Manual J calculator · GA
Manual J load calculation for Georgia.
Reference data for Manual J load calculations in Georgia: ASHRAE design temperatures for 4 top metros, energy code status, and SCILB / Conditioned Air licensing. The calculator does not load this page's data. It asks for your project location and looks up outdoor design conditions in its own dataset, by IECC 2021 climate zone for a ZIP code or by weather station for the 10 major metros in its city list.
Reference metro
Atlanta, GA (Fulton County) · IECC 2015 zone 3A · winter 99% DB 26°F · summer 0.4% DB 94°F · MCWB 74°F.
0.4% DB: ASHRAE 2021 station value · Manual J 8 loads use the 1% DB
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01 · ASHRAE design conditions
Top 4 metros in Georgia - ASHRAE design temperatures.
These are the ASHRAE 99% heating and 0.4% cooling design temperatures, not the absolute extremes. Outdoor temperatures go past the 0.4% cooling value about 35 hours per year and below the 99% heating value about 88 hours per year.
Manual J 8th edition load calculations use the 1% cooling and 99% heating design temperatures. For ENERGY STAR new homes, the EPA recommends "the ACCA Manual J, 8th edition, 1% cooling season design temperature and 99% heating season design temperature for the weather station that's geographically closest to the home" ( ENERGY STAR, Design Temperature Limits). For the same station the 1% cooling value is exceeded about 88 hours a year, against about 35 for the 0.4% value, so it is the lower of the two, and the table's cooling column is not the Manual J design temperature.
| Metro | County | Zone (IECC 2015) | Winter 99% DB | Summer 0.4% DB | MCWB |
|---|---|---|---|---|---|
| Atlanta | Fulton County | 3A | 26°F | 94°F | 74°F |
| Augusta | Richmond County | 3A | 26°F | 97°F | 76°F |
| Savannah | Chatham County | 2A | 31°F | 95°F | 78°F |
| Columbus | Muscogee County | 3A | 29°F | 96°F | 74°F |
Design temperatures are single station values from the ASHRAE 2021 Climatic Design Conditions (99% heating, 0.4% cooling), one airport station per metro, in whole °F within 1°F. DB = dry-bulb. MCWB = mean coincident wet-bulb at the 0.4% cooling design hour.
Zones in this table are from the IECC 2015 county map (PNNL county data). For a ZIP code, BuildSolver's calculator assigns zones by the IECC 2021 county map, which gives the same zones for these counties. A ZIP code near a zone line can get the neighboring zone.
02 · Energy code
Energy code baseline in Georgia is Georgia State Minimum Standard Energy Code (based on IECC 2015 with state amendments).
In effect since 2020. Manual J load-calc documentation requirements flow from the state energy code; verify your specific AHJ's submittal rules before relying on the baseline.
- Georgia's state minimum energy code is IECC 2015 with Georgia amendments, effective January 1, 2020; the Department of Community Affairs (DCA) administers the amendments.
- Local jurisdictions may adopt newer editions; the state amendments are baseline floors, not ceilings.
Code status from Georgia DCA - State Codes, verified August 20, 2024.
03 · Georgia HVAC labor data
BLS wages and employment for HVAC mechanics in Georgia.
These are state-level wages for occupation code 49-9021 - Heating, Air Conditioning, and Refrigeration Mechanics and Installers - from the most recent BLS Occupational Employment and Wage Statistics release.
- Median hourly wage
- $27.11
- Mean annual wage
- $57,080
- Employment estimate
- 12,290
Wage figures from BLS OEWS May 2025, SOC 49-9021 (state-level), released May 15, 2026.
04 · License & permit
HVAC licensing in Georgia runs through SCILB / Conditioned Air.
State-level HVAC contractor licensing is administered by the Georgia State Construction Industry Licensing Board - Division of Conditioned Air Contractors. Licenses renew every 2 years, with 8 hours of continuing education per cycle.
License types
- Conditioned Air Contractor - Class I (restricted: systems up to 175,000 BTU/hr heating and 60,000 BTU/hr cooling)
- Conditioned Air Contractor - Class II (unrestricted)
Permits
Georgia jurisdictions require a mechanical permit for HVAC installations and most change-outs. The state Conditioned Air Division licenses the contractor; the local AHJ issues the permit and conducts inspections.
A replacement install typically requires a permit as well.
Atlanta and most metro counties operate online permit portals; rural counties may require in-person filing. Conditioned Air license number is required on the permit application.
05 · FAQ
Common Manual J questions for Georgia contractors.
+Why is Atlanta a mixed-humid climate?
Atlanta sits in zone 3A - warm-humid mixed. The ASHRAE 0.4% summer DB is 94°F (Manual J 8th edition load calculations use the 1% dry-bulb, which for the same station is at or below it) with a 74°F mean coincident wet-bulb (significant latent load), but the 99% winter design DB drops to 26°F (real heating load). Manual J in zone 3A must balance cooling and heating equally; sensible-only sizing under-equips dehumidification, and heating-only sizing leaves the home uncomfortable in shoulder seasons.
+Does Georgia require Manual J for a residential permit?
Under the Georgia State Minimum Standard Energy Code, residential HVAC equipment must be sized per Manual J or equivalent. Requirements for the software and format vary by county. BuildSolver is not ACCA-approved for permit submission. Use its output for sales-phase sizing and client quotes, and produce the permit submittal in ACCA-approved software such as Wrightsoft Right-J8 or Cool Calc Manual J. Confirm with the county before submittal.
+What's the difference between Class I and Class II Conditioned Air?
Class I is the restricted license: systems up to 175,000 BTU/hr heating and 60,000 BTU/hr (5 tons) cooling, which covers most single-family work. Class II is unrestricted. Both require examination and 4 hours of continuing education per year.
+How does Savannah differ from Atlanta for Manual J?
Savannah is coastal zone 2A - warmer winters (31°F vs 26°F) and slightly higher summer wet-bulb (78°F vs 74°F). Manual J for Savannah will show higher latent share and lower heating load than Atlanta for the same building. Equipment sizing typically shifts toward heat-pump-only systems in Savannah, while Atlanta often justifies a gas furnace + AC pair.
+What's the average HVAC technician wage in Georgia?
BLS OEWS May 2025 (released May 15, 2026) reports a $27.11/hr median for Georgia HVAC mechanics and installers, with an annual mean of $57,080. The national median is $29.33/hr.
+Can BuildSolver size for a Georgia retrofit without blueprints?
Yes. BuildSolver's whole interface is built for the no-blueprint retrofit case - describe the building (square footage, construction type, window count, insulation level) and the tool runs the Manual J on those inputs. AutoHVAC requires blueprint PDFs; BuildSolver doesn't.
Try a Georgia load calculation now.
The chat will ask follow-up questions like an experienced engineer - square footage, construction type, window count, insulation level - and run the Manual J on your inputs. Outdoor design conditions come from its own dataset (by IECC 2021 climate zone for a ZIP code, by weather station for the 10 major metros in its city list), not from the metro table on this page.
Start Georgia calculationRelated · same climate zone
Other states with similar ASHRAE climate zones.
Climate-driven Manual J inputs such as infiltration, latent share, and design temperatures behave similarly across states that share a climate zone. Each page below gives that state's own design temperatures and licensing context. Zones combine the IECC 2015 and IECC 2021 county maps.
Data last reviewed October 16, 2026 · underlying sources as of May 15, 2026