ACCA Updates Manual D Residential Duct Systems

March 14, 2017

The Air Conditioning Contractors of America Educational Institute (ACCA-EI) Standards Task Team (STT) announces the release of an updated ANSI/ACCA 1 Manual D – 2016 (Residential Duct Systems).
 
The ANSI-recognized national standard for residential HVAC duct design positions contractors to properly design residential ducts for constant volume systems and zoned variable air volume systems, over a full range of duct construction materials.

The revised standard has been divided into two portions: normative and informative. The upfront normative sections contain the minimum requirements for conducting a residential duct system design. The informative sections and appendices that follow contain additional explanation, details, and examples on the normative requirements. The principle changes to Manual D – 2016 from the prior 2014 version are:

  • The addition of four normative sections:
    • N1: Normative Requirements for System Design,
    • N2: Manual D Worksheets (and how to complete same),
    • N3: Normative Tables,
    • N4: Fitting Equivalent Lengths. 
  • The informative sections and appendices that follow contain additional explanation, details, and examples on the normative requirements:
    • Updated and expanded Variable Air Volume (VAV) guidance, with detailed examples,
    • Impacts of excess length, sag and compression in flexible ducts,
    • New equivalent length values for flex duct junction boxes,
    • Additional informative discussion regarding accessing of hand balancing dampers located in runout ducts,
    • Additional discussion on system design impact when bypass dehumidifiers are added to an HVAC system,
    • Other non-substantive revisions within the document for clarification or grammatical/editorial corrections.

Copies of ANSI/ACCA 1 Manual D Residential Duct Systems – Third Edition Version 2.5 - 2016 are available now at www.acca.org/store or by calling 888-290-2220.

 

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ACCA is a non-profit association serving more than 60,000 professionals and 4,000 businesses in the indoor environment and energy services community. Our member firms are the nation's most professional contracting businesses, serving residential and commercial customers in every state. With roots stretching back a century, ACCA was incorporated in its present form nearly 50 years ago. Today, ACCA sets the standards for quality comfort systems, provides leading-edge education for contractors and their employees, and fights for the interests of professional contractors throughout the nation. Learn more about ACCA here.