Example issue

[berserker335]

Hi,

Thanks a lot for your code, it helps me to understand how energyplus API works.

I was trying to simulate the Amphitheater example and I got this issue with the energyplus simulation (I downloaded directly the .idf and the .epw files from github and made this simulation thanks to EP-Launch) :

I got this error file :

Program Version,EnergyPlus, Version 24.2.0-94a887817b, YMD=2025.07.16 18:13,
************* Beginning Zone Sizing Calculations
** Warning ** Weather file location will be used rather than entered (IDF) Location object.
** ~~~ ** ..Location object=MILIANA
** ~~~ ** ..Weather File Location=Luxembourg AP LU LUX ISD-TMYx WMO#=065900
** ~~~ ** ..due to location differences, Latitude difference=[13.32] degrees, Longitude difference=[3.98] degrees.
** ~~~ ** ..Time Zone difference=[1.0] hour(s), Elevation difference=[47.41] percent, [339.00] meters.
** Warning ** ProcessScheduleInput: Schedule:Constant="ALWAYS ON DISCRETE", Blank Schedule Type Limits Name input -- will not be validated.
** Warning ** ProcessScheduleInput: Schedule:Constant="ALWAYS ON DISCRETE 3", Blank Schedule Type Limits Name input -- will not be validated.
** Warning ** ProcessScheduleInput: Schedule:Constant="ALWAYS OFF DISCRETE", Blank Schedule Type Limits Name input -- will not be validated.
** Warning ** ProcessScheduleInput: Schedule:Constant="ALWAYS ON CONTINUOUS", Blank Schedule Type Limits Name input -- will not be validated.
** Warning ** ProcessScheduleInput: Schedule:Constant="ALWAYS ON DISCRETE 4", Blank Schedule Type Limits Name input -- will not be validated.
** Warning ** ProcessScheduleInput: Schedule:Constant="ALWAYS ON DISCRETE 5", Blank Schedule Type Limits Name input -- will not be validated.
** Warning ** ProcessScheduleInput: Schedule:Constant="ALWAYS ON DISCRETE 6", Blank Schedule Type Limits Name input -- will not be validated.
** Warning ** GetHTSurfaceData: Surfaces with interface to Ground found but no "Ground Temperatures" were input.
** ~~~ ** Found first in surface=SURFACE 6
** ~~~ ** Defaults, constant throughout the year of (18.0) will be used.
** Warning ** CheckUsedConstructions: There are 25 nominally unused constructions in input.
** ~~~ ** For explicit details on each unused construction, use Output:Diagnostics,DisplayExtraWarnings;
** Warning ** GetSimpleAirModelInputs: ZoneInfiltration:DesignFlowRate="TZ_AMPHITHEATER 189.1-2009 - SECSCHL - AUDITORIUM - CZ4-8 INFILTRATION 77.0 PERCENT REDUCTION", Design Flow Rate Calculation Method specifies Flow Rate per Exterior Surface Area, but Exterior Surface Area = 0. 0 Infiltration will result.
** Severe ** UpdateZoneSizing: Cooling supply air temperature (calculated) within 2C of zone temperature
** ~~~ ** ...check zone thermostat set point and design supply air temperatures
** ~~~ ** ...zone name = TZ_AMPHITHEATER
** ~~~ ** ...design sensible cooling load = 628045.18 W
** ~~~ ** ...thermostat set point temp = 0.000 C
** ~~~ ** ...zone temperature = 14.121 C
** ~~~ ** ...supply air temperature = 14.000 C
** ~~~ ** ...temperature difference = -0.12055 C
** ~~~ ** ...calculated volume flow rate = 1853308.02114 m3/s
** ~~~ ** ...calculated mass flow rate = 2134236.19052 kg/s
************* Beginning System Sizing Calculations
************* Beginning Plant Sizing Calculations
** Warning ** GetOAControllerInputs: Controller:MechanicalVentilation="CONTROLLER MECHANICAL VENTILATION 1"
** ~~~ ** Cannot locate a matching DesignSpecification:ZoneAirDistribution object for Zone="TZ_AMPHITHEATER".
** ~~~ ** Using default zone air distribution effectiveness of 1.0 for heating and cooling.
************* Testing Individual Branch Integrity
************* All Branches passed integrity testing
************* Testing Individual Supply Air Path Integrity
************* All Supply Air Paths passed integrity testing
************* Testing Individual Return Air Path Integrity
************* All Return Air Paths passed integrity testing
************* No node connection errors were found.
************* Beginning Simulation
** Warning ** CalcOAController: Minimum OA fraction > Mechanical Ventilation Controller request for Controller:OutdoorAir=CONTROLLER OUTDOOR AIR 1, Min OA fraction is used.
** ~~~ ** This may be overriding desired ventilation controls. Check inputs for Minimum Outdoor Air Flow Rate, Minimum Outdoor Air Schedule Name and Controller:MechanicalVentilation
** ~~~ ** Minimum OA fraction = 1.0000, Mech Vent OA fraction = 0.5091
** ~~~ ** Environment=2020, at Simulation time=01/01 09:00 - 09:15
** Warning ** Missing 'Temperature Setpoint' for node named named 'NODE 3'.
** Fatal ** checkSetpointNodesAtEnd: At least one node does not have a setpoint attached, neither via a SetpointManager, EMS:Actuator, or API
...Summary of Errors that led to program termination:
..... Reference severe error count=1
..... Last severe error=UpdateZoneSizing: Cooling supply air temperature (calculated) within 2C of zone temperature

