Zone 3BWarm (Zone 3)
Climate Zone 3B - Warm, Dry
Warm summers with low humidity. Cool winters requiring moderate heating. This climate zone encompasses parts of California, Texas, Oklahoma, New Mexico and includes major cities like Fresno, Austin, San Antonio, Lubbock.
Design Temperatures
Winter Design Temperatures
15°F to 30°F
Used for heating load calculations and equipment sizing
Summer Design Temperatures
85°F to 95°F
Used for cooling load calculations and equipment sizing
Heating & Cooling Degree Days
Heating Degree Days (HDD)
2,000 - 3,500
Base 65°F. Higher numbers indicate more heating requirements and longer heating seasons.
Cooling Degree Days (CDD)
1,000 - 2,500
Base 65°F. Higher numbers indicate more cooling requirements and longer cooling seasons.
HVAC System Considerations
Key Considerations
- •Moderate cooling loads
- •Heating needs in winter
- •Low humidity year-round
- •Temperature swings
- •Dust considerations
Common Equipment
- ✓Heat pumps
- ✓Gas furnaces with AC
- ✓Packaged units
- ✓Evaporative cooling (supplemental)
Energy Code Requirements
Equipment Efficiency
- ⚠SEER 13+ minimum
- ⚠HSPF 7.7+ for heat pumps
- ⚠AFUE 78+ for furnaces
- ⚠Window U-factor limits
Insulation Requirements
Walls:R-13 to R-15
Ceiling:R-30 to R-38
Floor:R-19 to R-25
Major Cities in Zone 3B
States with Zone 3B Areas
Quick Reference
Zone:3B
Temperature:Warm
Moisture:Dry (B)
States:4
Cities:5
Calculate Load
Use our load calculators with the design temperatures and requirements specific to Zone 3B.