Nationwide HVAC Load Calculations — All 50 States

Areas We Serve

We provide residential Manual J, S, and D calculations for contractors, builders, architects, and homeowners across the entire United States — remotely, from your plans, with no site visit required.

Every state. Every climate zone. Same methodology.

The ACCA Manual J process is the same whether the project is in Miami or Minneapolis. The design conditions change — the rigor does not. Send us your plans from anywhere in the country and receive a permit-ready report in 24–48 hours.

IECC climate zone map of the United States showing zones 1 through 8 used for HVAC load calculations

IECC climate zones define the design conditions for every Manual J load calculation. A home in Zone 1A (hot-humid South Florida) and a home in Zone 6 (cold Minnesota) require fundamentally different calculations — and fundamentally different equipment.

Zone 1A — Hot-Humid Extreme cooling load, year-round humidity, minimal heating. Latent load dominates. Dehumidification is the primary sizing driver.

Miami Fort Lauderdale New Orleans Baton Rouge Shreveport Tampa Key West Corpus Christi Brownsville

Zone 2A — Hot-Humid Large cooling load with significant latent component. Real winter heating load. Two-season sizing required.

Orlando Jacksonville Houston San Antonio Montgomery Columbia SC Jackson MS Mobile Savannah Little Rock

Zone 3A — Warm-Humid Hot-humid summers with meaningful winter heating. The Southeast’s most common climate for new construction.

Atlanta Augusta Birmingham Dallas Fort Worth Nashville Memphis Raleigh Greensboro Charleston SC Charlotte Oklahoma City Tulsa Knoxville

Zone 3B — Hot-Dry Extreme sensible cooling load with low humidity. Large day-to-night temperature swings. Latent load is smaller but heating cannot be ignored.

Las Vegas Phoenix / Scottsdale Tucson El Paso Albuquerque Palm Springs Reno

Zones 4–8 — Mixed to Very Cold Heating-dominated climates where the winter load drives equipment selection. Cooling still matters in zones 4–5.

Washington DC (Zone 4A) Kansas City (Zone 4A) St. Louis (Zone 4A) Springfield MO (Zone 4A) Indianapolis (Zone 5A) Columbus (Zone 5A) Chicago (Zone 5A) Detroit (Zone 5A) Boston (Zone 5A) Denver (Zone 5B) Salt Lake City (Zone 5B) Portland OR (Zone 4C) Seattle (Zone 4C) Minneapolis (Zone 6A) Anchorage (Zone 7)

Our services — available everywhere

Manual J Load Calculation

Room-by-room heating and cooling loads using your actual design conditions. The foundation every equipment and duct decision is built on.

Learn about Manual J →

Manual S Equipment Selection

Equipment matched to real manufacturer performance at your design conditions — total, sensible, and latent capacity all verified.

Learn about Manual S →

Manual D Duct Design

Duct system sized to deliver the calculated airflow to every room — built from your plans, not a field estimate.

Learn about Manual D →

How remote HVAC load calculations work

Every project we run is done remotely — no site visit required, no local office needed. You send your plans, we model the home in WrightSoft Right-Suite Universal using ACCA Manual J methodology and your project’s actual design conditions, and we return a permit-ready PDF report. The process is the same whether the project is in Florida or Montana.

What we need from you: floor plans or dimensioned sketches, the project location, window and door details, insulation R-values, building orientation, and any known permit requirements. We confirm scope before work begins and deliver within 24–48 hours on most residential projects.

See our pricing page for rates, or send your plans directly to get started.

Nationwide service. Local design conditions. One standard of accuracy.

Permit-ready Manual J, S, and D reports for residential projects across all 50 states — in 24–48 hours.

See pricing and get started Send your plans