We Do Load Calcs!
Fast Load Calculation Statewide Services
Achieving Optimal Energy Efficiency
HVAC Load Calculations Built to Your Climate Zone
Key Changes for 2026 Mechanical Designs:
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Lower Latent Capacity: Many new A2L-compatible coils have different moisture-removal profiles. In high-humidity zones like Florida (Zone 1), a mismatched Manual J can result in "wet" air and mold issues.
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Airflow Criticality: A2L systems often require specific airflow rates to ensure safety sensors don't trigger a shutdown. A precise Manual D (Duct Design) is mandatory to keep these systems running.
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Charge Limits: Building codes now limit the amount of refrigerant in a system based on the square footage of the room. If your load calculation is wrong and you install a system that is too large, you may technically be in violation of safety codes. (learn more)
Manual J, S, and D Load Calculations: U.S. Service Areas
Southeastern U.S. (Hot-Humid & Mixed-Humid)
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Florida: Miami, Tampa, Orlando, Jacksonville, Fort Lauderdale, Ft. Myers, Cape Coral, Boca Raton, Naples, Punta Gorda, Sarasota, Panama City Beach.
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Georgia: Atlanta, Augusta, Columbus, Decatur, Macon, Marietta, Savannah.
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Alabama: Birmingham, Huntsville, Mobile, Montgomery.
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The Carolinas: Charlotte, Raleigh, Greensboro, Asheville, Charleston (SC), Columbia, Greenville.
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Tennessee: Nashville, Memphis, Knoxville, Chattanooga.
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Deep South: New Orleans, Baton Rouge, Shreveport, Little Rock, Jackson (MS).
Northeastern & Mid-Atlantic U.S. (Cold & Mixed-Humid)
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New England: Boston, Worcester, Springfield (MA), Providence, Manchester, Burlington, Bridgeport, Hartford, New Haven, Stamford.
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Tri-State & Mid-Atlantic: New York City, Buffalo, Rochester, Albany, Newark, Jersey City, Paterson, Philadelphia, Pittsburgh, Allentown, Wilmington (DE), Baltimore.
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Virginia & WV: Virginia Beach, Richmond, Norfolk, Charleston (WV).
Midwestern U.S. (Cold & Extreme Cold)
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Great Lakes: Chicago, Detroit, Grand Rapids, Lansing, Cleveland, Columbus (OH), Cincinnati, Toledo, Milwaukee, Madison, Green Bay.
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Plains & Central: Indianapolis, Fort Wayne, Des Moines, Cedar Rapids, Wichita, Overland Park, Kansas City (MO/KS), St. Louis, Springfield (MO), Omaha, Lincoln, Fargo, Bismarck, Sioux Falls, Rapid City.
Western & Mountain U.S. (Arid, Marine, & High Altitude)
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California: Los Angeles, San Francisco, San Diego, San Jose, Sacramento, Fresno.
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Mountain: Denver, Colorado Springs, Aurora, Boise, Billings, Cheyenne, Salt Lake City, Albuquerque, Santa Fe.
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Southwest: Phoenix, Tucson, Mesa, Las Vegas, Reno, El Paso.
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Pacific Northwest: Seattle, Spokane, Tacoma, Portland (OR), Eugene, Salem.
Let's Get Started!
- Email your floor plans, blueprints, or sketches to info@loadcalculationshvac.com
Or, use our HVAC pricing calculator and get your instant quote to start right away!
Our HVAC design experts carefully analyze every detail to ensure accurate Manual J load calculations and precise Manual D ductwork layouts. Without this critical step, costly mistakes can result in poor airflow, energy waste, and uncomfortable temperature imbalances. Therefore, by providing your drawings, you guarantee a properly sized, high-performance HVAC system that maximizes efficiency and comfort. Additionally, our expert-designed solutions help lower energy bills, extend equipment lifespan, and prevent future HVAC issues. Moreover, we optimize your system for peak performance using the latest industry standards and best practices. As a result, you receive a customized HVAC design tailored to your home’s unique needs. So, don’t leave your heating and cooling to guesswork—email us your drawings today for a professional design solution. Finally, this simple process saves you time, money, and long-term headaches while ensuring total home comfort!
Every design is tailored to your specific IECC Climate Zone to ensure peak performance in regional climates.
Fast Turn Around Time
Get your Load Calcs in record time, accurately produced and code compliant.
Code Compliant
Our Manual J, D, S are ACCA Code Compliant & ready for inspection!
Licensed Designers
Over 35+ Heating and Air Expertise in the Field. Specializing in HVAC Systems Designs.
