Nancy is a Autodesk® Revit® add-in designed to simplify and automate one of the most repetitive and error-prone tasks in HVAC design: duct sizing and transitions. By focusing on maintaining airflow consistency, Nancy ensures that your ductwork is not only geometrically accurate but also aligned with engineering principles of ventilation.

At its core, Nancy analyses the airflow of connected ducts and automatically generates transitions between circular and rectangular ducts without compromising performance. For example, when resizing a duct branch, Nancy dynamically calculates the equivalent diameter to maintain the specified airflow, ensuring that changes in shape or size do not create inefficiencies. This minimizes guesswork and reduces the need for manual recalculations that can lead to inconsistencies across a model.

Key features include:

• Airflow Preservation – Nancy automatically calculates equivalent diameters and dimensions to ensure air volume remains constant when converting between round and rectangular ducts.
• Smart Transitions – Generate smooth, precise transitions that adhere to HVAC standards, reducing the risk of errors in fabrication or construction.
• Automation of Repetitive Tasks – Eliminate manual duct adjustments, freeing up engineers and designers to focus on higher-value work.
• Consistency Across Models – Standardized results ensure design clarity and alignment across teams and projects.
• Ease of Use – With an intuitive interface embedded in Revit, Nancy integrates seamlessly into existing workflows without requiring steep learning curves.

Nancy is particularly useful for projects where airflow precision is critical, such as hospitals, laboratories, office buildings, or any large-scale mechanical system. By automating ductulation while preserving design intent, it accelerates project delivery, improves coordination between disciplines, and reduces costly rework during construction.

Whether you are an MEP engineer, BIM coordinator, or designer, Nancy provides a reliable assistant inside Revit that understands the complexities of ductwork and makes them manageable with a single click. It bridges the gap between engineering accuracy and practical modelling, ensuring your duct networks are both efficient and constructible.

In short, Nancy is not just a duct sizing tool—it’s an intelligent partner that helps HVAC designers deliver better, faster, and more reliable models.