Nominal R-value | U-factor | |||
Floor | Perimeter | Post & Beam | Joists | |
0 | 0 11 19 30 | 0.112 0.100 0.098 0.093 | 0.134 0.116 0.114 0.107 | |
11 | 0 11 | 0.052 0.048 | 0.056 0.052 | |
19 | 0 11 | 0.038 0.036 | 0.041 0.038 | |
22 | 0 11 | 0.034 0.033 | 0.037 0.035 | |
25 | 0 11 | 0.032 0.031 | 0.034 0.033 | |
30 | 0 11 | 0.028 0.027 | 0.029 0.028 | |
38 | 0 11 | 0.024 0.024 | 0.025 0.024 |
Nominal R-value Perimeter | U-factor |
11 | 0.085 |
19 | 0.075 |
30 | 0.069 |
Note: | Crawlspaces used as heated plenums have approximately 30 percent higher heat loss rate than unvented crawlspaces with the same assumed ACH. Default U-factors in Table A105.1(2) reflect this higher rate of heat loss. |
Nominal R-value | U-factor | ||
Concrete | Wood Joist | Metal Joist | |
R-11 | 0.077 | 0.088 | 0.14 |
R-15 | 0.059 | 0.076 | 0.12 |
R-19 | 0.048 | 0.062 | 0.11 |
R-21 | 0.043 | 0.057 | 0.11 |
R-25 | 0.037 | 0.051 | 0.10 |
R-30 | 0.031 | 0.040 | 0.09 |
R-38 | 0.025 | 0.034 | 0.08 |