York County is in IECC Climate Zone 6A (Cold - Humid). Get accurate Manual J load calculations with official ASHRAE design temperatures for York County.
York County, Maine is classified under IECC Climate Zone 6A (Cold - Humid), a heating-dominated region with humid moisture conditions. With 42 ZIP codes and 1 communities, every HVAC installation in York County must use the ASHRAE design temperatures of 0°F (99% winter heating) and 86°F (1% summer cooling) for accurate Manual J load calculations.
As a heating-dominated zone, York County requires robust insulation — a minimum of R-20 in walls, R-49 in ceilings, and R-30 in floors. Windows must meet a U-factor of 0.3 or lower. These requirements ensure homes maintain comfort during the coldest 0°F design conditions.
Minimum insulation R-values and window performance for Climate Zone 6A in York County, ME.
| Building Component | Minimum Requirement | Unit |
|---|---|---|
| Ceiling / Attic Insulation | R-49 | R-value |
| Wall Insulation | R-20 | R-value |
| Floor Insulation | R-30 | R-value |
| Window U-Factor | 0.3 | BTU/hr-ft²-°F |
| Window SHGC | 0.4 | Coefficient |
| Air Infiltration | 0.15 | ACH50 |
Climate Zone 6A requires precise load calculations. Upload your York County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with York County's exact design temperatures (0°F winter / 86°F summer).
Enter your ZIP code to confirm it's in York County and get climate zone details.
Official ASHRAE design temperatures for York County, ME, used for accurate Manual J load calculations.
Minimum insulation and window requirements for York County per IECC 2021 energy code.
Climate Zone 6A: Cold - Humid - Cold climate with very cold winters and warm summers. Very high heating loads, moderate cooling needs.
1 cities and communities in York County share Climate Zone 6A requirements.
Compare climate zones with other counties in Maine. Different zones require different HVAC equipment sizing.
Upload your York County blueprint and get a professional Manual J load calculation using official Zone 6A design temperatures. First report is FREE.
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