Welcome to the Homepage of SSPC 62.1!

This project committee is responsible for maintaining ASHRAE Standard 62.1,
Ventilation for Acceptable Indoor Air Quality

ANSI/ASHRAE Standard 62.1-2007 is the latest edition of Standard 62. The 2007 edition combines Standard 62.1-2004 and the eight approved and published addenda to the 2004 edition, thereby providing an easy-to-use consolidated standard. Specific information on the contents of each addendum and approval dates for each addendum are included in informative Appendix I at the end of this standard.

First published in 1973, Standard 62.1 is now updated on a regular basis using ASHRAE's continuous maintenance procedures. According to these procedures, Standard 62.1 is continuously revised by addenda that are publicly reviewed, approved by ASHRAE and ANSI, and published in a Supplement approximately 18 months after each new edition of the standard, or in a new, complete edition of the standard, published every three years.

Standard 62.1 has undergone some key changes over the years, reflecting the ever-expanding body of knowledge, experience and research related to ventilation and air quality. While the purpose of the standard has remained consistent—to specify minimum ventilation rates and other measures intended to provide indoor air quality that is acceptable to human occupants and that minimizes adverse health effects—the means of achieving this goal have evolved. In its first edition the standard adopted a prescriptive approach to ventilation by specifying both minimum and recommended outdoor air flow rates to obtain acceptable indoor air quality for a variety of indoor spaces. In its 1981 edition, the standard reduced minimum outdoor airflow rates and introduced an alternative performance-based approach, the Indoor Air Quality (IAQ) Procedure, which allowed for the calculation of the amount of outdoor air necessary to maintain the levels of indoor air contaminants below recommended limits. Today the standard still retains the two procedures for ventilation design, the IAQ Procedure and the Ventilation Rate Procedure. In its 1989 edition, and in response to a growing number of buildings with apparent indoor air quality problems, the standard increased minimum outdoor airflow rates significantly and introduced a requirement for finding outdoor air intake flow requirements for multiple-zone, recirculating systems. The 1999 and 2001 editions made several minor changes and clarifications which did not impact the minimum required outdoor airflow rates. In its 2004 edition – the last time the standard was published in its entirety– the standard modified the IAQ Procedure to improve enforceability, but more significantly, it modified the Ventilation Rate Procedure, changing both the minimum outdoor airflow rates and the procedures for calculating both zone-level and system-level outdoor airflow rates.

The 2007 edition of the standard updates, revises and improves it in several ways, without changing minimum outdoor airflow rates. The standard:

• Clarifies dehumidification analysis requirements in Section 5.10, and offers exceptions to the 65% RH limit requirement and to the net-positive intake-airflow requirement. (Addendum 62.1a)

• Corrects occupant category inconsistencies among Tables 5-2, 6-1 and 6-4, and provides additional information for several occupancy categories. (Addendum 62.1b)

• Updates references and clarifies the text in informative Appendix B, particularly as related to subjective evaluation of air quality. (Addendum 62.1c)

• Updates the information presented in Table 4-1, to be consistent with the U.S. EPA National Ambient Air Quality Standards (NAAQS) as published at the time the addendum was approved, adding PM 2.5 as a criteria pollutant and adding the 8-hour standard for ozone. (Addendum 62.1d)

• Includes a new informative appendix, Appendix I, which summarizes the documentation requirements in the body of the standard thus providing a single point of reference for users. (Addendum 62.1e)

• Updates the purpose and scope of the standard to make them consistent with changes that have already been incorporated into the body of the standard. Specifically, it: excludes single-family houses and multiple-family structures of three or fewer stories from the scope; removes specific minimum outdoor airflow rates for areas that contain smoking or environmental tobacco smoke (ETS); excludes thermal comfort requirements. (Addendum 62.1f)

• Requires proper design for buildings that contain both ETS and ETS-free areas, by requiring (briefly): classification of areas based on expected presence of ETS; pressurization of ETS-free areas; separation of ETS and ETS-free areas; and cautionary signage for ETS-areas. (Addendum 62.1g)

• Adds requirements for residential spaces in buildings with more than three stories to Table 6-1, and deletes Tables E-2 and E-3 from Appendix E, which provided ventilation requirements for residences and vehicles. (Addendum 62.1h)

To view the title, purpose and scope (TPS) of this standard Click Here

ANSI/ASHRAE Standard 62.1 is under continuous maintenance by SSPC 62.1 for which the Standards Committee has established a documented program for regular publication of addenda or revisions.