Zone 4BMixed (Zone 4)
Climate Zone 4B - Mixed, Dry
Hot summers and cold winters with low humidity. Large temperature variations. This climate zone encompasses parts of Colorado, Kansas, Oklahoma, New Mexico, Utah and includes major cities like Denver, Colorado Springs, Albuquerque, Oklahoma City.
Design Temperatures
Winter Design Temperatures
5°F to 20°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)
3,500 - 6,000
Base 65°F. Higher numbers indicate more heating requirements and longer heating seasons.
Cooling Degree Days (CDD)
500 - 1,500
Base 65°F. Higher numbers indicate more cooling requirements and longer cooling seasons.
HVAC System Considerations
Key Considerations
- •High heating loads
- •Moderate cooling loads
- •Large temperature swings
- •Low humidity year-round
- •Altitude considerations
Common Equipment
- ✓Gas furnaces with AC
- ✓Heat pumps
- ✓Boilers with cooling
- ✓Evaporative cooling (supplemental)
Energy Code Requirements
Equipment Efficiency
- ⚠SEER 13+ minimum
- ⚠HSPF 7.7+ for heat pumps
- ⚠AFUE 78+ for furnaces
- ⚠Enhanced insulation requirements
Insulation Requirements
Walls:R-15 to R-19
Ceiling:R-38 to R-49
Floor:R-25 to R-30
Major Cities in Zone 4B
States with Zone 4B Areas
Quick Reference
Zone:4B
Temperature:Mixed
Moisture:Dry (B)
States:5
Cities:5
Calculate Load
Use our load calculators with the design temperatures and requirements specific to Zone 4B.