ASHRAE-90.1-2022- - Page 280

Extracted Content

Table A9.4.2-2 Emittance Values of Various Surfaces and Effective Emittances of Air Spaces

Surface	Average Emissivity e	Effective Emissivity of Air Space	Col4
Surface	Average Emissivity****e	One Surface****e; Other, 0.9	Both Surfaces Emissivity****e
Aluminum foil, bright	0.05	0.05	0.03a
Metalized film, testedb	0.05	0.05	0.03a
Aluminum sheet	0.12	0.12	0.06
Aluminum coated paper, polished	0.20	0.20	0.11
Steel, galv., bright	0.25	0.24	0.14
Aluminum paint	0.50	0.47	0.32
Building materials: wood, paper, masonry, nonmetallic paints	0.90	0.82	0.82
Regular glass	0.84	0.77	0.72
a. When referencing Table A9.4.2-1, use an effective_emittance_ of 0.05. b. Tested_emittance_ in accordance with ASTM C1224 at 0.05 or less.	a. When referencing Table A9.4.2-1, use an effective_emittance_ of 0.05. b. Tested_emittance_ in accordance with ASTM C1224 at 0.05 or less.	a. When referencing Table A9.4.2-1, use an effective_emittance_ of 0.05. b. Tested_emittance_ in accordance with ASTM C1224 at 0.05 or less.	a. When referencing Table A9.4.2-1, use an effective_emittance_ of 0.05. b. Tested_emittance_ in accordance with ASTM C1224 at 0.05 or less.

Table A9.4.3 Effective R-Values for Fiberglass

Insulation R-Value at Standard Thickness

Rated R-Value	Col2	38	30	22	21	19	15	13	11
Standard Thickness, in.	Standard Thickness, in.	12	9.5	6.5	5.5	6	3.5	3.5	3.5
Nominal Lumber Size, in.	Actual Depth of Cavity, in.	Effective Insulation R-Values when Installed in a Confined Cavity	Effective Insulation R-Values when Installed in a Confined Cavity	Effective Insulation R-Values when Installed in a Confined Cavity	Effective Insulation R-Values when Installed in a Confined Cavity	Effective Insulation R-Values when Installed in a Confined Cavity	Effective Insulation R-Values when Installed in a Confined Cavity	Effective Insulation R-Values when Installed in a Confined Cavity	Effective Insulation R-Values when Installed in a Confined Cavity
2  12	11.25	37
2  10	9.25	32	30
2 8	7.25	27	26	22	21	19
2 6	5.5		21	20	21	18
2  4	3.5			14		13	15	13	11
2  4	2.5							9.8
2  4	1.5							6.3	6

278 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)