LoadCalc FL
Manual J / S / D · by Pineland Engineering
Calculate residential heating and cooling loads per ACCA Manual J 8th Ed. for all 67 Florida counties. Get equipment sizing (Manual S) and duct class (Manual D), then download a branded PDF of your results.
HVAC Load Results
Fill out the form and click Calculate HVAC Loads.
What Is Manual J?
ACCA Manual J (8th Ed.) is the industry standard for calculating residential heating and cooling loads. It defines how much heating and cooling capacity a home needs based on local climate, home size, construction materials, windows, and air infiltration.
In Florida, building departments require a stamped Manual J for HVAC permits on new construction. Manual J is also required for replacement systems in many counties. A correct Manual J prevents equipment oversizing, which is one of the most common problems with Florida HVAC systems.
Manual S — Equipment Sizing
ACCA Manual S specifies how to select HVAC equipment based on Manual J results. Cooling equipment must have a capacity between 95% and 115% of the calculated cooling load. Oversizing causes short-cycling, excessive humidity, and premature equipment wear.
Manual D — Duct Sizing
ACCA Manual D establishes procedures for designing air distribution (duct) systems. A properly sized duct system ensures each room receives the correct airflow, maximizing efficiency and comfort. In Florida, the FBC requires duct leakage not to exceed 4% of system airflow.
Why Florida Is Different
Florida has the most challenging climate for residential HVAC systems in the U.S. High humidity significantly increases the latent (moisture) load, which can represent 25–35% of the total cooling load. Solar loads through windows are extremely high. Winter is mild, so heating loads are minimal compared to cooling loads.
Get a Free QuoteManual J Florida FAQ
Is Manual J required in Florida?
Yes. The Florida Building Code requires Manual J load calculations for HVAC permits on new residential construction. Many counties also require it for replacement systems. Calculations must be stamped by a licensed Florida Professional Engineer (PE) or prepared by a certified HVAC contractor.
How much does a Manual J cost in Florida?
The cost of a stamped Manual J varies by project size and complexity. For typical residential homes, Pineland Engineering offers competitive pricing with fast turnaround. Request a free quote for your specific project.
How long does a Manual J take?
Pineland Engineering typically delivers stamped Manual J calculations within 2–5 business days for standard residential projects. Rush projects can be expedited. Contact us to discuss your project timeline.
What information is needed for a Manual J?
For a complete Manual J you need: floor plans with dimensions, construction specifications (wall type, insulation, windows), project location (county), building orientation, and the proposed HVAC system type. Pineland Engineering can work with preliminary plans.
What is the difference between Manual J, Manual S, and Manual D?
Manual J calculates the heating and cooling loads (how much capacity is needed). Manual S uses those loads to select the right equipment (what size unit to install). Manual D uses the equipment selection to design the duct system (how to distribute the air). All three are required for a complete HVAC design submittal in Florida.
Why is Manual J important in Florida's climate?
Florida's hot, humid climate makes proper load calculations especially critical. Oversized equipment is extremely common and causes short-cycling (the system turns on and off too frequently), poor humidity control, and premature equipment failure. A correct Manual J ensures the system runs long enough to properly dehumidify the air, which is essential for comfort and indoor air quality in Florida.