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Hourly Cooling Load Profile

asked 2015-11-14 02:07:45 -0500

A Tan gravatar image

updated 2015-11-16 20:42:24 -0500


I have just started learning how to use OS ver 1.9 today.

I need to create a table of hourly cooling load for export to Excel for each thermal zone for the design day. I have tried using several measures like "Add Meter" and "Add Variable". But I am not able to understand how to complete the job (if it at all is possible with these measures).

Would appreciate any help.


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answered 2015-11-16 15:37:12 -0500

updated 2015-11-16 18:16:04 -0500

From the OpenStudio interface, you can access output files from the "Tree" sub-tab of the "Run Simulation" tab. After a successful simulation, you will be able to see the X.mdd and X.rdd files, where "X" is the same name as your OSM file. These files contain the Output Meter and Output Variable objects according to what components are included in your model. For cooling load, there are lots of options depending upon your system set up (central A/C vs zone HVAC) and what kind of cooling load you're interested in (plant / system energy to meet load, cooling coil load provided, zone cooling load demand, etc.). Below is a screen shot from OpenStudio showing where to access these output files.

image description

To use the measures you mention, you want to match the output variable name observed in the RDD file with the inputs of the "Add Variable" measure and the output variable name observed in the MDD file with the inputs of the "Add Meter" measure. For example, in the RDD file you will see the following output variable if your model has an AirLoopHVAC object:

Output:Variable,*,Air System Total Cooling Energy,hourly; !- HVAC Sum [J]

In the "Add Variable" measure, you should enter "Air System Total Cooling Energy" onto the input field for 'Enter Variable Name'.

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Thank you for your help. As guided, I generated some variables taken from the rdd files and displayed them through the "Result Viewer".

There are so many variables. I understand some but not all. Where can I find explanations of each of these variables?

Specifically, I am looking for zonal cooling load, consisting of the sum of envelope heat, internal heat, people, equipment, lights, infiltration and fesh air heat loss.

Also, how do I dump the output to external files, ascii or excel? Result Viewer seems to generate plots.

A Tan gravatar image A Tan  ( 2015-11-16 19:34:18 -0500 )edit

This should be a separate question. But basically open the Input/Output Reference guide. For each object, you have the inputs, and then the outputs. Example for Fan:ConstantVolume

Julien Marrec gravatar image Julien Marrec  ( 2015-11-17 02:43:36 -0500 )edit

In Results Viewer, it may be easier to look at outputs in "Tree View" instead of "Table View". This will organize variables better, in my opinion. Every OpenStudio run in Version 1.9.0 will output the air temperature and relative humidity of each zone, any other output variables need to be added by the user.

Aaron Boranian gravatar image Aaron Boranian  ( 2015-11-17 12:48:23 -0500 )edit

Thanks for the help. Input/output reference is now understood.

I am already using the Tree View. But how do I get the data points for external processing. Looked through all the output files and didn't find the hourly data I need. Any export features somewhere?

A Tan gravatar image A Tan  ( 2015-11-17 21:23:01 -0500 )edit

This is again another question and it's cluttering the comments.

This question has been asked several times on this site. Search for "csv output". (short story: OpenStudio doesn't produce the .csv, so you have to post process the .eso file with ReadVarEso or query the .sql file, or take the out.idf and run it in EP-Launch)

Julien Marrec gravatar image Julien Marrec  ( 2015-11-18 02:27:42 -0500 )edit

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Asked: 2015-11-14 02:07:45 -0500

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Last updated: Nov 16 '15