ダクトサイズ一括選定 Pro

This tool instantly and automatically selects the size and thickness of low-pressure galvanized steel ducts used in the design of HVAC and ventilation systems, based on airflow. It can calculate for multiple systems simultaneously and operates completely offline on-site.

■ For those who:
・Are involved in the design and construction of HVAC/ventilation systems
・Want to quickly determine duct size and thickness
・Want to process multiple systems at once

■ Main Features
・Automatically selects round and square duct sizes simply by inputting airflow
・Automatically determines plate thickness (compliant with the Public Building Construction Standard Specifications, 2025 edition)
・Batch input and calculation of multiple systems (import multiple systems at once via copy and paste)
・Freely set the criteria for unit pressure loss (Pa/m), wind speed, and aspect ratio
・Presents multiple dimension options for square ducts. Other sizes can also be checked manually.
- Operates completely offline (no communication required; data is stored only on the device).
- Save and recall for each project.

■ Calculation Basis
- Duct size: Selected using the standard "equivalent pressure method" in HVAC design, equivalent to the friction loss diagram.
- Square duct: Calculated by converting to the "equivalent diameter" that results in the same pressure loss as a circular duct.
- Plate thickness: Complies with the Standard Specifications for Public Building Construction, Mechanical Equipment Construction (2025 edition).

■ Precautions
- This app assumes galvanized steel ducts for low-pressure, general HVAC applications. Smoke exhaust, high-pressure, kitchen ducts, etc., are not covered.
- This app is a design aid tool. The final decision rests with the designer.