure and the flow of conditioned air from inside the structure to the outside is critical in order to reduce energy consumption. While traditional air barrier materials – house wrap, polyethylene and rigid sheathing materials, including gypsum and plywood – were once acceptable to use, the more stringent requirements for air barriers renders many of these materials troublesome, if the fi nal goal is to significantly reduce energy consumption. Creating a complete and unbroken air barrier system using traditional air barrier materials is difficult and often impossible in structures that are of a unique design or shape. SPF AS AN AIR BARRIER As an air barrier material, SPF offers many advantages over traditional insulations. Air barrier materials and assemblies are tested for their air permeance, or the volume of air that passes through the test specimen. Testing for permeance is done to standards established by the American Society for Testing and Materials (ASTM). Based upon the results of the test, air barrier materials and assemblies are assigned an air leakage rating. The baseline for an effective air barrier material is not to exceed 0.02L/ (s•m2) @ 75Pa. (0.004 cfm/ft2 @ 1.57 psf) per E2178 ASTM. When evaluated for air permeability, both open and http://www.naylornetwork.com/spfa http://www.sprayfoam.org

Table of Contents for the Digital Edition of Spray Foam Professional - Fall 2012

EXECUTIVE DIRECTOR’S CORNER
PRESIDENT’S POST
FOAM BUSINESS NEWS
SPFA TODAY
ABAA NEWS
LEGISLATIVE UPDATE
SAFETY FIRST
BEHIND THE FOAM
2012 SPFA CONTRACTOR AWARDS
GETTING SUSTAINABLE ROOFING RIGHT
MILITARY STANDARDS AND SPRAY POLYURETHANE FOAM INSULATION – PART 2
IRAQ – U.S. MILITARY IN IRAQ BENEFITS FROM PERFORMANCE OF SPF
ASK THE EXPERT
UPCOMING EVENTS
INDEX OF ADVERTISERS/ADVERTISERS.COM

Spray Foam Professional - Fall 2012

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