Texas, Oklahoma HVAC Climate Zone

Texas is located in IECC Climate Zone 4B (Mixed - Dry). Get accurate Manual J load calculations with official design temperatures for Texas.

Climate Zone
4B
Winter Design
3°F
Summer Design
92°F
ZIP Codes
7

Texas HVAC Contractors: Get Your Free Manual J Report

Climate Zone 4B requires precise load calculations. Upload your Texas blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Texas's exact design temperatures (3°F winter / 92°F summer).

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Verify Your Texas ZIP Code

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

Texas covers 7 ZIP codes: 73901, 73939, 73942, 73944, 73945, 73949, 73951

Texas Design Temperatures

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

Winter 99% Design Temp
3°F
Summer 1% Design Temp
92°F
Summer Wet Bulb
62°F

IECC Requirements for Zone 4B

Minimum insulation and window requirements for Texas per IECC 2021.

Wall Insulation:R-20
Roof/Ceiling:R-49
Floor Insulation:R-19
Window U-Factor:0.32
Window SHGC:0.4

Energy Code: 2021 IECC

Recommended HVAC Equipment for Texas

Heating Systems

Gas furnace (92%+ AFUE)
Typical AFUE
92-96%

Cooling Systems

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

Get Free Manual J Calculations for Texas

Upload your Texas blueprint and get a professional Manual J load calculation using official Zone 4B design temperatures. First report is FREE.

Texas design temps
Zone 4B compliant
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