ASHRAE Standard 62.1-2022 is the latest edition of guidelines for ventilation and acceptable indoor air quality in commercial and institutional buildings. It provides methods for determining ventilation rates and other measures to maintain good indoor air quality

The standard outlines three main procedures for calculating mechanical ventilation rates: the Natural Ventilation Procedure (NVP), the Ventilation Rate Procedure (VRP), and the Indoor Air Quality Procedure (IAQP)

Key updates include changes to the Indoor Air Quality Procedure (IAQP), new requirements for natural ventilation in non-attainment zones, and the removal of non-transient residential units from the scope

The IAQP is a performance-based approach that allows for various methods to achieve contaminant concentration limits, including source control and air cleaning. The VRP is a prescriptive approach using predetermined outdoor air intake rates for different space types

The IAQP can lead to reduced ventilation rates, lower energy consumption, and potentially lower capital costs while maintaining acceptable indoor air quality

The standard now specifies test methods for verifying the efficiency of air cleaning systems, such as ASHRAE Standard 145.2 for gas-phase air cleaning systems

The standard now requires objective IAQ verification post-occupancy and a subjective verification where at least 80% of occupants must be satisfied with the IAQ as measured by a survey

The updates in ASHRAE 62.1-2022 can positively impact LEED certification, particularly in areas related to minimum indoor air quality performance and energy optimization

ASHRAE has released a calculator for mass balance equations used with the revised Indoor Air Quality Procedure, available for purchase

While not mandatory, compliance with ASHRAE 62.1-2022 is highly recommended to ensure good indoor air quality, promote occupant health and comfort, and potentially reduce liability risks

The standard provides specific definitions of acceptable IAQ for various space types, listing 14 design compounds, mixtures, and PM2.5 that must remain below specified limits

ASHRAE typically reviews and updates its standards every three years, with the possibility of addenda and errata issued between major revisions

While ASHRAE 62.1-2022 provides general guidelines, healthcare facilities should primarily refer to ASHRAE Standard 170 for specific ventilation requirements in healthcare settings.

The standard provides tables with minimum ventilation rates for various space types, based on both occupancy and floor area. These rates are typically expressed in cubic feet per minute (cfm) per person and cfm per square foot.

The standard provides guidelines for implementing DCV systems, including CO2-based control strategies and occupancy sensors, to adjust ventilation rates based on actual occupancy.

The standard outlines specific criteria for natural ventilation, including minimum openable areas, location of openings, and control requirements. It also addresses limitations in areas with poor outdoor air quality.

The standard specifies minimum efficiency reporting value (MERV) ratings for air filters based on particle size efficiency. It also provides guidance on filter installation and maintenance.

The standard provides specific ventilation rates for enclosed parking garages, including requirements for CO monitoring and ventilation system activation based on contaminant levels.

While the standard primarily focuses on commercial and institutional buildings, it does provide some guidance for common areas in multi-family residential buildings. For individual dwelling units, ASHRAE Standard 62.2 should be consulted.

The standard provides guidelines for exhaust systems in various space types, including kitchens, bathrooms, and laboratories. It specifies minimum exhaust rates and addresses issues such as makeup air and exhaust location.

The standard includes provisions for protecting HVAC systems during construction and renovation, as well as guidelines for flushing out buildings before occupancy to remove contaminants.

The standard requires documentation of the ventilation system design, including calculations, assumptions, and operational parameters. This documentation is crucial for commissioning, operation, and maintenance of the ventilation system.

The standard provides guidance on assessing outdoor air quality and its impact on ventilation system design. It includes provisions for air cleaning when outdoor air quality does not meet specified criteria.

The standard classifies air into four categories based on contaminant concentration, bioaerosol concentration, and odor intensity. These classifications determine the suitability of air for recirculation or transfer to other spaces.

The standard provides specific guidance for spaces with high occupant density, such as auditoriums and meeting rooms, including provisions for increased ventilation rates and considerations for intermittent occupancy.

The standard outlines requirements for monitoring key indoor air quality parameters, including CO2 levels in some cases. It also provides guidance on maintenance procedures to ensure ongoing compliance with indoor air quality standards.