I'm currently running loads on a small school. For the classrooms and offices, we're going with ductless minisplits with ventilation supplied by a DOAS. The DOAS will condition the OA before putting it in the classrooms, so the load should be negligible.

In the cafeteria, we're using a ducted split system and a separate OA system from the one supplying the classrooms. For the time being, we're not using an ERV to precondition the cafeteria OA.

Since there are so many people in the cafeteria, the ventilation requirement is around 2/3 of the total airflow in the space. Naturally, this adds a substantial load to the area.

One possibility we've considered is using the DOAS to supply some of the air to the cafeteria to reduce part of the load. My question is, is there a way to model this scenario in Trace? Say we were using the DOAS to supply 25% of the required ventilation--we'd need to have 25% of the OA being introduced directly into the space @ 72 deg F (or whatever) and 75% of the OA being introduced into the RA duct, unconditioned.

Thank you!