Climate ZonesAlaskaNorth Slope County

What Climate Zone is North Slope County, AK?

North Slope County is in IECC Climate Zone 8 (Subarctic). Get accurate Manual J load calculations with official ASHRAE design temperatures for North Slope County.

IECC Climate Zone
8
Winter 99% Design
-42°F
Summer 1% Design
80°F
ZIP Codes
11
Cities
1

North Slope County, Alaska is classified under IECC Climate Zone 8 (Subarctic), a heating-dominated region with moist moisture conditions. With 11 ZIP codes and 1 communities, every HVAC installation in North Slope County must use the ASHRAE design temperatures of -42°F (99% winter heating) and 80°F (1% summer cooling) for accurate Manual J load calculations.

As a heating-dominated zone, North Slope County requires robust insulation — a minimum of R-20 in walls, R-60 in ceilings, and R-38 in floors. Windows must meet a U-factor of 0.3 or lower. These requirements ensure homes maintain comfort during the coldest -42°F design conditions.

North Slope County Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance for Climate Zone 8 in North Slope County, AK.

Building ComponentMinimum RequirementUnit
Ceiling / Attic InsulationR-60R-value
Wall InsulationR-20R-value
Floor InsulationR-38R-value
Window U-Factor0.3BTU/hr-ft²-°F
Window SHGC0.5Coefficient
Air Infiltration0.15ACH50

North Slope County HVAC Contractors: Get Your Free Manual J Report

Climate Zone 8 requires precise load calculations. Upload your North Slope County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with North Slope County's exact design temperatures (-42°F winter / 80°F summer).

Claim Free Report
No credit card required

Verify Your North Slope County ZIP Code

Enter your ZIP code to confirm it's in North Slope County and get climate zone details.

North Slope County covers 11 ZIP codes including: 99510, 99519, 99721, 99723, 99734, 99747, 99759, 99766 and 3 more

North Slope County Design Temperatures

Official ASHRAE design temperatures for North Slope County, AK, used for accurate Manual J load calculations.

Winter 99% Design Temp
-42°F
Heating load calculation baseline
Summer 1% Design Temp
80°F
Cooling load calculation baseline
Summer Wet Bulb
60°F
Latent load (humidity) calculation

IECC Zone 8 Insulation Requirements

Minimum insulation and window requirements for North Slope County per IECC 2021 energy code.

Wall Insulation:R-20
Roof/Ceiling:R-60
Floor Insulation:R-38
Window U-Factor:0.3
Window SHGC:0.5

Climate Zone 8: Subarctic - Subarctic climate with extreme cold. Maximum heating requirements, no cooling needed.

Cities in North Slope County, AK

1 cities and communities in North Slope County share Climate Zone 8 requirements.

Recommended HVAC Equipment for North Slope County

Heating Systems

Gas furnace (98%+ AFUE)
Boiler
Oil furnace
Typical AFUE
97-98.5%

Cooling Systems

Not typically needed

Get Free Manual J Calculations for North Slope County

Upload your North Slope County blueprint and get a professional Manual J load calculation using official Zone 8 design temperatures. First report is FREE.

North Slope County design temps
Zone 8 compliant
Ready in 60 seconds
Upload Blueprint - Get Free Report

Join 10,000+ Alaska contractors who trust AutoHVAC