What is ASHRAE 62.1?
ASHRAE 62.1 is the ASHRAE standard Ventilation and Acceptable Indoor Air Quality for buildings other than low-rise residential. It sets minimum outdoor air rates by space type and occupancy, gives procedures for designing ventilation, and allows demand-controlled ventilation that adjusts outdoor air to actual occupancy.
What it is
ASHRAE 62.1 offers several design paths. The Ventilation Rate Procedure sets outdoor air rates per person and per floor area by space type. The Indoor Air Quality Procedure designs to target contaminant concentrations. The Natural Ventilation Procedure covers naturally ventilated spaces.
Demand-controlled ventilation, often using CO2 sensors or occupancy counts, reduces outdoor air when spaces are lightly used and increases it as they fill. Done well, it saves energy while keeping ventilation adequate. Done poorly, it can under-ventilate. The standard is referenced by many codes and by green building rating systems.
Who it applies to / where it is used
ASHRAE 62.1 is used by mechanical engineers, code officials and owners of offices, schools, hospitals outside critical areas, airports, retail and public buildings. It is updated on a regular cycle, so check which edition your local code adopts.
How it is measured / what evidence it needs
Design compliance is shown by calculations. In operation, the question is whether each zone actually receives the outdoor air the design intended.
- Design outdoor air rates by zone
- Measured outdoor airflow at air handlers
- Zone CO2 trends as an indicator of ventilation per person
- Demand-controlled ventilation sequences and sensor calibration records
How Aqueduct helps
Aqueduct runs demand-controlled ventilation with the energy cost counted and each zone verified back in range.
- Zone CO2, temperature and humidity at 60-second refresh through aQ AirSafe
- Outdoor air damper and fan behavior read from the BMS
- Ventilation adjusted where control is enabled, with owner approval
- Energy effect of each ventilation change tracked through aQ EnergySmart