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  • (This is a normative appendix and is part of this standard.)

    NORMATIVE APPENDIXA
    CLIMATE ZONES AND PRESCRIPTIVE BUILDING ENVELOPE AND DUCT INSULATION TABLES


    Tables A-1 through A-3 appear twice in this appendix. The three tables are shown first with I-P units, followed by three tables with SI units.

    For climate zones, see Section 5.1.4 of ANSI/ASHRAE/IES Standard 90.1 and Normative Appendix B of ANSI/ASHRAE Standard 169.

    1. a.For the United States, the ANSI/ASHRAE Standard 169 climate zone map is reproduced below. A list of counties and their respective climate zones can be found in Table B1 in ANSI/ASHRAE Standard 169.

    2. b.For Canada, see Table B2 in ANSI/ASHRAE Standard 169.

    3. c.For available international locations (outside the U.S. and Canada), see Table B3 in ANSI/ASHRAE Standard 169.

    4. d.For locations not provided in Tables B2 or B3, see Table B4 (reproduced below) in ANSI/ASHRAE Standard 169 for the international climate zone definitions.

    U.S. Climate Zone Map (ASHRAE Transactions 109(1), Briggs et al., 2003)

    Climate ZoneNumberNameThermal Criteria (I-P)Thermal Criteria (SI)
    1Very hot—Humid (1A), Dry (1B)9000 < CDD50°F5000 < CDD10°C
    2Hot—Humid (2A), Dry (2B)6300 < CDD50°F ≤ 90003500 < CDD10°C ≤ 5000
    3A, 3BWarm—Humid (3A), Dry (3B)4500 < CDD50°F ≤ 63002500 < CDD10°C ≤ 3500
    3CWarm—Marine (3C)CDD50°F ≤ 4500 and HDD65°F ≤ 3600CDD10°C ≤ 2500 and HDD18°C ≤ 2000
    4A, 4BMixed—Humid (4A), Dry (4B)CDD50°F ≤ 4500 and 3600 < HDD65°F ≤ 54002500 ≤ CDD10°C and 2000 < HDD18°C ≤ 3000
    4CMixed—Marine (4C)3600 < HDD65°F ≤ 54002000 < HDD18°C ≤ 3000
    5A, 5B, 5CCool—Humid (5A), Dry (5B), Marine (5C)5400 < HDD65°F ≤ 72003000 < HDD18°C ≤ 4000
    6A, 6BCold—Humid (6A), Dry (6B)7200 < HDD65°F ≤ 90004000 < HDD18°C ≤ 5000
    7Very cold9000 < HDD65°F ≤ 126005000 < HDD18°C ≤ 7000
    8Subarctic12600 < HDD65°F7000 < HDD18°C

    TABLE A-1 (Supersedes Table A2.4.2 in ANSI/ASHRAE/IES Standard 90.1)

    Single-Rafter Roof Requirements (I-P)

    Minimum Insulation R-Value or Maximum Assembly U-Factor
    Climate ZoneNonresidentialResidentialSemiheated
    1R-38 U-0.029R-38 + R10 ci U-0.022R-19 U-0.055
    2R-38 + R10 ci U-0.022R-38 + R10 ci U-0.022R-19 U-0.055
    3, 4, 5R-38 + R10 ci U-0.022R-38 + R10 ci U-0.022R-30 U-0.036
    6R-38 + R10 ci U-0.022R-38 + R10 ci U-0.022R-38 U-0.029
    7, 8R-38 + R15 ci U-0.020R-38 + R15 ci U-0.020R-38 U-0.029

    TABLE A-2 (Supersedes Table 6.8.2-1 in ANSI/ASHRAE/IES Standard 90.1)

    Minimum Duct Insulation R-Valuea Heating- and Cooling-Only Supply Ducts and Return Ducts (I-P)

