ANSI/ASHRAE Addendum n to ANSI/ASHRAE Standard 62-2001 Ventilation for Acceptable Indoor Air Quality Approved by the ASHRAE Standards Committee on June 28, 2003; by the ASHRAE Board of Directors on July 3, 2003; and by the American National Standards Institute on January 8, 2004. This standard is under continuous maintenance by a Standing Standard Project Committee (SSPC) for which the Standards Committee has established a documented program for regular publication of addenda or revisions, including procedures for timely, documented, consensus action on requests for change to any part of the standard. The change submittal form, instruc- tions, and deadlines may be obtained in electronic form from the ASHRAE web site, http://www.ashrae.org, or in paper form from the Manager of Standards. The latest edition of an ASHRAE Stan- dard and printed copies of a public review draft may be pur- chased from ASHRAE Customer Service, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. E-mail: [email protected]. Fax: 404-321- 5478. Telephone: 404-636-8400 (worldwide), or toll free 1-800-527- 4723 (for orders in U.S. and Canada). ©Copyright 2003 American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. ISSN 1041-2336 ASHRAE Standard Project Committee 62.1 Cognizant TC: TC 4.3, Ventilation Requirements and Infiltration SPLS Liaison: Fredrick H. Kohloss Andrew K. Persily, Chair* Roger L. Hedrick Walter L. Raynaud* David S. Bulter, Sr., Vice-Chair* Thomas P. Houston* Lisa J. Rogers Leon E. Alevantis* Eli P. Howard, III* Robert S. Rushing* Michael Beaton Ralph T. Joeckel Lawrence J. Schoen Lynn G. Bellenger Donald G. Koch* Dennis A. Stanke Hoy R. Bohanon, Jr. * Carl A. Marbery* Jan Sundell* Dale J. Cagwin Bernice A. Mattsson* Terry Lee Sutherland James L. Coggins* John K. McFarland Wayne Thomann Elissa Feldman* Christopher O. Muller* James A. Tshudy Francis J. Fisher, Jr.* Guillermo A. Navas Dilip Y. Vyavaharkar* Francis Michael Gallo John E. Osborn* David R. Warden Scott Douglas Hanson* R. Dean Rasmussen* Michael W. Woodford* *Denotes members of voting status when the document was approved for publication ASHRAE STANDARDS COMMITTEE 2002-2003 Thomas E. Watson, Chair David E. Knebel Van D. Baxter, Vice-Chair Frederick H. Kohloss Charles G. Arnold William J. Landman Dean S. Borges Merle F. McBride Paul W. Cabot Ross D. Montgomery Charles W. Coward, Jr. Cyrus H. Nasseri Brian P. Dougherty Davor Novosel Hakim Elmahdy Dennis A. Stanke Arthur D. Hallstrom Michael H. Tavares Matt R. Hargan Steven T. Taylor Richard D. Hermans David R. Tree Stephen D. Kennedy Terry E. Townsend, CO Maureen Grasso, ExO Claire B. Ramspeck, Manager of Standards SPECIAL NOTE This American National Standard (ANS) is a national voluntary consensus standard developed under the auspices of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Consensus is defined by the American National Standards Institute (ANSI), of which ASHRAE is a member and which has approved this standard as an ANS, as “substantial agreement reached by directly and materially affected interest categories. This signifies the concurrence of more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that an effort be made toward their resolution.” Compliance with this standard is voluntary until and unless a legal jurisdiction makes compliance mandatory through legislation. ASHRAE obtains consensus through participation of its national and international members, associated societies, and public review. ASHRAE Standards are prepared by a Project Committee appointed specifically for the purpose of writing the Standard. The Project Committee Chair and Vice-Chair must be members of ASHRAE; while other committee members may or may not be ASHRAE members, all must be technically qualified in the subject area of the Standard. Every effort is made to balance the concerned interests on all Project Committees. The Manager of Standards of ASHRAE should be contacted for: a. interpretation of the contents of this Standard, b. participation in the next review of the Standard, c. offering constructive criticism for improving the Standard, d. permission to reprint portions of the Standard. DISCLAIMER ASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the public in light of available information and accepted industry practices. However, ASHRAE does not guarantee, certify, or assure the safety or performance of any products, components, or systems tested, installed, or operated in accordance with ASHRAE’s Standards or Guidelines or that any tests conducted under its Standards or Guidelines will be nonhazardous or free from risk. ASHRAE INDUSTRIAL ADVERTISING POLICY ON STANDARDS ASHRAE Standards and Guidelines are established to assist