I am looking at a VAV air loop driven by chilled water cooling coils and electric heating coils. This is in Climate Zone 2A. I noticed that the relative humidity in almost all my zones increases at night to 80% to 90% and then has a hard time coming back down during the day. As a result (I believe), the OpenStudio Results - Zone Conditions report shows more than 6,000 h in excess of 80% RH, while the temperature setpoints are met just fine (80 oF at night, 75 oF during the day).
So, I thought this might be caused by outdoor air being allowed into the building even at night, and I tried to turn it off by creating an Outdoor Air schedule (FBCCTX Outdoor Air) that is 0 at night and 1 during the day, then assigning it to the air loop's outdoor air component (see images below - "Minimum Outdoor Air Schedule Name"). However, I see no change, and the system outside air flow in the EnergyPlus Results Viewer is still not 0 at night.
Is there another trick to turning off outdoor air at night?
