What I am trying to do is :
I want the RTU / VAV system to see a different outdoor air temperature at the OA inlet, such that: Tinlet = OA + deltaT
The idea is to modify the actual outdoor air temperature entering the RTU / OA mixer (for example, to represent a rooftop microclimate effect), without changing the EPW weather file, because I only want the OA stream going into the air loop to be affected. Other calculations like the building envelope or infiltration should remain unchanged.
I tried using EMS,
EnergyManagementSystem:Actuator, VAV1_OAInlet_T_Act, !- Name VAV_1_OAInlet Node, !- Actuated Component Unique Name Outdoor Air System Node, !- Actuated Component Type Drybulb Temperature; !- Actuated Component Control Type
But when I look at the output:variable 'System Node Temperature', I’m seeing that the temperature difference between the OA node and the VAV_5_OAInlet Node is only around 3°C. it fluctuates by about ±3°C instead of staying exactly at +3°C. Why is that happening, and how can I make it apply an exact +3°C offset?
I’ve shared the download link to my IDF file here.
https://drive.google.com/drive/folders/1O9C6lqUWtXWUhII_2dVn5CAKJGZmGI3T?usp=drive_link
Thank you!
