Yolo County is in IECC Climate Zone 3B (Warm - Dry). Get accurate Manual J load calculations with official ASHRAE design temperatures for Yolo County.
Yolo County, California is classified under IECC Climate Zone 3B (Warm - Dry), a mixed-climate region with dry moisture conditions. With 21 ZIP codes and 1 communities, every HVAC installation in Yolo County must use the ASHRAE design temperatures of 28°F (99% winter heating) and 103°F (1% summer cooling) for accurate Manual J load calculations.
With balanced heating and cooling loads, Yolo 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 Yolo 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 Yolo County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Yolo County's exact design temperatures (28°F winter / 103°F summer).
Enter your ZIP code to confirm it's in Yolo County and get climate zone details.
Official ASHRAE design temperatures for Yolo County, CA, used for accurate Manual J load calculations.
Minimum insulation and window requirements for Yolo 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 Yolo County share Climate Zone 3B requirements.
Compare climate zones with other counties in California. Different zones require different HVAC equipment sizing.
Upload your Yolo County blueprint and get a professional Manual J load calculation using official Zone 3B design temperatures. First report is FREE.
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