Duct Design Course

Learn HVAC duct design through a practical project-based workflow — from room airflow, diffuser selection, return grille sizing, and duct layout drawing to duct sizing, static pressure calculation, noise control, and air balancing.

60+ Enrolled
3–4 Hrs
English
Beginner Level
25 Lessons
English Subtitle
Self-Paced
Certification
One-time purchase: $109.99
Enroll in Duct Design Course

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Duct Design Is More Than Picking a Duct Size from a Chart

Many HVAC learners know that duct size, airflow, velocity, and static pressure are important, but they still struggle to connect these topics into a complete duct design workflow.

This course helps you understand duct design step by step, from airflow and diffuser selection to duct layout and static pressure calculation.

1

You Can Size a Duct, But Not the Whole System

You know how to use a duct sizing chart, but still feel unsure how to arrange the full duct system with branches, diffusers, return air, fittings, dampers, and fan static pressure.

2

Static Pressure Still Feels Confusing

You hear about static pressure often, but still struggle to see how duct length, fittings, dampers, grilles, diffusers, filters, and equipment losses add up across the system.

3

Diffuser and Grille Selection Is Not Always Clear

You feel unsure how to choose diffuser size, grille size, throw, noise level, quantity, and location.

4

Real Duct Layouts Have Practical Constraints

You may understand the theory, but real projects still have ceiling space limits, beams, access issues, fire dampers, balancing dampers, architectural constraints, and coordination with other services.

Who This Is For

Student

HVAC Design Learners

For learners who want to understand how duct design is done in a structured and practical way.

Engineer

Junior HVAC Engineers

For engineers who need to learn duct sizing, diffuser selection, return air design, duct layout, and static pressure calculation.

Company

Facility and Maintenance Teams

For people who deal with weak airflow, noisy ductwork, poor return air, room pressure issues, and comfort complaints.

Project

Project Engineers and Site Engineers

For project personnel who need to read duct drawings, understand duct routing, coordinate ductwork installation, and discuss design issues with contractors or consultants.

Technician

HVAC Contractors and Technicians

For contractors who want to understand the technical logic behind duct size, grille size, diffuser quantity, balancing dampers, and fan static pressure.

This Course May Not Be for You If…

  • You are completely new to HVAC and do not understand basic air conditioning systems yet.
  • You only need a quick duct size answer without learning the full workflow.
  • You are looking for advanced CFD or specialized cleanroom air distribution design.
  • You want someone to review your actual project instead of learning the design method.

New to HVAC? Start with the HVAC Beginner Course first.
Need project-specific review? View HVAC Engineering Services.

What You Will Learn in This Course

01

Room Airflow Calculation

Learn how to determine supply airflow, return airflow, and room pressure relationship before starting the duct layout.

02

Diffuser Selection

Learn how to read diffuser performance data, understand velocity, NC level, throw, diffuser quantity, and diffuser location.

03

Return Grille Sizing

Learn how to size return grilles using catalogue selection and formula-based methods.

04

Duct Layout Drawing

Learn how to develop a duct layout concept, size ducts using software and charts, and understand fittings such as VCDs, MFDs, and diffuser dampers.

05

Static Pressure Calculation

Learn how to calculate pressure losses for straight ducts, elbows, transitions, tee branches, collars, equipment, and total system pressure.

06

Damper and Air Balancing

Learn which type of damper t use, how to strategically place air control dampers, and design a self-balancing duct layout.

Course Outline

The course is structured around a practical duct design workflow with 27 lessons. It starts with project setup, then moves through airflow, diffuser selection, return grille sizing, duct layout, static pressure calculation, and design countermeasures. 

The course starts with an introduction to the sample project including the architectural layout, floor area and room-by-room usage details to prepare for the core lessons. An excel template will be given to keep track of the design progress.

Lessons:

  • Building Load, Type & Layout

Any duct design starts with knowing how much airflow to deliver. In this section, you’ll learn how to calculate the supply airflow needed for each room. You’ll learn how much outdoor air each room receives and check if it meets the requirement. You’ll learn how to create positive/negative pressure.

