Charleston Climate Zone & Energy Code

Climate Zone: IECC Climate Zone 3A (mixed-humid). Charleston's coastal location produces high humidity year-round (94°F/79°F cooling design, 26°F heating design). Latent load management is critical — one of the most humidity-challenged markets in the Southeast.

Energy Code & Manual J Requirement: South Carolina Residential Energy Code (IECC 2009). ACCA Manual J required for all Charleston County and Lowcountry HVAC permit applications.

Local Electric Utility: Dominion Energy South Carolina

Building Department: City of Charleston Inspectional Services / Berkeley-Charleston-Dorchester Building Dept.

Local Trade Association: ACCA Carolina Chapter / ASHRAE Carolinas Chapter