For the audience:
DOAS = Dedicated Outdoor Air System
More or less an HVAC system that introduces 100% outdoor air into a building, but heats or cools this same air prior to doing so.
Which leaves me a bit puzzled...(and is this a residential setting?)...if the building is using a DOAS, is the HRV primarily to exhaust indoor air? Typically HRVs bring in outdoor air and exhaust indoor air simultaneously, and do so with reduced loss or gain of humidity. With a DOAS, it seems there are now two units bringing in outdoor air....the DOAS and the HRV. Can you explain this arrangement better for us?
Building Physics Rule #1: Hot flows to cold.
Building Physics Rule #2: Higher air pressure moves toward lower air pressure
Building Physics Rule #3: Higher moisture concentration moves toward lower moisture concentration.