Newly published ANSI/ASHRAE Standard 62.1-2013, Ventilation for Acceptable Indoor Air Quality, contains several revisions aimed to help industry professionals better meet its requirements.
“The 2013 version of Standard 62.1 continues the trend of increasing clarity while adding flexibility,” says Roger Hedrick, Standard 62.1 committee chair. “These changes will allow designers and building operators to meet the requirements of the standard and provide adequate ventilation airflow to occupants while reducing excess ventilation and the associated energy consumption.“
The 2013 edition of the standard revises and improves the standard in several ways. A number of changes remove inconsistencies within the standard and improve clarity. Significant updates include:
- Zone Air Distribution Effectiveness is modified to increase the ventilation effectiveness of underfloor air distribution systems that meet certain conditions.
- Requirements for the quality of water used in humidification systems are modified and clarified.
- Building level pressurization requirements are clarified, including an added definition of “exfiltration.”
- A performance alternative to the prescriptive exhaust rates has been included. This approach differs from the Indoor Air Quality Procedure, the existing performance-based method for setting supply ventilation rates, in that monitoring of the concentrations of contaminants of concern is required and provides the basis for control of exhaust flow rates.
- The filtration requirement on air entering wetted cooling coils has been modified to change the MERV rating from 6 to 8. This change will reduce potential for particulate deposition on the coils that could lead to biological or other contamination on the coils.
- Toilet exhaust air that is cleaned to Class 1 may be recirculated.
More information can be found on the ASHRAE website.