Led by our design team bringing over 35 years of boots-on-the-ground HVAC experience to every project. Unlike "online-only" calculators, we are licensed Mechanical Contractors who have spent decades in the field installing, maintaining, and engineering high-performance systems across the United States.
Our expertise isn't just theoretical—we hold active Mechanical Contractor Licenses in Florida, Georgia, Alabama, North Carolina, and South Carolina. This deep regional knowledge allows us to navigate the strict 5th and 6th Edition Energy Conservation Codes that other firms often overlook.
As active members of ACCA and ASHRAE, we stay at the forefront of the industry’s shift toward A2L Refrigerants and high-efficiency inverter technologies. Whether you are a homeowner in Florida, Dallas, or a contractor in Louisiana, Georgia, we ensure your Manual J, S, and D reports are technically flawless, permit-ready, and optimized for your specific climate zone.
We service Statewide with Fast Turnaround
Learn more about Manual J, Manual D, and Manual S
Manual J Service
A proper Manual J HVAC load calculation and duct design not only ensures your home runs efficiently
Manual S (Equipment Selection)
Manual S contains detailed technical and operational specifications on many different brands of HVAC systems
Learn More
Manual D (Duct Design)
Beyond Manual J load calculations, we also specialize in customized Manual D Duct Design for new construction and remodels.
Achieve Optimal Energy Efficiency at HVAC Load Calculations
1. MANUAL "J" LOAD CALC
A Manual J load calculation determines a home's heating and cooling needs based on precise factors. First, it analyzes square footage, insulation, windows, and climate to calculate heat gain and loss. Then, it considers occupancy, appliances, and airflow to refine the results. Next, the data helps select the right HVAC size for maximum efficiency. Without it, an oversized unit short cycles, causing humidity issues and wasted energy. Conversely, an undersized system struggles, leading to discomfort and higher bills. Therefore, a Manual J calculation ensures comfort, efficiency, and cost savings. Finally, professional HVAC design prevents future problems and extends system lifespan.
2. MANUAL "S" EQUIPMENT SELECTION
A Manual S equipment selection ensures the chosen HVAC system matches the Manual J load calculation results. First, it considers heating and cooling capacities to prevent inefficiency. Then, it factors in blower performance, fan speed, and manufacturer specifications. Without it, oversized units cycle poorly, while undersized ones struggle. Therefore, proper selection maximizes comfort, efficiency, and system longevity. Finally, a well-matched system reduces energy costs and prevents future performance issues
3. MANUAL "D" DUCT DESIGN
A Manual D duct design carefully ensures balanced airflow, leading to consistent heating and cooling throughout the home. First, it accurately calculates duct sizes based on Manual J, ensuring precise airflow distribution. Next, it thoroughly considers factors like friction loss, static pressure, and equipment compatibility to optimize performance. Without this critical step, poor airflow quickly leads to uncomfortable hot and cold spots. As a result, improper design reduces efficiency and shortens system lifespan. On the other hand, a properly designed system significantly improves comfort, efficiency, and long-term reliability. Furthermore, well-planned ducts help reduce noise, minimize energy waste, and lower maintenance costs. Ultimately, investing in professional duct design ensures a more efficient and comfortable home.
Why Precision Matters: Manual J vs. Rule of Thumb
| Feature | Rule of Thumb (Guesswork) | Manual J Precision (Our Service) |
| Sizing Basis | General Sq. Ft. (e.g., 500 sq ft per ton) | Insulation, Window U-Values, & Orientation |
| Climate Accuracy | Ignores local design temperatures | Uses exact IECC Climate Zone data |
| Humidity Control | Often oversized; leads to "cold and clammy" air | Optimized Latent Load removal for comfort |
| Equipment Life | Short-cycling leads to premature failure | Balanced cycles extend system longevity |
| Operating Cost | 20-30% higher due to inefficiency | Maximum energy savings and lower bills |
| Permit Ready | Often rejected by building departments | 100% ACCA Code Compliant and permit-ready |
Licensed. Certified. Accredited & 35+ Yrs of HVAC Design
We work closely with homeowners, builders, and architects to find cost-effective solutions while prioritizing energy efficiency. Because of our commitment, we consistently deliver exceptional results. We utilize Wrightsoft Software to ensure every Manual J heat gain/loss analysis is optimized for high-efficiency inverter systems and geothermal applications. Additionally, our extensive industry expertise ensures reliable and efficient solutions. Therefore, clients trust us to meet their unique needs with precision. The team's dedication sets us apart in the industry.