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2018-05-15 12:23:20 -0600 asked a question Free-cooling on packaged DX AHUs

Free-cooling on packaged DX AHUs Hi, I'm trying to make a water-cooled DX, VAV AHU with the option of a “free-cooling”

2018-04-26 07:53:02 -0600 received badge  Teacher (source)
2018-04-25 14:18:33 -0600 edited answer Openstudio/energyplus precision cooling

Thank you for the great explanation. I used the same method to create a free cooling coil coupled with water cooled DX s

2018-04-25 14:18:09 -0600 answered a question Openstudio/energyplus precision cooling

Thank you for the great explanation. I used the same method to create a free cooling coil coupled with water cooled DX s

2017-11-01 14:40:38 -0600 marked best answer Export to idf file Fails

I've downloaded the OpenStudio 2.3 with EnergyPlus 8.8 and SketchUp 2017. I created a model and when I want to export the idf file from SketchUp OpenStudio plugin, It doesn't let me to do that. I tried to Launch the openstudio first and then export the IDF file. However when I run the OSM model, the simulation fails and I get this error C:\fakepath\123.JPG

"utilities.idf.WorkspaceObject] <2> Attempt to write a disconnected WorkspaceObject out to Idf. [16:13:26.410201 ERROR] Found error in state 'translator' with message ["E:\Git\OS1\openstudiocore\src\utilities\idf\WorkspaceObject.cpp@835 : Attempt to write a disconnected WorkspaceObject out to Idf.::/ruby/2.2.0/gems/openstudio-workflow-1.3.1/lib/openstudio/workflow/util/model.rb:66:in translateModel'\n:/ruby/2.2.0/gems/openstudio-workflow-1.3.1/lib/openstudio/workflow/util/model.rb:66:intranslate_to_energyplus'\n:/ruby/2.2.0/gems/openstudio-workflow-1.3.1/lib/openstudio/workflow/jobs/run_translation.rb:54:in perform'\n:/ruby/2.2.0/gems/openstudio-workflow-1.3.1/lib/openstudio/workflow/run.rb:261:instep'\n:/ruby/2.2.0/gems/openstudio-workflow-1.3.1/lib/openstudio/workflow/run.rb:210:in run'\n:/openstudio_cli.rb:804:inexecute'\n:/openstudio_cli.rb:620:in execute'\n:/openstudio_cli.rb:1517:in<main>'\neval:85:in eval'\neval:85:inrequire_embedded_absolute'\neval:70:in block in require'\neval:64:ineach'\neval:64:in require'\neval:2:in<main>'"]}

Any idea?

2017-11-01 12:49:53 -0600 received badge  Enthusiast
2017-10-30 17:16:04 -0600 asked a question Export to idf file Fails

Export to idf file Fails I've downloaded the OpenStudio 2.3 with EnergyPlus 8.8 and SketchUp 2017. I created a model and

2017-05-01 08:48:16 -0600 commented answer Approximating DOAS to AHUs in EnergyPlus

@MatthewSteen, Thanks for guiding me here. I am also trying to make this configuration in IES. However, I have a lot of

2017-04-30 20:14:19 -0600 received badge  Editor (source)
2017-04-30 20:14:19 -0600 edited question Central DOAS for AHUs in a commercial building

Central DOAS for AHUs in a commercial building Hi, How can I make a central DOAS system (OA Ventilation) to provide OA

2017-04-30 19:51:45 -0600 asked a question Central DOAS for AHUs in a commercial building

Central DOAS for AHUs in a commercial building Hi, How can I make a central DOAS system (OA Ventilation) to provide OA

2017-02-15 16:40:10 -0600 asked a question HTML Table in Parametric runs

I am trying to do a parametric run in EnergyPlus. There are about 7 runs. But The HTML Table is only created for the first and last idf file. How can I have HTML table for all of my runs? Is there something that I missed?

2017-01-15 23:30:29 -0600 commented question How to model ETFE material in E+?

Geometry and structural edges are my concerns. and also which E+ object is better to represent the material properties and U-factor? what if I use a three layer cushion? How can I differentiate them from the simple glass in terms of long wave radiation?

2017-01-13 09:56:39 -0600 asked a question How to model ETFE material in E+?

I am trying to model a Ethylene tetrafluoroethylene (ETFE) roof with EnergyPlus. Does anyone have any experience using ETFE material with EnergyPlus? Any kind of hint or starting point would be helpful.

2017-01-05 16:10:02 -0600 asked a question openstudio templates

How can I assign 4 or 5 templates (Hotel, office, residential, and retail) to a single SketchUp/OpenStudio model? I have a building complex (4 boxes) with different applications. How can I model the entire complex into 1 openstudio model?

If it is not possible, should I directly work in E+ file and assign the right template to each box?

2017-01-05 12:33:26 -0600 asked a question SketchUp and Openstudio plugin

I have upgraded to SketchUp 2017 and also downloaded the OpenStudio 1.14.0.

I realized that I don't have access to the OpenStudio Sketchup plugin. How can I fix that? is this a version problem? should I go back to sketchup 2016?

Thanks

2016-09-21 17:35:16 -0600 commented answer How to increase the CHW cooling Energy

I have all the sizing objects and they look fine to me. in Sizing:System I have chosen the CoolingDesignCapacity and is higher than drawings. Then I used the same number for the district cooling and cooling load range. is it correct to do that?