Lessons:

  • 1.1 Calculating the Room Supply Airflow
  • 1.2 Verification of Room Outdoor Air Supply
  • 1.3 How to Achieve Positive/Negative Pressure

The key to a good duct design starts with a good diffuser design. In this section, you’ll learn important terminologies that help you select a good diffuser. You’ll learn how to determine the optimal number of diffuser based on the throw distance and noise level. You’ll learn which type of diffuser is best for your applications.

Lessons:

  • 2.1 Determining the Diffuser Quantity
  • 2.2 Understanding Key Terminologies
  • 2.3 Characteristic Length & Throw Distance
  • 2.4 How to Select the Right Type of Diffuser
  • 2.5 Diffuser Neck Size & NC Level

Return grille plays an important part in room air circulation. In this section, you’ll learn about air stratification and the best location to put the return grille. You’ll learn how to size a return grille and how return grilles can help improve the thermal comfort in a room.

Lessons:

  • 3.1 Stratification & Air Mixing
  • 3.2 How to Size Return Grille
  • 3.3 Ducted Return vs Free Return

Before going into duct layout design, it is crucial to understand the fundamentals of pressure loss in duct. In this section, you’ll learn how to calculate pressure loss in a duct system and thus, understand why we size ducts in a certain way, and why certain duct fittings are used.

Lessons:

  • Prelude to Pressure Loss Calculation
  • 4.1 Pressure Loss Calculation Tutorial
  • 4.2 Advanced Pressure Loss Calculation
  • 4.3 How to Size Duct Using Manual Methods
  • 4.4 How to Size Duct Using Software

This is the core section of this course. You’ll learn the initial duct route planning and how to overcome the obstacle when transforming from concept to actual layout. You’ll learn how to size the duct, section by section, on AutoCAD drawing. Along the process, you’ll learn how ducts can be simplified/optimized to reduce cost and improve coordination.

Lessons:

  • 5.1 Initial Duct Layout Planning
  • 5.2 Duct Layout Optimization
  • 5.3 How to Simplify & Reduce Duct Cost
  • 5.4 Step-by-Step Layout Design in AutoCAD

A good duct design performs poorly without taking into consideration the air balance and how to actually achieving the design flow. In this section, you’ll learn how to design the damper system for airflow control. You’ll learn about the concept of design for air balancing so that the intended airflow can be properly balanced and delivered to each and every room.

Lessons:

  • 6.1 Types of Damper & Where to Put Them
  • 6.2 How to Design a Self-Balancing Layout

As the final section of the course, you’ll be invited take a self-assessment test to check how much you have taken away from this course. A certificate of completion will be given to you for record purposes.

Lessons:

  • Course Completion
  • Certificate of Completion

What You Get Inside This Course

25 Self-Paced Lessons

Learn online at your own pace. You can complete one module per day or move faster depending on your schedule.

6 Structured Modules

The course is arranged in a practical design sequence from airflow calculation to diffuser/grille selection, duct layout, damper and balancing.

Submission-Ready Template

A professional, submission-ready excel static pressure calculation sheet is provided for you to download for this course and beyond.

Project-Based Learning

Instead of learning disconnected formulas, you follow a practical duct design sequence where you can replicate and reproduce in your own projects.

Certificate of Completion

Learners receive a certificate upon course completion.

Access to Course Platform

Lessons are delivered online through my course platform.

By the End of This Course, You Should Be Able To…

  • Determine supply airflow and return airflow per room.
  • Understand room pressure difference.
  • Read diffuser performance datasheets.
  • Understand diffuser velocity, NC level, and throw.
  • Decide diffuser quantity and location.
  • Size return grilles by catalogue and formula.
  • Develop a duct layout concept.
  • Size ducts using software and duct sizing charts.
  • Understand VCDs, MFDs, and diffuser dampers.
  • Calculate pressure loss for straight duct, elbows, transitions, tee branches, and total duct system pressure loss.
  • Understand fan ESP mitigation strategies.
  • Compare free return and ducted return arrangements.
  • Understand outdoor air supply considerations.

Preview the Learning Journey

Below shows the raw footage of logging into my course platform, exploring the functions, start a course, watch a video lesson, browse through multiple lessons, visit the community forum, read comments from other learners, and posting a question.

