Calculate the annual heat loss (in U.S. units) through the following wall assemblies using U-factors from Table 2.9 and the annual heating degree days over a typical heating season at the geographical location where you reside. Base your analysis on 1000 ft² of wall area.
a. 2 × 4 wood-framed wall with R-11 insulation
b. 2 × 6 wood-framed wall with R-19 insulation
c. 8 in concrete uninsulated wall
d. 8 in solid brick uninsulated wall
e. 8 in concrete masonry unit (CMU) wall, with perliteinsulated cores
f. 14 in thick uninsulated adobe wall
g. 16 in solid log wall
h. 23 in straw bale wall
i. 31⁄2 in structural insulated panel (SIP) with EPS core wall

Table 2.9

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Wall Type Conventional Construction Wood Frame 2 x 4 (38 mm x 88 mm) wall w/ R-11 (RSI-1.9) insulation 2 x 6 (38 mm x 140 mm) wall w/ R-19 (RSI-3.3) insulation Light-Gauge Steel Frame 2 x 4 (38 mm x 88 mm) wall w/ R-11 (RSI-1.9) insulation 2 x 6 (38 mm x 140 mm) wall w/ R-19 (RSI-3.3) insulation Concrete 8 in (200 mm) standard weight uninsulated wall 12 in (200 mm) standard weight uninsulated wall Masonry 8 in (200 mm) solid brick uninsulated wall 12 in (200 mm) solid brick uninsulated wall 8 in (200 mm) CMU uninsulated wall 12 in (200 mm) CMU uninsulated wall 8 in (200 mm) CMU wall, perlite insulated cores 12 in (200 mm) CMU wall, perlite insulated cores hr. ft². °F Btu 10.2 15.4 7.5 9.1 1.5 1.6 2.4 3.2 2.0 2.1 5.5 7.9 R-Value °C m² W 1.8 2.7 1.3 1.6 0.3 0.3 0.4 0.6 0.4 0.4 1.0 1.4 Btu hr. ft² . °F 0.098 0.065 0.133 0.110 0.667 0.625 U-Factor 0.417 0.313 0.500 0.476 0.182 0.127 W °C. m² 0.557 0.369 0.761 0.627 3.786 3.549 2.366 1.775 2.839 2.704 1.032 0.719