Description |
|
U-factor (Btu/ºF-ft²) |
A | ||
Uninsulated single-layer metal swinging doors or non-swinging doors, including single-layer uninsulated access hatches and uninsulated smoke vents: |
1 |
1.45 |
Uninsulated double-layer metal swinging doors or non-swinging doors, including double-layer uninsulated access hatches and uninsulated smoke vents: |
2 |
0.70 |
Insulated metal swinging doors, including fire-rated doors, insulated access hatches, and insulated smoke vents: |
3 |
0.50 |
Wood doors, minimum nominal thickness of 1-3/4 in. (44 mm), including panel doors with minimum panel thickness of 1-1/8 in. (28 mm), and solid core flush doors, and hollow core flush doors: |
4 |
0.50 |
Any other wood door: |
5 |
0.60 |
Uninsulated single layer metal roll up doors including fire rated door |
6 |
1.45 |
Insulated single layer metal sectional doors, minimum insulation nominal thickness of 1-3/8 inch; expanded polystyrene (R-4 per inch). |
7 |
0.179 |
Source: ASHRAE 90.1-2007, Section A7. |
Table 4.5.2 – Physical Properties of Materials
Code |
Description |
R-value |
Thickness |
Conductivity |
Density |
Specific Heat |
AR02 |
Asphalt Shingle & Siding |
0.44 |
|
|
70.0 |
0.35 |
BP01 |
Building Paper, Permeable Felt |
0.06 |
|
|
|
|
PW03 |
Plywood 1/2 in. |
0.63 |
0.0417 |
0.0667 |
34.0 |
0.29 |
GP01 |
Gypsum Board 1/2 in. |
0.45 |
0.0417 |
0.0926 |
50.0 |
0.26 |
BR01 |
Built-up Roofing 3/8 in. |
0.33 |
0.0313 |
0.0939 |
70.0 |
0.35 |
PW05 |
Plywood 3/4 in. |
0.94 |
0.0625 |
0.0667 |
34.0 |
0.29 |
PW04 |
Plywood 5/8 in. |
0.78 |
0.0521 |
0.0667 |
34.0 |
0.29 |
CP01 |
Carpet with Fibrous Pad |
2.08 |
|
|
|
0.34 |
PB01 |
Particle Board Low Density 3/4 in. |
1.39 |
0.0625 |
0.0450 |
75.0 |
0.31 |
SC01 |
Stucco 1 in. |
0.20 |
0.0833 |
0.4167 |
116.0 |
0.20 |
WD05 |
Wood, Soft 4 in. |
5.00 |
0.3333 |
0.0667 |
32.0 |
0.33 |
WD11 |
Wood, Hard 3/4 in. |
0.68 |
0.0625 |
0.0916 |
45.0 |
0.30 |
-CC03 |
Heavy Wt. Dried Aggregate 4 in. |
0.44 |
0.3333 |
0.7576 |
140.0 |
0.20 |
CC14 |
Heavy Wt. Undried Aggregate 4 in. |
0.32 |
0.3333 |
1.0417 |
140.0 |
0.20 |
AC02 |
1/2 in. Acoustic Tile |
1.26 |
0.0417 |
0.0330 |
18.0 |
0.32 |
AL33 |
Air Layer 4 in. or more, Horizontal Roof |
0.92 |
1.0000 |
0.4167 |
120.0 |
0.20 |
CP01 |
Carpet with Fibrous Pad |
2.08 |
|
|
|
0.34 |
Custom |
Concrete |
0.11 |
|
|
144.0 |
0.20 |
Custom |
Light Weight CMU |
0.35 |
|
|
105.0 |
0.20 |
Custom |
Medium Weight CMU |
0.35 |
|
|
115.0 |
0.20 |
Custom |
Normal Weight CMU |
0.35 |
|
|
125.0 |
0.20 |
Custom |
Earth (Soil) |
3.00 |
1.5000 |
0.5000 |
85.0 |
0.20 |
Custom |
Logs 6 in. |
7.50 |
0.5000 |
0.0667 |
32.0 |
0.33 |
Custom |
Logs 8 in. |
10.00 |
0.6667 |
0.0667 |
32.0 |
0.33 |
Custom |
Logs 10 in. |
12.49 |
0.8333 |
0.0667 |
32.0 |
0.33 |
Custom |
Logs 12 in. |
14.99 |
1.0000 |
0.0667 |
32.0 |
0.33 |
Custom |
Logs 14 in. |
17.49 |
1.1667 |
0.0667 |
32.0 |
0.33 |
Custom |
Logs 16 in. |
19.99 |
1.3333 |
0.0667 |
32.0 |
0.33 |
Custom |
Earth 12 in. |
2.00 |
1.0000 |
0.5000 |
85.0 |
0.20 |
Custom |
Vented crawlspace |
6.00 |
NA |
NA |
NA |
NA |
Custom |
7/8" layer of stucco of R-0.18 |
0.18 |
0.0729 |
0.4167 |
116.0 |
0.20 |
Custom |
Straw bale |
30.00 |
|
|
|
|
Custom |
Acoustic tile + Metal |
0.50 |
0.0417 |
0.0330 |
18.0 |
0.32 |
Custom |
OSB 7/16 in. |
0.44 |
0.4375 |
0.0667 |
34.0 |
0.29 |
Table 4.5.3 – Rules for Calculating Mass Thermal Properties From Published Values
Property |
Units |
Rule for Calculation |
Heat Capacity (HC) |
Btu/ºF-ft² |
From Table 4.3.5, Table 4.3.6, or Table 4.3.7 |
U-factor |
Btu/h-ºF-ft² |
From Table 4.3.5, Table 4.3.6, or Table 4.14 |
C-factor |
Btu/h-ºF-ft² |
From Table 4.3.5, Table 4.3.6, or Table 4.3.7 |
Thickness (T) |
Ft |
From Table 4.3.5, Table 4.3.6, or Table 4.3.7 |
Specific Heat (SH) |
Btu/ºF-lb |
Assume that the specific heat of all concrete and masonry materials is 0.20 Btu/ºF-lb and that the specific heat of wood or straw (see Table 4.3.11 and Table 4.3.12) is 0.39 Btu/ºF-lb. |
Weight (W) |
lb/ft² |
Divide the HC by the assumed specific heat. Wall weight is used with the low-rise residential standards to define a high mass wall. |
Density (D) |
lb/ft³ |
Multiply the weight (as calculated above) by the thickness (T) |
Conductivity (C) |
Btu/h-ºF-ft |
Divide the published C-factor by the thickness (T). When only a U-factor is published, calculate the C-factor by assuming an exterior air film of 0.17 and an interior air film of 0.68. |