Enroll in Duct Design Course

Choose How You Want to Learn

Buy This Course

$109.99

one-time purchase

Best if you only want to learn duct design and prefer a one-time purchase.

Included:

  • Duct Design Course
  • 25 lessons
  • 6 modules
  • Submission-ready template
  • Certificate of completion
  • Self-paced access
Enroll in Duct Design Course

Join Pro Membership

$20

per month

or

$220

per year

Best for learners who want this course plus selected beginner resources beyond this course.

Included:

  • Duct Design Course
  • Chilled Water System Design Course
  • RTS Cooling Load Calculation Course
  • Psychrometric Analysis Course
  • HVAC Beginner Course
  • Pro resources and references
  • Exclusive Pro Zone community
View Membership

Should You Buy the Course or Join the Membership?

Choose this

Best if

Buy HVAC Beginner Course

You only want this course and prefer a one-time purchase.

Join Pro Membership

You want multiple HVAC design courses, technical resources, community access, and continuous learning.

Start with HVAC Beginner Course

You are new to HVAC and need stronger fundamentals first.

Recommendation: If you only want duct design, buy the course. If you want to build a broader HVAC design foundation, Pro Membership is the better learning path because duct design connects closely with cooling load, psychrometrics, chilled water systems, equipment selection, and practical project work.

How Duct Design Fits Into HVAC Design

Duct design sits between cooling load calculation, equipment selection, air distribution, fan selection, ceiling coordination, and site installation.

A duct system that looks acceptable on paper can still create problems if airflow, velocity, pressure loss, diffuser throw, return air path, dampers, and fan ESP are not considered together.

This course focuses on the air distribution side of HVAC design so you can better understand how ductwork affects comfort, airflow, noise, and system performance.

Learn from Practical HVAC Field Experience

This course is taught by Yu Chang Zhen, founder of aircondlounge. The teaching approach is based on practical HVAC experience across design, installation, operation, maintenance, commissioning, troubleshooting, and technical content development.

MBOT Professional Technologist

MASHRAE Independent CxS

HRD Corp TTT Certified Trainer

10+ Years HVAC Field Experience

“My goal is to help learners understand HVAC in a practical, structured, and field-relevant way, not just memorize theory.”

Hero Section Real photo of me explaining at site 2

FAQ

This course is better for learners who already understand basic HVAC concepts. If you are completely new to HVAC, start with the HVAC Beginner Course first.

This is a self-paced online course. You can access the lessons online and learn at your own pace.

The course covers room airflow, diffuser selection, return grille sizing, duct layout drawing, duct sizing by software and chart, duct fittings, static pressure calculation, fan ESP mitigation, noise control, free return versus ducted return, and dedicated outdoor air supply.

Yes. The course covers duct sizing by software and by duct sizing chart.

Yes. The course covers diffuser performance datasheets, velocity, NC level, throw, diffuser quantity, and diffuser location.

Yes. The course covers return grille sizing by catalogue selection and by formula.

Yes. The course covers straight duct pressure loss, elbow pressure loss, transition pressure loss, tee branch and collar pressure loss, equipment pressure loss, and total pressure loss.

Yes. A certificate of completion is provided after finishing the course.

Yes. The Duct Design Course should be included in Pro Membership.

Buy the course if you only want duct design. Join Pro Membership if you want duct design plus other HVAC design courses and technical resources.

Continue Your HVAC Learning Path

After completing this course, you can choose one of the following paths based on your needs to pursue further learning.

Browse All HVAC Resources

Psychrometric Analysis Course

Understand air properties, humidity, sensible heat, latent heat, and HVAC air-side processes.

RTS Cooling Load Calculation Course

Learn how cooling load is calculated and how load affects equipment sizing and airflow requirement.

Chilled Water System Design Course

Learn how chilled water systems, chillers, pumps, cooling towers, flow rate, and system configuration connect to commercial HVAC design.

HVAC Beginner Course

Start here if you need stronger HVAC fundamentals before going deeper into duct design.

Start Learning Practical Duct Design

If you want to understand room airflow, diffuser selection, return grille sizing, duct layout, duct sizing, static pressure calculation, and practical duct design countermeasures, this course gives you a structured path to learn the duct design workflow step by step.

Enroll in Duct Design Course

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