    Duct Location
    ClimateZoneExteriorVentilated AtticUnvented Attic above Insulated CeilingUnvented Attic with Roof InsulationaUnconditioned SpacebIndirectly ConditionedSpacecBuried
    Heating-Only Ducts
    1, 2NoneNoneNoneNoneNoneNoneNone
    3R-6NoneNoneNoneR-6NoneNone
    4R.6NoneNoneNoneR-6NoneNone
    5R-8R-6NoneNoneR-6NoneR-6
    6R-8R-8R-6NoneR-6NoneR-6
    7R-10R-8R-8NoneR-6NoneR-6
    8R-10R-10R-8NoneR-8NoneR-8
    Cooling-Only Ducts
    1R-6R-8R-10R-6R-6NoneR-6
    2R-6R-8R-10R-6R-6NoneR-6
    3R-6R-8R-8R-6R-3.5NoneNone
    4R-3.5R-6R-8R-3.5R-3.5NoneNone
    5, 6R-3.5R-3.5R-6R-3.5R-3.5NoneNone
    7, 8R-1.9R-3.5R-3.5R-3.5R-3.5NoneNone
    Return Ducts
    1 to 8R-6R-6R-6NoneNoneNoneNone
    1. a.Insulation R-values, measured in (h·ft2·°F)/Btu, are for the insulation as installed and do not include film resistance. The required minimum thicknesses do not consider water vapor transmission and possible surface condensation. Where exterior walls are used as plenum walls, wall insulation shall be as required by the most restrictive condition of this table or Section 7.4.2. Insulation resistance measured on a horizontal plane in accordance with ASTM C518 at a mean temperature of 75°F at the installed thickness.

    2. b.Includes crawl spaces, both ventilated and nonventilated.

    3. c.Includes return air plenums with or without exposed roofs above.

    TABLE A-3 (Supersedes Table 6.8.2-2 in ANSI/ASHRAE/IES Standard 90.1)

    Minimum Duct Insulation R-Valuea Combined Heating and Cooling Supply Ducts and Return Ducts (I-P)

    Duct Location
    ClimateZoneExteriorVentilated AtticUnvented Atticabove InsulatedCeilingUnvented Attic with Roof InsulationaUnconditioned SpacebIndirectly Conditioned SpacecBuried
    Supply Ducts
    1R-8R-8R-10R-6R-6NoneR-6
    2R-8R-8R-8R-6R-8NoneR-6
    3R-8R-8R-8R-6R-8NoneR-6
    4R-8R-8R-8R-6R-8NoneR-6
    5R-8R-8R-8R-3.5R-8NoneR-6
    6R-10R-8R-8R-3.5R-8NoneR-6
    7R-10R-8R-8R-3.5R-8NoneR-6
    8R-10R11R11R-3.5R-8NoneR-8
    Return Ducts
    1 to 8R-6R-6R-6NoneNoneNoneNone
    1. a.Insulation R-values, measured in (h·ft2·°F)/Btu, are for the insulation as installed and do not include film resistance. The required minimum thicknesses do not consider water vapor transmission and possible surface condensation. Where exterior walls are used as plenum walls, wall insulation shall be as required by the most restrictive condition of this table or Section 7.4.2. Insulation resistance measured on a horizontal plane in accordance with ASTM C518 at a mean temperature of 75°F at the installed thickness.

    2. b.Includes crawl spaces, both ventilated and non-ventilated.

    3. c.Includes return air plenums with or without exposed roofs above.

    TABLE A-1 (Supersedes Table A2.4.2 in ANSI/ASHRAE/IES Standard 90.1)

    Single-Rafter Roof Requirements (SI)

    Minimum Insulation R-Value or Maximum Assembly U-Factor
    Climate ZoneNonresidentialResidentialSemiheated
    1R-6.7U-0.165R-6.7 + R-1.8 ciU-0.112R-3.3U-0.312
    2R-6.7 + R-1.8 ciU-0.112R-6.7 + R-1.8 ciU-0.112R-3.3U-0.312
    3, 4, 5R-6.7 + R-1.8 ciU-0.112R-6.7 + R-1.8 ciU-0.112R-5.3U-0.204
    6R-6.7 + R-1.8 ciU-0.112R-6.7 + R-1.8 ciU-0.112R-6.7U-0.165
    7, 8R-6.7 + R-2.6 ciU-0.111R-6.7 + R-2.6 ciU-0.111R-6.7U-0.165

