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EMS Heating and Cooling setpoint actuators control Air temperature instead of Operative temperature

asked 2019-09-29 10:27:35 -0500

daniellosg gravatar image

Hi Everyone,

I'm working on a script for heating or cooling setpoint temperatures. I need it to be portable to other models, so i'm trying to make it work with loops. The problem is that, although the temperature control calculation option is set to Operative Temperature, the EMS controls the Air temperature.

The script i'm using is quite simple:

<ForAllOccupiedZones>
EnergyManagementSystem:Actuator,
 <LoopZoneVariableName>_FORSCRIPT_ACST_Schedule,
   <LoopZoneIDFName>,
   Zone Temperature Control,
   Cooling Setpoint;
<LoopNextZone>

<ForAllOccupiedZones>
EnergyManagementSystem:Actuator,
   <LoopZoneVariableName>_FORSCRIPT_AHST_Schedule,
   <LoopZoneIDFName>,
   Zone Temperature Control,
   Heating Setpoint;
<LoopNextZone>

EnergyManagementSystem:ProgramCallingManager,
ApplyAST,
BeginTimestepBeforePredictor,
ApplyAST;

EnergyManagementSystem:Program,
ApplyAST,
<ForAllOccupiedZones>
Set <LoopZoneVariableName>_FORSCRIPT_ACST_Schedule = 26,
Set <LoopZoneVariableName>_FORSCRIPT_AHST_Schedule = 23;
<LoopNextZone>

This is a screenshot of the results, that show that Zone Air Temperature (instead of Operative Temperature) is 26°C. The Cooling setpoint is the blue line, but it's behind the zone air temperature and can not be seen. Does anyone know why is this happening?

image description

Please find attached the IDF, in case you need it: https://drive.google.com/open?id=1K5R...

Thanks in advance.

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1 Answer

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answered 2019-10-19 13:20:12 -0500

The thermostat doesn't actually control operative temperature. Rather, it determines the air temperature required to achieve the desired operative temperature and controls for that. If you actuate the thermostat setpoint schedule instead of the heat/cooling setpoint, it should work as desired.

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Comments

1

Note that issue #7570 references this question.

MJWitte gravatar image MJWitte  ( 2019-10-19 13:21:39 -0500 )edit
1

I previously tried with the schedule actuator and worked. However, in order to work, there should be a schedule with a specific name used in dual setpoints, and therefore the script is not completely portable. So, if this setpoint actuator could be made smarter to control operative temperature, it would be great.

daniellosg gravatar image daniellosg  ( 2019-10-20 00:55:10 -0500 )edit

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Asked: 2019-09-29 10:27:35 -0500

Seen: 331 times

Last updated: Oct 19 '19