Climate ZonesTexasHouston

Houston, Texas HVAC Climate Zone

Houston is located in IECC Climate Zone 2A (Hot - Humid). Get accurate Manual J load calculations with official design temperatures for Houston.

Climate Zone
2A
Winter Design
32°F
Summer Design
95°F
ZIP Codes
99

Houston HVAC Contractors: Get Your Free Manual J Report

Climate Zone 2A requires precise load calculations. Upload your Houston blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Houston's exact design temperatures (32°F winter / 95°F summer).

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Verify Your Houston ZIP Code

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

Houston covers 99 ZIP codes: 77001, 77002, 77003, 77004, 77005, 77006, 77007, 77008, 77009, 77010 and 89 more

Houston Design Temperatures

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

Winter 99% Design Temp
32°F
Summer 1% Design Temp
95°F
Summer Wet Bulb
77°F

IECC Requirements for Zone 2A

Minimum insulation and window requirements for Houston per IECC 2021.

Wall Insulation:R-13
Roof/Ceiling:R-30
Floor Insulation:R-13
Window U-Factor:0.4
Window SHGC:0.25

Energy Code: 2021 IECC

Recommended HVAC Equipment for Houston

Heating Systems

Gas furnace
Heat pump
Electric resistance
Typical AFUE
80-92%

Cooling Systems

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

Related Climate Zone Pages

Learn More About
Climate Zone 2A
View All Zones in
Texas
HVAC Permits for
Houston, Texas

Get Free Manual J Calculations for Houston

Upload your Houston blueprint and get a professional Manual J load calculation using official Zone 2A design temperatures. First report is FREE.

Houston design temps
Zone 2A compliant
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