Course Description

Let us begin with the fundamentals. Underfloor Air Distribution, commonly abbreviated UFAD, is an HVAC strategy that supplies conditioned air through a pressurized underfloor plenum directly into floor diffusers located within the occupied zone. Unlike conventional overhead systems that attempt to mix air uniformly throughout the entire room volume - including the upper unoccupied space - UFAD relies on a physical principle called thermal stratification to deliver fresh, conditioned air only where people actually are, which is from the floor to about six feet high. The concept originated in Europe in the 1970s, initially in Germany and Scandinavia, and gained significant traction in North America during the 1990s with the widespread adoption of raised access floors in office buildings. UFAD is particularly well suited for open-plan offices, auditoriums, data centers, and any building requiring frequent reconfiguration of workstations, because moving a diffuser under a raised floor is dramatically simpler and cheaper than relocating overhead ductwork.

What you'll learn in this course?

• Explain the fundamental principles of Underfloor Air Distribution (UFAD) and how it differs from conventional overhead mixing systems.

• Identify the key components of a UFAD system, including underfloor plenum, floor diffusers, and terminal units.

• Describe the thermal stratification phenomenon and its role in energy efficiency and indoor air quality.

• Analyze the advantages and limitations of UFAD compared to traditional VAV overhead systems.

• Apply UFAD design guidelines for floor plenum depth, diffuser layout, and supply air temperature.

• Evaluate the impact of UFAD on building energy use, occupant comfort, and ventilation effectiveness.

• Recognize common construction and integration challenges with structural slabs, raised access floors, and underfloor cabling.

• Specify appropriate diffuser types (swirl, linear, variable) based on room load and occupancy patterns.

• Develop basic control strategies for UFAD, including supply fan tracking, zone reset, and floor-level static pressure.

• Assess real-world UFAD case studies and identify best practices for retrofits and new construction.

Prerequisites

• Basic knowledge of HVAC systems, psychrometrics, heat transfer, airflow, and building-services design

• Familiarity with load calculations, controls, raised-floor systems, and ventilation standards is helpful Wiscademy | HVAC Overview of Underfloor Air Distribution (UFAD) 2