    TABLE A-2 (Supersedes Table 6.8.2A in ANSI/ASHRAE/IES Standard 90.1)

    Minimum Duct Insulation R-Valuea Heating- and Cooling-Only Supply Ducts and Return Ducts (SI)

    Duct Location
    Climate ZoneExteriorVentilated AtticUnvented Attic Above InsulatedCeilingUnvented Attic with Roof InsulationaUnconditioned SpacebIndirectly Conditioned SpacecBuried
    Heating-Only Ducts
    1, 2NoneNoneNoneNoneNoneNoneNone
    3R-1.06NoneNoneNoneR-1.06NoneNone
    4R-1.06NoneNoneNoneR-1.06NoneNone
    5R-1.41R-1.06NoneNoneR 1.06NoneR-1.06
    6R-1.41R-1.41R-1.06NoneR 1.06NoneR-1.06
    7R-1.76R-1.41R-1.41NoneR-1.06NoneR-1.06
    8R-1.76R-10R-1.41NoneR-1.41NoneR-1.41
    Cooling-Only Ducts
    1R-1.06R-1.41R-10R-1.06R-1.06NoneR-1.06
    2R-1.06R-1.41R-10R-1.06R-1.06NoneR-1.06
    3R-1.06R-1.41R-1.41R-1.06R-0.62NoneNone
    4R-0.62R-1.06R-1.41R-0.62R-0.62NoneNone
    5, 6R-0.62R-0.62R-1.06R-0.62R-0.62NoneNone
    7, 8R-1.9R-0.62R-0.62R-0.62R-0.62NoneNone
    Return Ducts
    1 to 8R-1.06R-1.06R-1.06NoneNoneNoneNone
    1. a.Insulation R-values, measured in m2·k/kW, are for the insulation as installed and do not include film resistance. The required minimum thicknesses do not consider water vapor transmission and possible surface condensation. Where exterior walls are used as plenum walls, wall insulation shall be as required by the most restrictive condition of this table or Section 7.4.2. Insulation resistance measured on a horizontal plane in accordance with ASTM C518 at a mean temperature of 23.8 C at the installed thickness.

    2. b.Includes crawl spaces, both ventilated and non-ventilated.

    3. c.Includes return air plenums with or without exposed roofs above.

    TABLE A-3 (Supersedes Table 6.8.2A in ANSI/ASHRAE/IES Standard 90.1)

    Minimum Duct Insulation R-Valuea Combined Heating and Cooling Supply Ducts and Return Ducts (SI)

    Duct Location
    Climate ZoneExteriorVentilated AtticUnvented Attic above Insulated CeilingUnvented Attic with Roof InsulationaUnconditioned SpacebIndirectly Conditioned SpacecBuried
    Supply Ducts
    1R-1.41R-1.41R-1.76R-1.06R-1.06NoneR-1.06
    2R-1.41R-1.41R-1.41R-1.06R-1.41NoneR-1.06
    3R-1.41R-1.41R-1.41R-1.06R-1.41NoneR-1.06
    4R-1.41R-1.41R-1.41R-1.06R-1.41NoneR-1.06
    5R-1.41R-1.41R-1.41R-0.62R-1.41NoneR-1.06
    6R-1.76R-1.41R-1.41R-0.62R-1.41NoneR-1.06
    7R-1.76R-1.41R-1.41R-0.62R-1.41NoneR-1.06
    8R-1.76R-1.94R-1.94R-0.62R-1.41NoneR-1.41
    Return Ducts
    1 to 8R-1.06R-1.06R-1.06NoneNoneNoneNone
    1. a.Insulation R-values, measured in m2·k/kW, are for the insulation as installed and do not include film resistance. The required minimum thicknesses do not consider water vapor transmission and possible surface condensation. Where exterior walls are used as plenum walls, wall insulation shall be as required by the most restrictive condition of this table or Section 7.4.2. Insulation resistance measured on a horizontal plane in accordance with ASTM C518 at a mean temperature of 23.8 C at the installed thickness.”

    2. b.Includes crawl spaces, both ventilated and non-ventilated.

    3. c.Includes return air plenums with or without exposed roofs above.