Climate ZonesTexasCallahan

Callahan, Texas HVAC Climate Zone

Callahan is located in IECC Climate Zone 3B (Warm - Dry). Get accurate Manual J load calculations with official design temperatures for Callahan.

Climate Zone
3B
Winter Design
35°F
Summer Design
99°F
ZIP Codes
4

Callahan HVAC Contractors: Get Your Free Manual J Report

Climate Zone 3B requires precise load calculations. Upload your Callahan blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Callahan's exact design temperatures (35°F winter / 99°F summer).

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Verify Your Callahan ZIP Code

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

Callahan covers 4 ZIP codes: 76443, 76469, 79504, 79510

Callahan Design Temperatures

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

Winter 99% Design Temp
35°F
Summer 1% Design Temp
99°F
Summer Wet Bulb
68°F

IECC Requirements for Zone 3B

Minimum insulation and window requirements for Callahan per IECC 2021.

Wall Insulation:R-20
Roof/Ceiling:R-30
Floor Insulation:R-19
Window U-Factor:0.32
Window SHGC:0.25

Energy Code: 2021 IECC

Recommended HVAC Equipment for Callahan

Heating Systems

Gas furnace
Heat pump
Typical AFUE
90-95%

Cooling Systems

AC (14-16 SEER)
Typical SEER
14-16 SEER

Related Climate Zone Pages

Learn More About
Climate Zone 3B
View All Zones in
Texas
HVAC Permits for
Callahan, Texas

Get Free Manual J Calculations for Callahan

Upload your Callahan blueprint and get a professional Manual J load calculation using official Zone 3B design temperatures. First report is FREE.

Callahan design temps
Zone 3B compliant
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