---

************* ===== Recurring Error Summary =====
************* The following recurring error messages occurred.

---

************* ** Warning ** Controller:OutdoorAir="CONTROLLER OUTDOOR AIR 1": Min OA fraction > Mechanical ventilation OA fraction, continues...
************* ** ~~~ ** This error occurred 38540 total times;
************* ** ~~~ ** during Warmup 0 times;
************* ** ~~~ ** during Sizing 0 times.
************* ** ~~~ ** Max=1.000000 Min=1.000000

---

---

************* ===== Final Error Summary =====
************* The following error categories occurred. Consider correcting or noting.
************* Nominally Unused Constructions
************* ..The nominally unused constructions warning is provided to alert you to potential conditions that can cause
************* ..extra time during simulation. Each construction is calculated by the algorithm indicated in the HeatBalanceAlgorithm
************* ..object. You may remove the constructions indicated (when you use the DisplayExtraWarnings option).

---

************* EnergyPlus Warmup Error Summary. During Warmup: 0 Warning; 0 Severe Errors.
************* EnergyPlus Sizing Error Summary. During Sizing: 11 Warning; 1 Severe Errors.
************* EnergyPlus Terminated--Fatal Error Detected. 38554 Warning; 1 Severe Errors; Elapsed Time=00hr 00min 8.36sec

---

Did you use this file for your simulation with the energyplus API for python ?

I also tried to simulate the example but I got this error :

399 # check for simulation errors
400 if self.energyplus_runner.failed():

--> 401 raise RuntimeError(f"EnergyPlus failed with {self.energyplus_runner.sim_results['exit_code']}")
403 # simulation_complete is likely to happen after last env step()
404 # is called, hence leading to waiting on queue for a timeout
405 if self.energyplus_runner.simulation_complete:

RuntimeError: EnergyPlus failed with 1

---

I believe that the first part of my question is the main source.

[antoine-galataud]

Hi @berserker335, thanks for your question.

If you try to use the provided .idf example as is with energyplus, it is expected to fail as there is no default setpoint manager (SPM) associated with the supply air temperature node (NODE 3). The SPM is actually "replaced" by the agent which decides the next setpoint value on each timestep.
So if you want to run the .idf in a "standalone" manner, you'll have to modify it first (e.g. add a SPM OutdoorAirReset that will reset the setpoint according to outdoor air temperature).

Hope it helps!