Climate ZonesLouisianaSt. Tammany County

What Climate Zone is St. Tammany County, LA?

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

IECC Climate Zone
2A
Winter 99% Design
28°F
Summer 1% Design
97°F
ZIP Codes
20
Cities
1

St. Tammany County, Louisiana is classified under IECC Climate Zone 2A (Hot - Humid), a cooling-dominated region with humid moisture conditions. With 20 ZIP codes and 1 communities, every HVAC installation in St. Tammany County must use the ASHRAE design temperatures of 28°F (99% winter heating) and 97°F (1% summer cooling) for accurate Manual J load calculations.

As a cooling-dominated zone, controlling solar heat gain is essential in St. Tammany County. Windows must have an SHGC of 0.25 or lower, along with R-13 wall and R-30 ceiling insulation. Proper sizing prevents oversized AC systems that short-cycle and waste energy.

St. Tammany County Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance for Climate Zone 2A in St. Tammany County, LA.

Building ComponentMinimum RequirementUnit
Ceiling / Attic InsulationR-30R-value
Wall InsulationR-13R-value
Floor InsulationR-13R-value
Window U-Factor0.4BTU/hr-ft²-°F
Window SHGC0.25Coefficient
Air Infiltration0.25ACH50

St. Tammany County HVAC Contractors: Get Your Free Manual J Report

Climate Zone 2A requires precise load calculations. Upload your St. Tammany County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with St. Tammany County's exact design temperatures (28°F winter / 97°F summer).

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Verify Your St. Tammany County ZIP Code

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

St. Tammany County covers 20 ZIP codes including: 70420, 70431, 70433, 70434, 70435, 70437, 70445, 70447 and 12 more

St. Tammany County Design Temperatures

Official ASHRAE design temperatures for St. Tammany County, LA, used for accurate Manual J load calculations.

Winter 99% Design Temp
28°F
Heating load calculation baseline
Summer 1% Design Temp
97°F
Cooling load calculation baseline
Summer Wet Bulb
77°F
Latent load (humidity) calculation

IECC Zone 2A Insulation Requirements

Minimum insulation and window requirements for St. Tammany County per IECC 2021 energy code.

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

Climate Zone 2A: Hot - Humid - Cooling-dominated with hot, humid summers and mild winters. Significant cooling loads with moderate heating needs.

Cities in St. Tammany County, LA

1 cities and communities in St. Tammany County share Climate Zone 2A requirements.

Recommended HVAC Equipment for St. Tammany County

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

Nearby Counties in Louisiana

Compare climate zones with other counties in Louisiana. Different zones require different HVAC equipment sizing.

Get Free Manual J Calculations for St. Tammany County

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St. Tammany County design temps
Zone 2A compliant
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