Manual D Ductsize is residential HVAC duct sizing software that calculates optimal duct sizes and pressure losses in accordance with ACCA Manual D, supporting both round and rectangular ducts and multiple sizing methods for accurate, code-aligned design. It includes a fitting selector with drawings of hundreds of ACCA duct fittings, handles both supply and return systems in one project with automatic accounting of return-side losses, and supports virtually unlimited trunks and runouts for complex layouts. The program generates comprehensive color reports for printing, previewing, and saving, works with both conventional and high-velocity systems, and accepts English or metric units.

Key Features

ACCA Manual D-based sizing Automated, rule-compliant calculations.

• Calculates optimal duct sizes and pressure losses for residential systems.
• Supports round and rectangular ducts with four sizing methods: Nearest Inch, Exact, Use Schedule, and Presize.

Extensive fitting library Speeds accurate loss modeling.

• Fitting Selector shows drawings for hundreds of ACCA fittings.
• Applies fitting losses within supply and return networks in one model.

Large, flexible system modeling Scales to real projects.

• Virtually unlimited trunks and runouts per project.
• Works with conventional and high-velocity duct systems.

Comprehensive reporting Clear documentation.

• Color reports that can be printed, previewed, and saved.
• English and metric unit support for inputs and outputs.

Benefits

Code-aligned residential duct design Design to ACCA Manual D.

• Reduces sizing errors with standardized procedures.
• Integrates fitting losses and return-side effects for realistic results.

Faster, clearer documentation Streamlined deliverables.

• Color reports simplify submittals and installer communication.
• Multiple sizing methods match office standards or manufacturer schedules.