The thermal performance of steel-framed walls

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:211840

Barbour, C E ^[1]; Goodrow, J ^[2]

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1. NAHB Research Center, Upper Marlboro, MD (United States). Building Systems Div.
2. Holometrix, Bedford, MA (United States)

Thermal bridges are areas in constructions that have highly conductive materials, allowing higher heat transfer through less conductive areas. In a wall, thermal bridges can increase heat loss, cause dust to accumulate on the studs (ghosting) due to temperature distribution, and cause condensation to form in and on the walls. The effects of thermal bridges are often misunderstood by engineers, buildings, and manufacturers of construction products. This study attempts to provide a better understanding of the effects of thermal bridges in steel-framed walls, as well as information leading to improved methods of predicting R-value of walls containing thermal bridges. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them the freedom to correctly choose the optimum choice for construction. In order to arrive at an improved method, experimental data on the heat transfer characteristics of steel-framed walls were collected. Twenty-three wall samples were tested in a calibrated hot box (ASTM C976) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing, and fiberglass batt insulations. Other studies of thermal bridging in steel-framed walls have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Also, detailed monitoring of temperature gradients in the test walls combined with numerical analysis provided new insights into heat transfer phenomena concerning thermal bridges.

• OSTI ID: 211840
• Report Number(s): CONF-950624--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CONSTRUCTION
MATERIAL SUBSTITUTION
STEELS
TESTING
THERMAL CONDUCTIVITY
WALLS
WOOD