Russell County is in IECC Climate Zone 3A (Warm - Humid). Get accurate Manual J load calculations with official ASHRAE design temperatures for Russell County.
Russell County, Alabama is classified under IECC Climate Zone 3A (Warm - Humid), a mixed-climate region with humid moisture conditions. With 10 ZIP codes and 1 communities, every HVAC installation in Russell County must use the ASHRAE design temperatures of 24°F (99% winter heating) and 97°F (1% summer cooling) for accurate Manual J load calculations.
With balanced heating and cooling loads, Russell County homes require well-rounded insulation — R-20 walls, R-30 ceilings, R-19 floors — and windows with both U-factor 0.32 and SHGC 0.25 to handle both winter lows and summer highs.
Minimum insulation R-values and window performance for Climate Zone 3A in Russell County, AL.
| Building Component | Minimum Requirement | Unit |
|---|---|---|
| Ceiling / Attic Insulation | R-30 | R-value |
| Wall Insulation | R-20 | R-value |
| Floor Insulation | R-19 | R-value |
| Window U-Factor | 0.32 | BTU/hr-ft²-°F |
| Window SHGC | 0.25 | Coefficient |
| Air Infiltration | 0.15 | ACH50 |
Climate Zone 3A requires precise load calculations. Upload your Russell County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Russell County's exact design temperatures (24°F winter / 97°F summer).
Enter your ZIP code to confirm it's in Russell County and get climate zone details.
Official ASHRAE design temperatures for Russell County, AL, used for accurate Manual J load calculations.
Minimum insulation and window requirements for Russell County per IECC 2021 energy code.
Climate Zone 3A: Warm - Humid - Mixed climate with warm, humid summers and cool winters. Balanced heating and cooling needs.
1 cities and communities in Russell County share Climate Zone 3A requirements.
Compare climate zones with other counties in Alabama. Different zones require different HVAC equipment sizing.
Upload your Russell County blueprint and get a professional Manual J load calculation using official Zone 3A design temperatures. First report is FREE.
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