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Disabling default Output:Meter in OpenStudio

asked 2024-04-30 04:02:12 -0600

updated 2024-04-30 08:12:49 -0600

Hi everyone,

I'm encountering an issue with OpenStudio 3.7.0 where default Output:Meter are (I suppose) added by default to the model just before simulation starts, despite my attempts to disable them using a custom measure. Specifically, I'm interested in suppressing these meters from appearing in the "timestep" frequency report (Electricity:Facility, NaturalGas:Facility, DistrictCooling:Facility, etc.)

If I'm not wrong, I think this is a default behavior by OpenStudio, but we are working with huge URBANopt models and this kind of timestep outputs are so time and resources consuming when applied to an urban area simulation.

Could someone please advise if there's a method or workaround to achieve this? Any insights or alternative approaches would be greatly appreciated.

Thanks!

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Comments

By timestep frequency are you referring to the zone timestep or the system (HVAC) timestep? Zone timestep can be modified by the user in the Number of Timesteps per Hour input field, but the system timestep cannot.

https://bigladdersoftware.com/epx/doc...

sashadf1's avatar sashadf1  ( 2024-05-02 15:51:57 -0600 )edit

3 Answers

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answered 2024-05-06 10:28:31 -0600

I discovered that, in fact, the OpenStudio workflow gem does by default request timestep output variables. See here.

If you are using an OSW to run your simulations, it looks like you can avoid the timestep outputs by using the skip_energyplus_preprocess option like so. We've been using this option for so long in our residential simulations that I forgot what the default behavior is...

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Comments

Thank you, @shorowit. That explanation makes complete sense.

Since I'm using the URBANopt simulation tool, I'm unable to directly access or modify the .osw files because they are created for each building, and the UBEM simulation starts right away.

Would it be possible to enable the skip_energyplus_preprocess option by default in future OpenStudio releases? This adjustment could simplify workflows like mine.

jordibrunet's avatar jordibrunet  ( 2024-05-08 07:07:32 -0600 )edit

I filed an enhancement request for OpenStudio.

shorowit's avatar shorowit  ( 2024-05-08 09:05:40 -0600 )edit

Thank you very much!

jordibrunet's avatar jordibrunet  ( 2024-05-08 14:54:14 -0600 )edit
0

answered 2024-05-03 11:14:51 -0600

updated 2024-05-03 11:49:38 -0600

It sounds very strange...

I could easily reproduce this in OpenStudio by starting a new file (I have used version OS App 1.7.0 and SDK 3.7.0), drawing a simple box model (one thermal zone), applying the default ASHRAE office space type, construction set, and schedule set (including heating and cooling setpoints), activating ideal loads in the thermal zones tab, and without applying any measure (not even the default reporting measure), launch a whole-year simulation with a 6-timestep configuration.

The following code lines always appear at the end of the IDF file generated in run folder, corresponding to Output:Meter objects not configured by the user (and not present in the original OSM file):

Output:Meter:MeterFileOnly,
  NaturalGas:Facility,                    !- Key Name
  Daily;                                  !- Reporting Frequency
Output:Meter:MeterFileOnly,
  Electricity:Facility,                   !- Key Name
  Timestep;                               !- Reporting Frequency
Output:Meter:MeterFileOnly,
  Electricity:Facility,                   !- Key Name
  Daily;                                  !- Reporting Frequency
Output:Meter,
  Electricity:Facility,                   !- Key Name
  Timestep;                               !- Reporting Frequency
Output:Meter,
  NaturalGas:Facility,                    !- Key Name
  Timestep;                               !- Reporting Frequency
Output:Meter,
  DistrictCooling:Facility,               !- Key Name
  Timestep;                               !- Reporting Frequency
Output:Meter,
  DistrictHeating:Facility,               !- Key Name
  Timestep;                               !- Reporting Frequency

Even more, if I model a DHW system, Air-loop based HVAC system, etc., you can get a lot more Output:Meters, always in timestep reporting frequency.

In this simple box model I get the output in sql and eso files for only the Output:Meter objects corresponding to DistrictCooling:Facility and Electricity:Facility, as DistrictHeating:Facility is not supported in the last versions of EnergyPlus (now it's called DistrictHeatingWater:Facility).

Any idea on how to avoid this?


UPDATE: I could reproduce it identically also with OpenStudio App 1.5.0 (SDK 3.5.1).

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answered 2024-05-03 10:17:01 -0600

nmoore's avatar

This is part of the URBANopt output. From my first look there isn't any simple way to remove those outputs. However, since the simulation is going at whatever timestep you've selected, I don't think removing select columns will significantly impact the simulation time.

If you have, as you say, huge UO models, the number of buildings is driving the simulation time to a much larger degree.

I'll continue investigating with developers.

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Asked: 2024-04-30 04:02:12 -0600

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Last updated: May 08