Is It Possible to Implement RH-Based Cool–Reheat Control for VRF Terminals Using EMS in OpenStudio?
Hello,
Following up on my previous question, I have an additional question regarding VRF cool–reheat modeling in EnergyPlus/OpenStudio.
I would like to modify the control logic using Energy Management System (EMS) in OpenStudio. https://unmethours.com/question/10296...
According to the EnergyPlus Input Output Reference for VRF systems: https://bigladdersoftware.com/epx/doc...
it is stated that, for ZoneHVAC:TerminalUnit:VariableRefrigerantFlow, the air stream entering the zone can pass through a cooling coil, a heating coil, and an optional supplemental heating coil (typically assumed to be electric resistance heating).
Based on this, I have the following questions:
I. Is it possible to modify the internal control logic (using EMS) so that:
when the zone temperature is above a certain threshold, the system operates in cooling-only mode,
when the zone temperature is below a certain threshold and the relative humidity is above a specified limit, the system operates in cooling + supplemental heating mode (i.e., cool-reheat for dehumidification),
and when the zone temperature is below the threshold and the relative humidity is below the limit, the system remains off?
II. If modifying the internal VRF terminal logic directly is difficult or not feasible, is it possible to achieve the same control behavior by:
adding a resistive (electric) heating coil at the AirLoop level, and
applying the same temperature- and humidity-based control logic there (e.g., via EMS)?
III. Alternatively, should this be approached by:
running the simulation in OpenStudio,
exporting or accessing the generated EnergyPlus IDF file, and
directly modifying the IDF (including EMS objects) and re-running the simulation outside of OpenStudio?
Thank you.
+250108) I learned that it is possible to add ZoneHVAC:TerminalUnit:VariableRefrigerantFlow to an AirLoop.
