Imperial County is in IECC Climate Zone 2B (Hot - Dry). Get accurate Manual J load calculations with official ASHRAE design temperatures for Imperial County.
Imperial County, California is classified under IECC Climate Zone 2B (Hot - Dry), a cooling-dominated region with dry moisture conditions. With 17 ZIP codes and 1 communities, every HVAC installation in Imperial County must use the ASHRAE design temperatures of 33°F (99% winter heating) and 110°F (1% summer cooling) for accurate Manual J load calculations.
As a cooling-dominated zone, controlling solar heat gain is essential in Imperial County. Windows must have an SHGC of 0.25 or lower, along with R-13 wall and R-30 ceiling insulation. Proper sizing prevents oversized AC systems that short-cycle and waste energy.
Minimum insulation R-values and window performance for Climate Zone 2B in Imperial County, CA.
| Building Component | Minimum Requirement | Unit |
|---|---|---|
| Ceiling / Attic Insulation | R-30 | R-value |
| Wall Insulation | R-13 | R-value |
| Floor Insulation | R-13 | R-value |
| Window U-Factor | 0.4 | BTU/hr-ft²-°F |
| Window SHGC | 0.25 | Coefficient |
| Air Infiltration | 0.25 | ACH50 |
Climate Zone 2B requires precise load calculations. Upload your Imperial County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Imperial County's exact design temperatures (33°F winter / 110°F summer).
Enter your ZIP code to confirm it's in Imperial County and get climate zone details.
Official ASHRAE design temperatures for Imperial County, CA, used for accurate Manual J load calculations.
Minimum insulation and window requirements for Imperial County per IECC 2021 energy code.
Climate Zone 2B: Hot - Dry - Hot, dry climate with extreme summer heat and low humidity. Cool winters with minimal heating requirements.
1 cities and communities in Imperial County share Climate Zone 2B requirements.
Compare climate zones with other counties in California. Different zones require different HVAC equipment sizing.
Upload your Imperial County blueprint and get a professional Manual J load calculation using official Zone 2B design temperatures. First report is FREE.
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