by Shane Henson — October 28, 2013—ASHRAE, a building technology society serving more than 50,000 members worldwide, recently published the 2013 version of its indoor air quality standard, ANSI/ASHRAE Standard 62.1-2013, Ventilation for Acceptable Indoor Air Quality, to help users better meet its requirements.
The new standard sets minimum ventilation rates and other requirements for commercial and institutional buildings. According to ASHRAE, it combines the 2010 standard and 10 published addenda to that edition, providing an easy-to-use consolidated standard.
The 2013 edition of the standard also revises and improves the standard in several ways, ASHRAE says. A number of changes remove inconsistencies within the standard and improve clarity. Significant changes include:
- Table 6-2, Zone Air Distribution Effectiveness was 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 were modified and clarified.
- Building level pressurization requirements were clarified, including adding a definition of “exfiltration.”
- A performance alternative to the prescriptive exhaust rates was added. 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.
- Some changes to the ventilation rates and space types in Table 6-1 were made. These added refrigerated warehouses and changed the ventilation rate for sports-related spaces to include a per occupant component, which then allows the use of demand controlled ventilation in these spaces.
- The filtration requirement on air entering wetted cooling coils was 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.
