San Joaquin County is in IECC Climate Zone 3B (Warm - Dry). Get accurate Manual J load calculations with official ASHRAE design temperatures for San Joaquin County.
San Joaquin County, California is classified under IECC Climate Zone 3B (Warm - Dry), a mixed-climate region with dry moisture conditions. With 43 ZIP codes and 1 communities, every HVAC installation in San Joaquin County must use the ASHRAE design temperatures of 28°F (99% winter heating) and 102°F (1% summer cooling) for accurate Manual J load calculations.
With balanced heating and cooling loads, San Joaquin 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 3B in San Joaquin County, CA.
| 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 3B requires precise load calculations. Upload your San Joaquin County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with San Joaquin County's exact design temperatures (28°F winter / 102°F summer).
Enter your ZIP code to confirm it's in San Joaquin County and get climate zone details.
Official ASHRAE design temperatures for San Joaquin County, CA, used for accurate Manual J load calculations.
Minimum insulation and window requirements for San Joaquin County per IECC 2021 energy code.
Climate Zone 3B: Warm - Dry - Warm climate with low humidity, hot summers and cool winters. Moderate heating and cooling loads.
1 cities and communities in San Joaquin County share Climate Zone 3B requirements.
Compare climate zones with other counties in California. Different zones require different HVAC equipment sizing.
Upload your San Joaquin County blueprint and get a professional Manual J load calculation using official Zone 3B design temperatures. First report is FREE.
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