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.
Common Questions About Zone 4B
Zone 4B definition
This page explains what IECC climate zone 4B means in HVAC and building-code terms.
Cities in zone 4B
Use the city examples below to answer common lookup searches for this zone.
Heating and cooling profile
See whether zone 4B is heating-dominant, cooling-dominant, or balanced.
HVAC requirements
Compare design temperatures, degree days, code requirements, and equipment guidance for this zone.
What IECC Climate Zone 4B Means
Temperature class
Mixed (Zone 4)
Moisture class
Dry (B)
Load priority
Heating-dominant
Quick definition
Hot summers and cold winters with low humidity. Large temperature variations.
Common City Lookups for Zone 4B
| City | IECC zone answer | Why it matters |
|---|---|---|
| Denver | Denver is commonly treated as IECC climate zone 4B in this guide. | High heating loads |
| Colorado Springs | Colorado Springs is commonly treated as IECC climate zone 4B in this guide. | High heating loads |
| Albuquerque | Albuquerque is commonly treated as IECC climate zone 4B in this guide. | High heating loads |
| Oklahoma City | Oklahoma City is commonly treated as IECC climate zone 4B in this guide. | High heating loads |
| Wichita | Wichita is commonly treated as IECC climate zone 4B in this guide. | High heating loads |
Design Temperatures
Winter Design Temperatures
Used for heating load calculations and equipment sizing
Summer Design Temperatures
Used for cooling load calculations and equipment sizing
Heating & Cooling Degree Days
Heating Degree Days (HDD)
Base 65°F. Higher numbers indicate more heating requirements and longer heating seasons.
Cooling Degree Days (CDD)
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
Major Cities in Zone 4B
States with Zone 4B Areas
Quick Reference
Calculate Load
Use our load calculators with the design temperatures and requirements specific to Zone 4B.