Dear All,

I’m currently modelling a building that uses DOAs with air-side heat recovery for space ventilation in the Proposed Design. As per ASHRAE 90.1 – 2010, section exception a, spaces served by these systems are not required to have demand control ventilation and as such, I’ll model the Proposed outdoor airflow rate as design.

However, for the Baseline Building’s HVAC systems, none of section’s exceptions apply and some spaces need DCV to be modelled. For these spaces, which outdoor airflow rates should I use when the CO2 is below the setpoint? And above?

Thanks for your attention. I'm looking forward to your reply.