North Dakota spans 2 IECC climate zones. Find your exact zone, design temperatures, and get free Manual J load calculations for any North Dakota location.
North Dakota spans 2 IECC climate zones (Zone 6A, Zone 7), which means insulation requirements, design temperatures, and equipment specs vary significantly depending on location. The primary zone, Zone 6A (Cold - Humid), is heating-dominated, with winter design temperatures as low as -9°F and summer highs reaching 89°F. HVAC contractors working across North Dakota need to verify the exact climate zone for each job site — using the wrong zone data leads to oversized or undersized equipment, failed inspections, and unhappy homeowners.
Minimum insulation R-values and window specifications required by the 2021 International Energy Conservation Code for North Dakota.
| Component | Zone 6A | Zone 7 |
|---|---|---|
| Ceiling / Attic | R-49 | R-60 |
| Walls | R-20 | R-20 |
| Floor | R-30 | R-38 |
| Window U-Factor | 0.3 | 0.3 |
| Window SHGC | 0.4 | 0.45 |
Source: IECC 2021 Table R402.1.2. Requirements shown are for residential construction. North Dakota contractors must use the zone that corresponds to the job site location.
These ASHRAE design temperatures determine how Manual J load calculations size heating and cooling equipment for North Dakota homes. The winter 99% value represents the coldest temperature expected, while the summer 1% value represents the hottest.
Cold - Humid
Very Cold
Based on Climate Zone 6A (Cold - Humid), here are typical HVAC equipment specifications for North Dakota installations.
Annual Fuel Utilization Efficiency for North Dakota furnaces
Seasonal Energy Efficiency Ratio for North Dakota AC systems
North Dakota's climate zone data ensures proper equipment sizing. No more callbacks from oversized or undersized systems.
North Dakota building departments require IECC-compliant Manual J calculations. Our tool uses official North Dakota climate data.
Right-sized systems based on North Dakota climate data reduce energy costs for homeowners and improve your reputation.
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