ASHRAE 62.1 ventilation, verified in operation
ASHRAE 62.1 sets minimum ventilation and acceptable indoor air quality for buildings other than homes. Beyond design rates, its Section 8 asks owners to keep ventilating as designed and to verify it. Aqueduct records outdoor airflow, CO2 and humidity per zone, the trend data those checks use.
Who it applies to
Commercial, institutional and multifamily common spaces; dwelling units fall under 62.2. The standard is voluntary until a jurisdiction adopts it, which most US mechanical codes do in some form. The current edition is 62.1-2025.
There is no health-based CO2 limit in 62.1. ASHRAE calls the common 1,000 ppm figure incorrect. CO2 appears instead as a control value for demand-controlled ventilation.
Where measured data is needed
Section and table numbers from 62.1 and its published addenda. Your engineer and the authority having jurisdiction decide compliance.
| Requirement | What it asks for | Data Aqueduct supplies |
|---|---|---|
| Table 6-1, breathing zone rates | A people rate plus an area rate per occupancy, with a maximum CO2 above outdoor air for DCV. | Occupancy and CO2 per zone, compared with the design value. |
| 6.3.1, IAQ Procedure | Design compounds and PM2.5 kept below design limits, confirmed by evaluation. | Continuous PM2.5, TVOC and CO2 per zone. |
| 8.3, system operation | Spaces ventilated as Section 6 requires whenever they are expected to be occupied. | Air handler status and outdoor air damper position against occupancy schedules. |
| Table 8-1 task 11a, annually | Verify outdoor airflows, CO2 sensor calibration dates and the DCV CO2 setting. | Outdoor airflow trends and a sensor register with calibration dates. |
| Table 8-1 task 12a, annually | Indoor humidity kept within the Section 5.12 limits. | Relative humidity per zone, with time above the limit. |
Numbers that matter
Maximum CO2 above outdoor air for DCV in retail sales areas in Table 6-1, alongside 7.5 cfm per person.
Source: ASHRAE 62.1-2025 addendum aInterval for re-measuring outdoor airflow and calibrating sensors in Table 8-1; filters are checked quarterly.
Source: ASHRAE 62.1-2022 addendum hAddendum a to the 2025 edition raised the supermarket area rate from 0.06 to 0.12 cfm per sq ft.
Source: ASHRAERelated standards
sites in 21 countries run on Aqueduct.
and 9 clinics in one of India’s top hospital chains.
US airport running water intelligence on Aqueduct.
of commercial real estate under Aqueduct.
FMCG manufacturing campus.
operations run on Aqueduct.
Related
Common questions
Yes. Table 8-1 notes that verification may use live or trended building automation data. Continuous records of outdoor airflow, CO2 and humidity per zone are that kind of data, and Aqueduct exports them for the period your engineer reviews.
It advises by default, naming the zone and the likely fix. Where control is enabled, with owner approval, Aqueduct can reset outdoor air through the BMS for demand-controlled ventilation, holding each zone at its design rate, and every command is logged.
The Ventilation Rate Procedure sets outdoor air from occupancy and floor area. The IAQ Procedure sets it from target concentrations of contaminants, which then have to be shown to stay below their limits.
On fixed cycles under Table 8-1, from quarterly filter checks to periodic airflow tests and a yearly review of the DCV setting. Aqueduct keeps outdoor airflow and CO2 trends between those visits, so drift shows up in the months a manual test would miss. See CO2 monitoring.
See Aqueduct on your own facility.
Bring a site, a utility bill or a question. We will show you where the loss is.