Coiling Doors Can Meet Building Envelope Code Requirements

It’s not an oxymoron!  Next generation coiling doors are more efficient than ever before.

Design professionals and building owners are increasingly demanding products that meet and exceed code requirements, particularly any requirements having to do with energy savings. The focus on “green” is becoming more widespread, leading to changes in regulations, codes, green building rating systems, and building products. Specifically, code authorities have highlighted that reducing air infiltration and improving insulation is critical for improving the performance of exterior  energy efficient garage doors.

First, a few definitions.  Air infiltration is defined as the unintended flow of air through cracks in the building envelope – particularly in and around window and door openings. Insulation is defined as a material’s resistance to conductive heat flow measured in terms of its thermal resistance. Code compliance can be defined in two ways when discussing energy savings: prescriptive and trade-off. The prescriptive compliance path means that a component must meet a specific level of performance. The trade-off compliance path allows for one component to fall short of the minimum level of performance that is outlined in the prescriptive path, but another component must “overperform” to offset the reduced level of performance of the other component. A trade-off is designed to allow trades to be made between various parts of the building envelope.  That said, a little-known fact is that this system of trade-offs is not allowed for air infiltration codes – all air infiltration codes must be met to the letter, no trade-offs allowed.

International Energy Conservation Code (IECC) 

T he International Energy Conservation Code was created to address the design of energy-efficient building envelopes and the installation of energy-efficient mechanical, lighting, and power systems through requirements emphasizing performance. This code establishes minimum regulations for energy-efficient buildings using prescriptive and performance-related provisions. Its impact is widespread - many state and local governments have already adopted the IECC. One area of particular interest to us is that its requirements reduce the allowable air infiltration rate for coiling doors. Section C402.5.2 requires that air infiltration for fenestration assemblies cannot exceed 1.00 cfm/ft², and section C402.1.3 requires an data-sf-ec-immutable="">of 4.75.

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ASHRAE (American Society of Heating, Refrigerating, and Air Conditioning Engineers)

The purpose of the ASHRAE 90.1 standard is to provide minimum requirements for the energy-efficient design of commercial buildings, including energy efficient garage doors. This standard also provides minimum requirements for the design and construction of new buildings and their systems, new portions of buildings and their systems, and new systems and equipment in existing buildings. It also provides criteria for determining compliance with these requirements. The provisions of this standard apply to the energy-efficiency of the building envelope, heating, ventilating, and air conditioning systems, service water heating, electric power distribution, motors and drives and lighting. ASHRAE 90.1 requires that air leakage for coiling doors cannot exceed an air leakage rate of 0.4 cfm/ft². Section 5.5.3.6 lists the prescriptive building envelope data-sf-ec-immutable="">of .31.

 
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