I used drawings data for the coil design but it seems that it does not work fine. real building CHW flow is quite more than the simulation result during weekends (only weekends). also I have the night cycle On. and there is some zones that are more that setback during night and evenings, the fans are getting On but the chilled water flow is zero orlow

2016-09-21 17:27:30 -0600 received badge  Scholar (source)
2016-09-21 10:05:03 -0600 asked a question How to increase the CHW cooling Energy

I have an E+ model with District Cooling and Heating, AHU With reheat coils which are off during summer. I am running the simulation for july and August.

I believe that I did the right hard sizing for coils and everything based on the mechanical drawings. The Chilled water flow rate are reasonable, matches with real building data, However, the cooling energy which considers the delta T (inlet-outlet CHW supply temperature), and CH Water mass flow rate are considerably low. which may be mean that cooling design capacity is not correct. I tried to increase that or change the coil settings but still I have this problem.

I have checked the ChW inlet and Outlet temperature and delta T is low.

How can I fix this? any idea would be helpful! :)

2016-09-19 13:54:26 -0600 commented answer E+ and DataBase synchronization in BCVTB

Thank you for your response.

I have tried that but the E+ outputs are still one time step ahead than the inputs (after discarding the first token). what do you recommend? what about adding a sample delay in input path?

2016-09-19 13:39:45 -0600 received badge  Supporter (source)
2016-09-19 08:55:07 -0600 asked a question E+ and DataBase synchronization in BCVTB

Hello,

I am trying to send 96 tokens to E+ from a database actor (input to E+). But it seems that E+ produces 97 tokens in its output. The first token is initial values. how can I get rid of that initial token? (That extra token unbalances the comparison between input and output of E+)

The number of iterations at SDF director is 97.

Any Idea?

Thank you.

2016-09-16 10:32:55 -0600 commented question How to turn on the AHU during unoccupied hours?

I am a little bit confused here. When I turn off the AHU and fans (by using AvailabilityManager) during weekend and nights, the NightCycle Does not turn On the fans and system, but when I turn the AHU On (the Fans are Off) seems that fans are working. However the fan electricity profile or CHW profile show a constant consumption rate not an On/OFF shape (because of the cycling run time).

2016-09-15 09:31:41 -0600 asked a question How to turn on the AHU during unoccupied hours?

I am trying to model an office building in EnergyPlus in which AHUs and CHW flow are off during unoccupied hours and they only become On only in case the zones temperature are going above 80 F. (in real building the CHW flow goes ON and OFF, sometimes it is zero)

The AvailabilityManager:NightCycle does not work properly. I do not know the reason (Please help if anyone know how to make it run). So I have to turn ON all the AHUs,Fan and every thing during Unoccupied hours. Is there any other way to avoid that? is there any function of controlling (shutting on/off) CHW and AHUs based on the room temperature in E+?

Do I need to use EMS?

Thanks,

2016-06-28 15:40:19 -0600 asked a question How to connect a database to E+ using BCVTB in each timestep

I am trying to receive data from a database (PostgreSQL)( each row in each time step) and send it to Eplus model. I am using SQLStatement in BCVTB to retrieve data. However it brings the entire 8760 row in each time step. Any suggestion how can I get the first row of data in first time step, the second row in the second time step and the same for other rows?image description

The picture shows how data converted from string to Array of doubles but still time step is the main problem.

2015-10-22 18:08:01 -0600 asked a question PsyRhoAirFnPbTdbW: RhoAir (Density of Air) is calculated <= 0

I am trying to model an office building with different type of HVAC systems. some of the zones are serving by 2 HVAC system. I believe that till now the system modeling is fine. But I keep getting this error message that I don't know how to fix. It seems that one of the zones is too cold.

What is the cause for this error?

PsyRhoAirFnPbTdbW: RhoAir (Density of Air) is calculated <= 0 [-5.22382]
pb =[100487.00], tdb=[-340.17], w=[1.0000000E-005].
   **   ~~~   **  Routine=CorrectZoneHumRat, During Warmup, Environment=INCH'ON ANN CLG 1% CONDNS DB=>MWB, at Simulation time=08/21 12:10 - 12:20
2015-10-22 18:06:26 -0600 asked a question PsyRhoAirFnPbTdbW: RhoAir (Density of Air) is calculated <= 0 [-5.22382]

Hello,

I am trying to model an office building with different type of HVAC systems. some of the zones are serving by 2 HVAC system. I believe that till now the system modeling is fine. But I keep getting this error message that I don't know how to fix. It seems that one of the zones is too cold. Would you please help!!

PsyRhoAirFnPbTdbW: RhoAir (Density of Air) is calculated <= 0 [-5.22382] pb =[100487.00], tdb=[-340.17], w=[1.0000000E-005]. * ~~~ * Routine=CorrectZoneHumRat, During Warmup, Environment=INCH'ON ANN CLG 1% CONDNS DB=>MWB, at Simulation time=08/21 12:10 - 12:20

2015-07-12 14:18:43 -0600 received badge  Student (source)
2015-06-17 23:45:53 -0600 asked a question How to convert .skp file to an .osm file?

I have a large size building model in SketchUp (.skp file). I need to convert the model to an .osm file. I don't want to re-draw the model in sketchUp with OpenStudio Plugin. Is there any way to do that? Or the only way is to start from scratch?

Please Help.

Nasim