Gaseous Air Contaminants and Gas Contaminant Removal Equipment
ASHRAE Technical Committee 2.3

Scope of TC 2.3

TC 2.3 is concerned with the nature of trace gaseous contaminants; the measurement of their properties; their effects on living things and materials; the means of removing unwanted gaseous contaminants from gases; and the effectiveness, energy usage, and economy of such purification equipment.

New to TC 2.3?  For more information see the TC 2.3 promotional brochure.


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.

Fundamentals: Chapter 11, Air Contaminants

Air contamination is a concern for ventilation engineers when it causes problems for building occupants. Engineers need to understand the vocabulary used by the air sampling and building air cleaning industry. This chapter focuses on the types and levels of air contaminants that might enter ventilation systems or be found as indoor contaminants. Industrial contaminants are included only for special cases. Because it is not a building air concern, the effects of refrigerants on the atmosphere are not included in this chapter; see Chapter 29 for discussion of this topic.

The ASHRAE HVAC FUNDAMENTALS HANDBOOK may be purchased from the on-line bookstore by clicking on the highlighted text.


HVAC Applications: Chapter 47, Control of Gaseous Indoor Air Contaminants

This chapter covers design procedures for gaseous contaminant air-cleaning systems for occupied spaces only. Procedures discussed are appropriate to address odors and gaseous irritants. Removal of contaminants for the express purpose of protecting building occupants (whether against deliberate attack or industrial accidents) or to protect artifacts (such as in museums) requires application of the same design principles, but applied more rigorously and with great emphasis on having specific design and performance data, providing redundancy, and added engineering safety factors. Design for protection is not a focus of this chapter, although published design guidance is included and referenced; for more detail, see Chapter 59. Aspects of air-cleaning design for museums, libraries, and archives are included in Chapter 23, and removal of gaseous contaminants from industrial processes and stack gases is covered in Chapter 30 of the 2012 ASHRAE Handbook—HVAC Systems and Equipment.

The ASHRAE HVAC APPLICATIONS HANDBOOK may be purchased from the on-line bookstore by clicking on the highlighted text.


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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 and are available under Virtual Conference Access.  Recordings may also be available by DVDs.  Products available from the most recent conference may be found in the Bookstore.


TC 2.3 Sponsored Programs:

2023 Summer Conference Tampa
Seminar 48: Emerging Gas-phase Technologies -- What You Need to Know


2024 Summer Conference Indy
Seminar 19: We’re Not Blowing Smoke: What You Need to Know About Wildfire Smoke
Seminar 44: New ASHRAE Standards 185.3, 145.4, and 185.5 for Air Cleaners – What are They and When to Use Them?
Seminar 48: Current Legislation of Gas Stoves: What Is the Impact and How Should We Proceed? 



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.

Active Research Projects:

RP-1869: Evaluation of Indoor Air Contaminants with respect to Development of a Revised Indoor Air Quality Procedure (IAQP) Design Compound and Design Target Lists for Standard 62.1.

RP-1928: Improving efficiency test methods to measure air cleaner performance against airborne particulate contaminants in a recirculating system


Research Resources:

ASHRAE training presentation: "How to Write a Successful RTAR or Work Statement"


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.


TC 2.3 is Cognizant for the Following Standards and Guidelines:

ANSI/ASHRAE Standard 145.1: Laboratory Test Method for Assessing the Performance of Gas-Phase Air Cleaning Systems: Loose Granular Media

ANSI/ASHRAE Standard 145.2: Laboratory Test Method for Assessing the Performance of Gas-Phase Air Cleaning Systems: Air Cleaning Devices

Standard 145.4P - Proposed Standard authorized June 2022. Method of Test for Assessing the Gas-Phase Performance of Air Cleaning Devices and Systems in a Duct-Chamber Apparatus
Proposed Guideline: GPC 27P: Measurement Procedures for Gaseous Contaminants in Commercial Buildings

Other Activities

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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