Residential Duct System Design

Residential duct design really can be “made easy,” using a sequence of logical steps that simplifies the process for creating high performance air distribution systems. Designing these systems is a straight-forward process once the home load calculation has been completed and a decision has been made on the HVAC equipment that is going to be installed.

The current version of ACCA Manual D is the reference standard for this program.

  • The key components of duct performance are examined, along with fan performance and the interactions between fan static and resistance to airflow within the duct system.
  • The duct design elements delivered via the load calculation and equipment selection process are evaluated as to their impact on air distribution system design.
  • Duct layout and classification are explored as they relate to various structural styles and geographic location.
  • Fitting equivalent length, duct effective length, critical air flow path calculations and air terminal device performance characteristics are illustrated.
  • The process for creating a basic duct design reference drawing and allocating fan capacity among the rooms is explained to further simplify the design process.
  • Duct sizing calculators, velocity limitation tables and the Manual D design worksheets are used to ensure the duct sizing process is followed.
  • Participants then design an extended plenum, reducing trunk duct system for a typical residential structure.
  • A high level review of duct balancing and performance testing completes the program.