Climate ZonesColoradoBoulder

Boulder, Colorado HVAC Climate Zone

Boulder is located in IECC Climate Zone 5B (Cool - Dry). Get accurate Manual J load calculations with official design temperatures for Boulder.

Climate Zone
5B
Winter Design
-7°F
Summer Design
91°F
ZIP Codes
16

Boulder HVAC Contractors: Get Your Free Manual J Report

Climate Zone 5B requires precise load calculations. Upload your Boulder blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Boulder's exact design temperatures (-7°F winter / 91°F summer).

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Verify Your Boulder ZIP Code

Enter your ZIP code to confirm it's in Boulder and get climate zone details.

Boulder covers 16 ZIP codes: 80301, 80302, 80303, 80304, 80305, 80025, 80026, 80027, 80455, 80466 and 6 more

Boulder Design Temperatures

Official ASHRAE design temperatures for Boulder, used for accurate Manual J load calculations.

Winter 99% Design Temp
-7°F
Summer 1% Design Temp
91°F
Summer Wet Bulb
63°F

IECC Requirements for Zone 5B

Minimum insulation and window requirements for Boulder per IECC 2021.

Wall Insulation:R-20
Roof/Ceiling:R-49
Floor Insulation:R-30
Window U-Factor:0.3
Window SHGC:0.4

Energy Code: 2021 IECC

Recommended HVAC Equipment for Boulder

Heating Systems

Gas furnace (95%+ AFUE)
Typical AFUE
95-98%

Cooling Systems

AC (13-15 SEER)
Typical SEER
13-15 SEER

Related Climate Zone Pages

Learn More About
Climate Zone 5B
View All Zones in
Colorado
HVAC Permits for
Boulder, Colorado

Get Free Manual J Calculations for Boulder

Upload your Boulder blueprint and get a professional Manual J load calculation using official Zone 5B design temperatures. First report is FREE.

Boulder design temps
Zone 5B compliant
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