On average, we breathe air in and out 12 times a minute. Our bodies inhale the gaseous matter to send oxygen though the alveolar walls within our lungs and into our bloodstream. Unfortunately, the half-liter of air that each breath pulls in contains far more substances than oxygen—contaminants that can pass by the nose, mouth, pharynx, and trachea and spread throughout the bloodstream. The effects of any contaminant can range from irritation of the eyes, nose, and throat to severe, life-threatening damage. The effects can even remain hidden for years.
Regardless of how or when it affects any exposed individual, controlling common pollutants indoors is crucial to reducing the risk of a variety of health concerns. ANSI/ASHRAE 62.1-2019: Ventilation For Acceptable Indoor Air Quality specifies minimum ventilation rates, as well as other measures, to meet this purpose and provide indoor air quality acceptable to human applicants.
ANSI/ASHRAE 62.1-2019 defines acceptable indoor air quality (IAQ) as:
“air in which there are no known contaminants at harmful concentrations, as determined by cognizant authorities, and with which a substantial majority (80% or more) of the people exposed do not express dissatisfaction.”
The ANSI/ASHRAE 62.1-2019 standard is intended for regulatory application to new buildings, additions to existing buildings, and changes to existing buildings. It can also guide the improvement of IAQ in existing buildings.
ANSI/ASHRAE 62.1-2019 covers ventilation and air-cleaning system design, installation, commissioning, and operation and maintenance. Beyond ventilation, the standard possesses information pertinent to certain contaminants and contaminant sources—outdoor air, construction processes, moisture, and biological growth.
It includes three procedures for ventilation design: the IAQ Procedure, the Ventilation Rate Procedure, and the Natural Ventilation Procedure.
As explicitly noted in its scope, ANSI/ASHRAE 62.1-2019 applies to spaces intended for human occupancy within buildings. However, this does not include “those within dwelling units in residential occupancies in which occupants are nontransient.”
For acceptable indoor air quality guidelines in residential buildings, please refer to another American National Standard in this same series: ANSI/ASHRAE 62.2-2019: Ventilation And Acceptable Indoor Air Quality In Residential Buildings.
Changes to ANSI/ASHRAE 62.1-2019
This American National Standard has seen numerous changes over the years, with the 2004 edition being revised in its entirety. The 2019 revision updates ANSI/ASHRAE Standard 62.1-2016. Notable changes to ANSI/ASHRAE 62.1-2019 include:
- The scope has removed commentary and more specifically identifies occupancies previously not covered.
- Informative tables of ventilation rates per unit area are now included for checking existing buildings and the design of new buildings.
- The Ventilation Rate Procedure was modified with a new simplified version for determining EV and a more robust option for determining values of EZ.
- Significant modifications were made to the Natural Ventilation Procedure to provide a more accurate calculation methodology and define the process for designing an engineered system.
- Natural ventilation now includes considering the quality of the outdoor air and interaction of the outdoor air with mechanically cooled spaces.
- Air-cleaning devices that generate ozone are now prohibited.
- Humidity control is now expressed as dew point and not relative humidity.
- The standard now defers to ANSI Z9.5 on ventilation for laboratories handling hazardous materials.
- Patient spaces in the scope of ASHRAE/ASHE Standard 170 are now to follow the guidance of that standard. Furthermore, ancillary spaces previously not classified in ANSI/ASHRAE 62.1 have been added.
For further information, Informative Appendix O of ANSI/ASHRAE 62.1-2019 details all changes from the previous edition of the standard.
ANSI/ASHRAE 62.1-2019: Ventilation For Acceptable Indoor Air Quality is available on the ANSI Webstore.