What Climate Zone is Glynn County, GA?

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

IECC Climate Zone
2A
Winter 99% Design
31°F
Summer 1% Design
94°F
ZIP Codes
8
Cities
1

Glynn County, Georgia is classified under IECC Climate Zone 2A (Hot - Humid), a cooling-dominated region with humid moisture conditions. With 8 ZIP codes and 1 communities, every HVAC installation in Glynn County must use the ASHRAE design temperatures of 31°F (99% winter heating) and 94°F (1% summer cooling) for accurate Manual J load calculations.

As a cooling-dominated zone, controlling solar heat gain is essential in Glynn 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.

Glynn County Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance for Climate Zone 2A in Glynn County, GA.

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

Glynn County HVAC Contractors: Get Your Free Manual J Report

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Verify Your Glynn County ZIP Code

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

Glynn County covers 8 ZIP codes including: 31520, 31521, 31522, 31523, 31524, 31525, 31527, 31561

Glynn County Design Temperatures

Official ASHRAE design temperatures for Glynn County, GA, used for accurate Manual J load calculations.

Winter 99% Design Temp
31°F
Heating load calculation baseline
Summer 1% Design Temp
94°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 Glynn 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 Glynn County, GA

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

Recommended HVAC Equipment for Glynn 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 Georgia

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

Get Free Manual J Calculations for Glynn County

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Glynn County design temps
Zone 2A compliant
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