#3162 CBECC-Com 2019: Occupied Standby Mode

[Nikhil Kapur]

User - Question about Occupied Standby Mode as laid out by Section 120.2(e)3: When a zone system (FCU, WSHP) shuts down after unoccupancy for 5 min, if a de-coupled DOAS is providing OSA directly to the zone, does there have to be a damper that shuts off that flow as well? Or can the DOAS continue to supply a constant flow of the design OSA? This assumes a zone with a design OSA of 0.15 CFM/sf where DCV is not required.

[John Arent]

I interpret the Title 24 code as requiring shutoff ventilation controls with DOAS systems, but I would prefer to confirm this interpretation with the CEC.

[Nikhil Kapur]

1/21/2020 CEC - The requirements target space conditioning and ventilation. And in ‘D’ below, it says to shut off ALL airflow.