Zone 5BCool (Zone 5)

Climate Zone 5B - Cool, Dry

Warm summers and cold winters with low humidity. High heating loads. This climate zone encompasses parts of Colorado, Wyoming, Utah, Nevada and includes major cities like Denver, Salt Lake City, Cheyenne, Reno.

Common Questions About Zone 5B

Zone 5B definition

This page explains what IECC climate zone 5B means in HVAC and building-code terms.

Cities in zone 5B

Use the city examples below to answer common lookup searches for this zone.

Heating and cooling profile

See whether zone 5B 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 5B Means

Temperature class

Cool (Zone 5)

Moisture class

Dry (B)

Load priority

Heating-dominant

Quick definition

Warm summers and cold winters with low humidity. High heating loads.

Common City Lookups for Zone 5B

CityIECC zone answerWhy it matters
DenverDenver is commonly treated as IECC climate zone 5B in this guide.Very high heating loads
Salt Lake CitySalt Lake City is commonly treated as IECC climate zone 5B in this guide.Very high heating loads
CheyenneCheyenne is commonly treated as IECC climate zone 5B in this guide.Very high heating loads
RenoReno is commonly treated as IECC climate zone 5B in this guide.Very high heating loads

Design Temperatures

Winter Design Temperatures

-5°F to 15°F

Used for heating load calculations and equipment sizing

Summer Design Temperatures

80°F to 90°F

Used for cooling load calculations and equipment sizing

Heating & Cooling Degree Days

Heating Degree Days (HDD)

4,500 - 7,000

Base 65°F. Higher numbers indicate more heating requirements and longer heating seasons.

Cooling Degree Days (CDD)

250 - 1,000

Base 65°F. Higher numbers indicate more cooling requirements and longer cooling seasons.

HVAC System Considerations

Key Considerations

  • Very high heating loads
  • Limited cooling needs
  • Altitude effects
  • Large temperature swings
  • Equipment derating

Common Equipment

  • High-efficiency gas furnaces
  • Boilers
  • Heat pumps (cold climate)
  • Radiant heating

Energy Code Requirements

Equipment Efficiency

  • SEER 13+ minimum
  • HSPF 8.2+ for heat pumps
  • AFUE 90+ for furnaces
  • High-performance building envelope

Insulation Requirements

Walls:R-19 to R-21
Ceiling:R-49 to R-60
Floor:R-25 to R-30

Major Cities in Zone 5B

States with Zone 5B Areas

Quick Reference

Zone:5B
Temperature:Cool
Moisture:Dry (B)
States:4
Cities:4

Calculate Load

Use our load calculators with the design temperatures and requirements specific to Zone 5B.