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How do you write an energyplus measure to add more fields in a custom meter

asked 2021-08-10 21:26:44 -0500

becker1212's avatar

updated 2021-08-11 12:04:21 -0500

Hello I am trying to write an energyplus measure that will add more fields to the end of an already existing custom meter. The custom meters I am looking to add to have a varying number of fields, so the measure will also need to be able to insert the fields at the correct index.

The goal is to write an energyplus measure to take the following object:

Meter:Custom,
  unit 1:ElectricityCooling,              !- Name
  Electricity,                            !- Fuel Type
  res ac cooling coil,                    !- Key Name 1
  Cooling Coil Electric Energy,           !- Output Variable or Meter Name 1
  res ac unitary system,                  !- Key Name 2
  Unitary System Cooling Ancillary Electric Energy, !- Output Variable or Meter Name 2

and add the following fields:

  res ac cooling coil,                    !- Key Name 3
  Cooling Coil Crankcase Heater Electric Energy; !- Output Variable or Meter Name 3

So that the final object will be:

Meter:Custom,
  unit 1:ElectricityCooling,              !- Name
  Electricity,                            !- Fuel Type
  res ac cooling coil,                    !- Key Name 1
  Cooling Coil Electric Energy,           !- Output Variable or Meter Name 1
  res ac unitary system,                  !- Key Name 2
  Unitary System Cooling Ancillary Electric Energy, !- Output Variable or Meter Name 2
  res ac cooling coil,                    !- Key Name 3
  Cooling Coil Crankcase Heater Electric Energy; !- Output Variable or Meter Name 3

My initial thought was that "insertExtensibleGroup" might be helpful but I am unsure how to actually use this.

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answered 2021-08-11 22:50:13 -0500

You would probably be better off using pushExtensibleGroup. Meter:Custom is extensible with 2 fields per extensible group so you would need to do something like:

# find the meter you want to modify in the Idf then:
new_grp = OpenStudio::StringVector.new
new_grp  << "res ac cooling coil"
new_grp  << "Cooling Coil Crankcase Heater Electric Energy"
meter.pushExtensibleGroup(new_grp)
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Hello, thanks for the help. That doesnt seem to be working for me, but I suspect it might be because I'm not grabbing the meter properly. Can you tell me if you see anything wrong with the following lines?

custom_meter = workspace.getObjectByTypeAndName("Meter:Custom".to_IddObjectType,"unit 1:ElectricityCooling" )
new_grp = OpenStudio::StringVector.new
new_grp << "res ac cooling coil"
new_grp << "Cooling Coil Crankcase Heater Electric Energy"
custom_meter.pushExtensibleGroup(new_grp)
becker1212's avatar becker1212  ( 2021-08-17 17:40:06 -0500 )edit

workspace.getObjectByTypeAndName returns an OptionalWorkspaceObject. Optional objects are one of the hardest things to get up to speed with in OpenStudio. You can test if they are empty? and if they are not you can get the value. Calling get on an empty optional will cause a crash.

macumber's avatar macumber  ( 2021-08-21 23:29:42 -0500 )edit

Try this:

custom_meter = workspace.getObjectByTypeAndName("Meter:Custom".to_IddObjectType,"unit 1:ElectricityCooling" )
if not custom_meter.empty?
  custom_meter = custom_meter.get
  new_grp = OpenStudio::StringVector.new
  new_grp << "res ac cooling coil"
  new_grp << "Cooling Coil Crankcase Heater Electric Energy"
  custom_meter.pushExtensibleGroup(new_grp)
end
macumber's avatar macumber  ( 2021-08-21 23:30:38 -0500 )edit

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Asked: 2021-08-10 21:26:44 -0500

Seen: 330 times

Last updated: Aug 11 '21