Climate zones from Figure C301.1 or Table C301.1 shall be used in determining the applicable requirements from Chapter 4.
|Key: A — Moist.|
|Asterisk (*) indicates a warm-humid location.|
|3A New Hanover*|
Deleted. Table C301.3(1) and Table C301.3(2) contain no NC requirements but are retained for information only.
|MAJOR CLIMATE TYPE DEFINITIONS|
|Marine (C) Definition—Locations meeting all four criteria:|
|1. Mean temperature of coldest month between -3°C (27°F) and 18°C (65°F).|
|2. Warmest month mean < 22°C (72°F).|
|3. At least four months with mean temperatures over 10°C (50°F).|
| 4. Dry season in summer. The month with the heaviest precipitation in the cold season has at least three times as much precipitation as the |
month with the least precipitation in the rest of the year. The cold season is October through March in the Northern Hemisphere and
April through September in the Southern Hemisphere.
|Dry (B) Definition—Locations meeting the following criteria:|
|Not marine and P in < 0.44 × (TF - 19.5) [Pcm < 2.0 × (TC + 7) in SI units]|
|P in = Annual precipitation in inches (cm)|
|T = Annual mean temperature in °F (°C)|
|Moist (A) Definition—Locations that are not marine and not dry.|
|Warm-humid Definition—Moist (A) locations where either of the following wet-bulb temperature conditions shall occur during the warmest six consecutive months of the year:|
|1. 67°F (19.4°C) or higher for 3,000 or more hours; or|
|2. 73°F (22.8°C) or higher for 1,500 or more hours.|
For SI: °C = [(°F)-32]/1.8, 1 inch = 2.54 cm.
| ZONE |
|IP Units||SI Units|
|1||9000 < CDD50°F||5000 < CDD10°C|
|2||6300 < CDD50°F ≤ 9000||3500 < CDD10°C ≤ 5000|
|3A and 3B||4500 < CDD50°F ≤ 6300 AND HDD65°F ≤ 5400||2500 < CDD10°C ≤ 3500 AND HDD18°C ≤ 3000|
|4A and 4B||CDD50°F ≤ 4500 AND HDD65°F ≤ 5400||CDD10°C ≤ 2500 AND HDD18°C ≤ 3000|
|3C||HDD65°F ≤ 3600||HDD18°C ≤ 2000|
|4C||3600 < HDD65°F ≤ 5400||2000 < HDD18°C ≤ 3000|
|5||5400 < HDD65°F ≤ 7200||3000 < HDD18°C ≤ 4000|
|6||7200 < HDD65°F ≤ 9000||4000 < HDD18°C ≤ 5000|
|7||9000 < HDD65°F ≤ 12600||5000 < HDD18°C ≤ 7000|
|8||12600 < HDD65°F||7000 < HDD18°C|
For SI: °C = [(°F)-32]/1.8.
The interior design temperatures used for heating and cooling load calculations shall be a maximum of 72°F (22°C) for heating and minimum of 75°F (24°C) for cooling.
Materials, systems and equipment shall be identified in a manner that will allow a determination of compliance with the applicable provisions of this code.
An R-value identification mark shall be applied by the manufacturer to each piece of building thermal envelope insulation 12 inches (305 mm) or greater in width. Alternately, the insulation installers shall provide a certification listing the type, manufacturer and R-value of insulation installed in each element of the building thermal envelope. For blown or sprayed insulation (fiberglass and cellulose), the initial installed thickness, settled thickness, settled R-value, installed density, coverage area and number of bags installed shall be listed on the certification. For sprayed polyurethane foam (SPF) insulation, the installed thickness of the areas covered and R-value of installed thickness shall be listed on the certification. For insulated siding, the R-value shall be labeled on the product's package and shall be listed on the certification. The insulation installer shall sign, date and post the certification in a conspicuous location on the job site.
The thickness of blown-in or sprayed roof/ceiling insulation (fiberglass or cellulose) shall be written in inches (mm) on markers that are installed at least one for every 300 square feet (28 m2) throughout the attic space. The markers shall be affixed to the trusses or joists and marked with the minimum initial installed thickness with numbers not less than 1 inch (25 mm) in height. Each marker shall face the attic access opening. Spray polyurethane foam thickness and installed R-value shall be listed on certification provided by the insulation installer.
Insulating materials shall be installed such that the manufacturer's R—value mark is readily observable upon inspection.
U-factors of fenestration products (windows, doors and skylights) shall be determined in accordance with NFRC 100. U-factors shall be determined by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled U-factor shall be assigned a default U-factor from Table C303.1.3(1) or C303.1.3(2). The solar heat gain coefficient (SHGC) and visible transmittance (VT) of glazed fenestration products (windows, glazed doors and skylights) shall be determined in accordance with NFRC 200 by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled SHGC or VT shall be assigned a default SHGC or VT from Table C303.1.3(3).
Exception: When a garage door is a part of the building thermal envelope, garage door U-factors shall be determined in accordance with either NFRC 100 or ANSI/DASMA 105.
|FRAME TYPE|| SINGLE |
| DOUBLE |
|Metal with Thermal Break||1.10||0.65||1.90||1.10|
|Nonmetal or Metal Clad||0.95||0.55||1.75||1.05|
| Insulated, nonmetal edge, max 45% glazing, |
any glazing double pane
|SINGLE GLAZED||DOUBLE GLAZED|| GLAZED |
The thermal resistance (R-value) of insulation shall be determined in accordance with the U.S. Federal Trade Commission R-value rule (CFR Title 16, Part 460) in units of h • ft2 • °F/Btu at a mean temperature of 75°F (24°C).
Materials, systems and equipment shall be installed in accordance with the manufacturer's instructions and the International Building Code.
Insulation applied to the exterior of basement walls, crawlspace walls and the perimeter of slab-on-grade floors shall have an opaque and weather-resistant protective covering to prevent the degradation of the insulation's thermal performance. The protective covering shall cover the exposed exterior insulation and extend not less than 6 inches (153 mm) below grade.
Maintenance instructions shall be furnished for equipment and systems that require preventive maintenance.