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Energy Efficient Walls. Kelly Kissock, Ph.D., P.E. Department of Mechanical and Aerospace Engineering University of Dayton Industrial Assessment Center. Minimize Surface Area ACT 2 House. Effect of Framing Bridges on Interior Wall Temperatures. 2x4 and 2x6 Frame Walls.
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Energy Efficient Walls Kelly Kissock, Ph.D., P.E. Department of Mechanical and Aerospace Engineering University of Dayton Industrial Assessment Center
Truss and Beam with Wet-Blown Cellulose 1996 ASHRAE Technology Award
SIP Thermal Resistances Whole-wall effective R (hr-ft2-F/Btu) for 4.5-in SIP and frame walls
Strawbale Houses • Low embodied energy
Steel Framing • Steel conducts heat over 300 times faster than wood • Embodied Energy (2,000-square-foot house, EBN): • Steel: 53 mmBtu • Wood: 42 mmBtu • Use phase 48-92 mmBtu/yr (EPA) • Thermal resistance (JTM): • Rwood is 22% greater than Rsteel
ASHRAE Correction Factors for Metal Framing Example Correction Factor for wood framing ~ 0.90
Insulated / Uninsulated Walls Tint,ins = 74 F Tint,unins = 64 F
Closed-cell Polyurethane Spray-on Foam Insulation • All closed-cell polyurethane foam insulation made today is produced with a non-CFC (chlorofluorocarbon) gas as the foaming agent. • PU foam is • water-vapor permeable • remains flexible • fire resistant • provides good air sealing • R-3.6 to R-6.5 per inch thickness • Soy-based, polyurethane liquid spray-foamalso available.