I am struggling to reduce my unmet hours for my LEED baseline building in OpenStudio 2.2. The building is occupied M-F 7:00-17:00. However, when I set my HVAC Operation schedule to follow this, I end up with 500 unmet hours during unoccupied periods. When I set the HVAC Operation schedule to "Always On", I end up with 0 unmet hours.
The proposed building uses a VRV which states that: "The VRV shall enter an unoccupied mode - should the ambient space temperatures request conditioned air, the associated fan coil and condensing unit shall be started, and will operate to meet the unoccupied setpoint. The supply fan should be off during the unoccupied schedule." The proposed model has about 113 unmet hours whether or not the HVAC operation schedule is set to Always On or only on during occupied mode.
What are the correct settings to meet the 90.1 requirements for night cycling of the baseline system? If it is only supposed to be on during occupied periods, and if so, how do I reduce unmet hours?
Further notes on the model: The building is a medium office. I have modeled a Type 5 packaged VAV system. My tolerance is 2 F. The heating and cooling setpoints are 70 and 74 respectively with setbacks of 68 and 75. My design day setpoints are defined as constant 70/74 for heating and cooling. The air loop setpoint manager is of type "warmest" with a minimum of 54 and a maximum of 60. The zone sizing is based on "temperature difference" and that difference is set to 20 F. The unmet hours are for both cooling and heating, with twice as many cooling unmet hours. I am using the ddy file associated with this location that I downloaded from the energyPlus weather website.
