Ductsize is a Windows desktop application for designing air distribution systems. It calculates optimal duct sizes for round, rectangular, and flat-oval ducts, computes pressure losses along trunks and runouts, identifies the critical path, reports available and cumulative static pressure at outlets, and provides sound attenuation analysis by octave band and NC levels. The software outputs detailed system summaries and can print a bill of materials with material and labor costs to support estimating and documentation.

Key Features

Automatic duct sizing across shapes Computes optimal dimensions for multiple duct geometries.

• Sizes round, rectangular, and flat-oval ducts.
• Determines runout and trunk sizes with critical path identification.

Pressure loss and static analysis Quantifies system resistance for design checks.

• Reports maximum static pressure loss route and cumulative losses at outlets.
• Shows available static pressure at critical points for fan selection alignment.

Sound analysis Evaluates acoustic performance of ducts.

• Generates octave-band attenuation and NC comparisons per runout.
• Flags additional attenuation requirements where needed.

Bill of materials and reporting Supports estimating and documentation.

• Prints bill of materials with material and labor components.
• Produces system output summaries for submittals and records.

Benefits

Accurate, standards-aligned duct designs Improves sizing decisions and documentation quality.

• Optimizes dimensions and checks pressure losses to meet design targets.
• Sound analysis helps meet NC criteria without overdesign.

Faster takeoffs and coordination Reduces time spent on schedules and estimates.

• Bill of materials and clear summaries streamline submittals and procurement.
• Critical path visibility focuses balancing and commissioning efforts.