Part 2 of 3 

This full day webinar focuses on the principles involved in designing residential duct work. A practice session is included where attendees sketch a duct design based on the floor plan from the Manual J/S developed in the first session, ACCA Dry Climate Manual J and S, with Wrightsoft. During this session, Residential Equipment Sizing, (Manual S) is reviewed and duct design concepts such as location of registers, the effect of supplies and returns on each other, along with a discussion and explanation of terms like Coanda effect, terminal velocity, throw, spread and Noise Criteria (NC). ACCA Manual T principles that impact California Code and customer comfort are reviewed. Other terms that are covered and explained; external static pressure, blower static pressure/flow tables, total equivalent length, total effective length and friction rate. The plan and equipment selected in day one will be used as a basis for sketches, showing a sample layout and fitting selection prepared by attendees in a practice session. Part of the exercise requires each attendee to calculate the friction rate and determine duct diameters and velocities based on their sketch. Appendices from ACCA Manual D will be used as the source for determining equivalent lengths of ductwork. Also reviewed and discussed will be register placement and selection. A catalog from a register manufacturer is used as the various design elements of throw, terminal velocity, and spread are explained and demonstrated as part of the design.

Agenda:

• Residential duct design principles
• Air distribution concepts
• Equipment performance and static pressure
• Duct design calculations
• Hands-on practice session
• Register selection and manufacturer data
• Practical application and review

The objective of this course is that at the conclusion, participants will be able to:  

• Understand and apply fundamental residential duct design principles based on ACCA Manual D and their relationship to Manual J/S calculations
• Design effective air distribution systems, including proper placement of supplies and returns, and apply concepts such as Coanda effect, throw, spread, terminal velocity, and Noise Criteria (NC)
• Interpret and apply key duct design parameters including external static pressure, friction rate, total equivalent length, and blower performance data
• Calculate duct sizes, airflow, and velocities using friction rate methods and ACCA Manual D appendices
• Develop and sketch a complete residential duct layout based on a floor plan, including fitting selection and register placement for optimal comfort and code compliance

Continuing Education Credits:

CABEC: 6, NATE: 6