industry and the public by offering a uniform method of testing for rating purposes, by suggesting safe practices in designing and installing equipment, by providing proper definitions of this equipment, and by providing other information that may serve to guide the industry. The creation of ASHRAE Standards and Guidelines is determined by the need for them, and conformance to them is completely voluntary. In referring to this Standard or Guideline and in marking of equipment and in advertising, no claim shall be made, either stated or implied, that the product has been approved by ASHRAE. (This foreword is not part of this standard. It is merely needed. Furthermore, since the standard is now focused on informative and does not contain requirements necessary minimum requirements, the ventilation rate requirements are for conformance to the standard. It has not been pro- based on that focus as opposed to the 1989 standard, which cessed according to the ANSI requirements for a stan- was not. Also, in recognition of the fact that indoor air pollut- dard and may contain material that has not been subject ants are generated by both building occupants (and their to public review or a consensus process.) activities) as well as by the contents of a building, the ventila- tion requirements include both a people component (to dilute Foreword to Addendum 62n contaminants from people and their activities) and an area This addendum revises the Ventilation Rate Procedure component (to dilute contaminants from non-occupant-related currently contained in Section 6.1 of ANSI/ASHRAE Standard sources that are more related to floor area than the number of 62-2001. This revision was developed as part of the effort to people). The ventilation requirements for a particular space convert the entire standard to mandatory, enforceable lan- based on people and on floor area are then added together to guage suitable for adoption into building codes and to reflect determine the total ventilation requirement for a space. While new technical information that has become available since the acknowledging that the “additivity” approach does not apply current Ventilation Rate Procedure was prepared in the mid- to all aspects of indoor air quality, the committee believes that 1980s. additivity is the predominant effect when considering multiple contaminant sources that impact occupant perception with The Ventilation Rate Procedure in Standard 62-2001 is respect to odor and irritation. While important questions essentially identical to the version in the 1989 standard and remain regarding additivity, the majority of research data sup- contains a number of requirements that run counter to the cur- port its use in this context. rent objectives of minimum requirements and mandatory, enforceable language. For example, the current standard spec- The first public review of addendum 62n occurred in 1999 ifies outdoor air requirements in the “breathing zone,” which and produced about 70 unique comments. Of these, about half are very difficult to actually measure and therefore to enforce. called for increased ventilation rates, while a smaller number It also requires one to account for air mixing in ventilated suggested further decreases. About 10% of the comments spaces when determining outdoor air rates but provides no addressed the issue of complexity, and these were evenly split specific calculation approach for doing so. Standard 62 also between complaints about too much complexity and requests requires the use of the so-called “multiple spaces” equation to for more detail. About one-third commented on the additive adjust outdoor air rates for recirculating systems that serve methodology for combining the ventilation requirements more than one room. However, this equation is seldom used by based on the number of people with the requirements based on designers (possibly due to its perceived complexity) and, as floor area, but the committee retained this approach based on presented in the current standard, does not apply to many the principles discussed above and the ability to explicitly common system types. adjust ventilation rates based on occupant density. In response The revision in this addendum addresses these issues to many of the public review comments, a full second public related to the objective of code-intended language in a number draft was developed and issued for comment. In this draft, of ways. It specifies the determination of design ventilation some of the ventilation requirements were increased (most rates that can be easily measured so that compliance can be notably in educational buildings) relative to the first public verified, both by review of the design