Pranav's profile - activity

@Bo_Lin I am using OS 1.10.0. At any rate, I think the software should give me an error if I am not modeling the components correctly, it shouldn't just stop working.

@aparker I edited the question. I included a file showing the issue. Hope that helps.

@adhilton the 2 batch files are identical.

Actually I was able to generate the csv file by running the "eplusout.eso" file with the "RunReadESO.bat" batch file from the EnergyPlusV8-3-0 documentation. My EnergyPlusV8-4-0 probably has an issue.

@adhilton, thank you the response! I tried to do so, but encountered the same error. Hope to find a resolution on the issue.... xEsoView is a program that allows me to save the output variable data in the csv format, but only for one variable at a time, and I need to export 40+ variables.

I want to get the OpenStudio output variable values for 8,760 hours in CSV format. I know a couple of discussions have already taken place on this topic.

Based on the discussions, the best option seemed to be to run the out.idf file in the EnergyPlusPreProcess/ directory created by OS using EP-Launch. when I tried that, EP-Launch ran the simulation (4 min 20 sec) and created a couple of CSV files (outSsz and outZsz), but the "Cooling Tower Fan Cycling Ratio,hourly" variable I wanted did not show up in the files, and the eplusout.csv.

The variable DID show up in the out.eso file. I also got the following error:

C:\EnergyPlusV8-4-0\PostProcess\ReadVarsESO.exe is not a valid Win32 application

I have no idea what the error means. I suspect I am not getting the output variable due to this error.

Hello,

I am trying to change a single speed cooling tower serving WSHPs to a variable speed cooling tower, but every time I make the change in OS, it stops working and I have to close it. No error file is generated, so it is not possible to understand the reason for the issue. I am keeping the design inputs same for the single speed and variable speed with the only change being the fan control. Even if I specify a fluid cooler instead of a cooling tower, the issue persists. Even if I change the type of setpoint manager, or delete one / all setpoint managers, the issue persists.

Here is the picture of the configuration:

The heat exchanger exchanges heat with boilers. That's how the system is designed.

Looks like a similar problem was reported previously. https://unmethours.com/question/580/o.... However, answers to that thread don't help me. OS does not seem to model variable speed as readily as single speed.

Please share your thoughts on this.

Pranav

PS:Since I was not able to model the variable speed control in OS, I tried modeling it in E+. E+ simulated the IDF file, but (prima facie) the electrical energy increased instead decreasing.....so that's one more issue. I will write about this if I don't get any helpful tips on the OS issue above!!

Here is the picture of the issue C:\fakepath\OS-April3-1.png

@MatthewSteen, prima facie, it does not appear that specifying the "Supply Air Fan Operating Mode Schedule Name" will capture the "third power" fan savings of the variable speed control. It's still just an On/Off control. Is that correct?

Hello,

OS does not have an option of variable speed fan control for water to air heat pumps. Therefore, I tried modeling the variable speed control in E+ text based editor, but got the following error.

* Severe * MixedAir: Missing temperature setpoint for economizer controller OAC BAG DUMP * Severe * Node Referenced (by Controller)=NODE 189 * ~~~ * use a Setpoint Manager with Control Variable = "Temperature" to establish a setpoint at the mixed air node."

This error showed up after I specified the follwing schedule for "Supply Air Fan Operating Mode Schedule Name", which is needed for "Fan:VariableVolume". Production Schedule, !- Supply Air Fan Operating Mode Schedule Name

I don't understand what E+ is looking for. How could a setpoint be specified for mixed air? Also, why didn't this error show up when a setpoint controller was not specified in OS? Looks like this is an advanced level of HVAC requirement by E+ after variable speed control and fan operating schedule is specified.

Any feedback on this will be helpful!

Regards, Pranav

@rpg777 I imported the model in Google Sketchup, made changes to daylighting settings, launched OpenStudio through Sketchup, saved the OpenStudio file with a different name and ran it. It ran fine and I saw the changes in the IDF file. Thank you for the suggestion.

@MatthewSteen I edited the question, thank you.

@AmirRoth, @NickC,

I found one more thing. When I add the E+ measure for the utility cost calculation (Tariff Selection Time and Date Dependent with Maximum Demand Charge), the simulation takes a lot more time. See image 1 - only 5 minutes compared to 18 minutes in image 2. It's surprising, but that's what's happening!(/upfiles/14582351213730832.png)

Regards, Pranav

Thank you, Amir.

Hello,

My model consists of a fairly complex WSHP system with boilers and cooling towers. 40+ spaces are served by WSHPs. The model also has daylighting in many spaces. It takes approx. 18 minutes for the simulation to complete. The simulation jumps to "Processed 1 base script and 2 merged scripts" fairly quickly (approx. 62% progress). Then it takes a long time to go to the next step. Most of the time is taken by E+ while sizing systems ("Calculating System sizing") and calculating daylighting factors (I think based on the progress shown in OS). Does that seem reasonable? I am not used to seeing a simulation take so long, so want to share this and get feedback.

The simulation snapshots are saved in the file upload section.C:\fakepath\OS-3.png(/upfiles/14581392437980734.png) C:\fakepath\OS-1.png(/upfiles/1458139202950102.png)

I found one thing. When I add the E+ measure for the utility cost calculation (Tariff Selection Time and Date Dependent with Maximum Demand Charge), the simulation takes a lot more time. See image 1 - only 5 minutes compared to 18 minutes in image 2. It's surprising, but that's what's happening!

Pranav

Matthew,

Thank you.

I downloaded OpenStudio 1.10 and tried implementing a plant control scheme using GUI, but the drop-down menu has no options available. Is there a pre-requisite to adding a control scheme?

Pranav

Hello,

I need to sequence 2 boilers in OpenStudio 1.9.1, i.e. the first boiler will operate all the time and the second boiler will work if the load is greater than the capacity of the first boiler. Based on previous posts, it looks like plant equipment control is currently not possible in OpenStudio GUI. Is that also applicable to OpenStudio 1.10?

Also, is a model done in version 1.9.1 compatible with 1.10?

Regards, Pranav

I am new to Openstudio. I inherited an Openstudio 1.9.1 model and I am trying to figure it out as I need to modify it.

Where are daylighting controls specified in OpenStudio? I can see in the Output file that Continuous/Off control is specified for some spaces, but cannot locate the inputs like the control strategy, the fraction of the zone lighting controlled etc. in the .OSM file. Help on this is appreciated!