Room Air Distribution
ASHRAE Technical Committee 5.3

The ASHRAE Handbook is published in a series of four volumes, one of which is revised each year, ensuring that no volume is older than four years.

The Handbook can be purchased at the ASHRAE Bookstore by clicking on this link.

This TC is responsible for the following chapters

Fundamentals Volume:  Space Air Diffusion
Room air distribution systems are intended to provide thermal comfort and ventilation for space occupants and processes. Although air terminals (inlets and outlets), terminal units, local ducts, and rooms themselves may affect room air diffusion, this chapter addresses only air terminals and their direct effect on occupant comfort. This chapter is intended to present HVAC designers the fundamental characteristics of air distribution devices. For information on naturally ventilated spaces, see Chapter 16. For a discussion of various air distribution strategies, tools, and guidelines for design and application, see Chapter 57 in the 2011 ASHRAE Handbook—HVAC Applications. Chapter 20 in the 2012 ASHRAE Handbook—HVAC Systems and Equipment provides descriptions of the characteristics of various air terminals (inlets and outlets) and terminal units, as well as selection tools and guidelines.

HVAC Systems & Equipment Volume:  Room Air Distribution
Supply air outlets and diffusing equipment introduce air into a conditioned space to obtain a desired indoor atmospheric environment. Return and exhaust air are removed from a space through return and exhaust inlets (inlet and outlet are defined relative to the duct system and not the room). Various types of air outlets and inlets are available as standard manufactured products. This chapter describes this equipment, details its proper use, and is intended to help HVAC designers select room air distribution equipment applicable to the air distribution methods outlined in Chapter 57 of the 2011 ASHRAE Handbook—HVAC Applications.

HVAC Applications Volume:  Room Air Distribution
Room air distribution systems, like other HVAC systems, are intended to achieve required thermal comfort and ventilation for space occupants and processes. Although air terminals (inlets and outlets), terminal units, local ducts, and the rooms themselves may affect room air distribution, this chapter addresses only air terminals and their effect on occupant comfort. This chapter is intended to help HVAC designers apply air distribution systems to occupied spaces, providing information on characteristics of various air distribution strategies, and tools and guidelines for applications and system design. Naturally ventilated spaces are not addressed; see Chapter 16 of the 2013 ASHRAE Handbook—Fundamentals for details. Also see Chapter 20 of the 2013 ASHRAE Handbook—Fundamentals for more information on space air diffusion; Chapter 20 of the 2012 ASHRAE Handbook—HVAC Systems and Equipment for information on room air distribution equipment; and Chapter 48 of this volume for sound and vibration control guidance.

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Technical committees develop and sponsor technical sessions at the winter and annual conferences. Information about their future technical program is discussed at each TC meeting and at the TC’s Program Subcommittee meeting.

ASHRAE publishes papers and transactions from presentations at its conference events. In addition, ASHRAE records most of the seminar sessions from its conferences on DVD. These DVDs are ideal for use at chapter meetings, in university courses, or company lunch and learns. Products available from the most recent conference may be found here.

Some past programs sponsored by this TC:

Orlando, February 2020, Seminar 43: Ventilation Effectiveness Metrics, Part 1: Humans                                          
Orlando, February 2020, Seminar 47: Effective Control of Active Chilled Beam Systems

Technical Committees are responsible for identifying research topics, proposing research projects, selecting bidders, and monitoring research projects funded by ASHRAE. Information about their specific research program is discussed at each TC meeting and at the TC’s Research Subcommittee meeting.

This TC has worked on the following recent research projects:

1666-RP: Experimental Evaluation of the Thermal and Ventilation Performance of Stratified Air Distribution Systems Coupled with Passive Chilled Beams

1741-TRP: Understanding Fan Coil Components and How They Relate to Energy Consumption and Energy Modeling
Co-sponsored by: TC 4.7, Energy Calculations & TC 7.7, Test & Balance

1819-RP - CO2 Demand Control Ventilation in Multiple Zone VAV Systems with Multiple Recirculation Paths

1882-RTAR - Procedure for Estimating Occupied Space Sound Levels in Application of UFAD

ASHRAE writes standards for the purpose of establishing consensus for: 1) methods of test for use in commerce and 2) performance criteria for use as facilitators with which to guide the industry. ASHRAE publishes the following three types of voluntary consensus standards: Method of Measurement or Test (MOT), Standard Design and Standard Practice. ASHRAE does not write rating standards unless a suitable rating standard will not otherwise be available. ASHRAE is accredited by the American National Standards Institute (ANSI) and follows ANSI's requirements for due process and standards development. Standards may be purchased at the ASHRAE Bookstore.

This TC is cognizant for the following standards:

ANSI/ASHRAE Standard 70: Method of Testing for Rating the Performance of Air Outlets and Air Inlets
ANSI/ASHRAE Standard 79: Methods of Testing for Rating Fan-Coil Conditioners
ANSI/ASHRAE Standard 113: Method of Testing for Room Air Diffusion
ASHRAE Standard 129: Measuring Air-Change Effectiveness
ANSI/ASHRAE Standard 130: Methods of Testing for Rating Ducted Air Terminal Units
ANSI/ASHRAE Standard 200: Methods of Testing Chilled Beams

Include other activities, such as MTG involvement, into this section.

ASHRAE Technical FAQs are provided as a service to ASHRAE members, users of ASHRAE publications, and the general public. While every effort has been made to ensure their accuracy and reliability, they are advisory and provided for informational purposes only, and in many cases represent only one person’s view. They are not intended and should not be relied on as an official statement of ASHRAE. Technical questions not addressed may be submitted to the ASHRAE Technical Services department at tse@ashrae.net.