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2021-03-15 13:10:12 -0500 marked best answer Coupling MATLAB(or SIMULINK) with EnergyPlus?

If it's possible for you, please share any document (theses, paper, etc) that provides (detailed) information about coupling EnergyPlus and MATLAB. I already know about bctvb main tutorial. I need some more practical, case study and exemplary ones.

2021-02-02 11:16:18 -0500 marked best answer Is it accurate for the large office prototype models to use zone multipliers?

I have a problem with the geometry of the DOE reference building. I loaded the model by OpenStudio measure and in the Geometry tab of OpenStudio, it shows only three floors! I realized that the model multiplies middle zones by 10 to simulate floors between top and basement floor. image description

As long as there is no lighting study, Is it valid to do such a thing? Is it enough that the middle floor's ceiling has an appropriate boundary condition?

2020-12-09 09:12:20 -0500 commented question Pumping system / Plant Convergence issue

@Julien Marrec, Thank you. I tried ramping down the setpoint but that couldn't help. Here is a detailed output variable

2020-12-09 07:37:58 -0500 edited question Pumping system / Plant Convergence issue

Pumping system / Plant Convergence issue The following configuration of cooling loops in energyplus works with just a fe

2020-12-09 07:35:58 -0500 edited question Pumping system / Plant Convergence issue

Pumping system / Plant Convergence issue The following configuration of cooling loops in energyplus works with just a fe

2020-12-08 22:43:03 -0500 edited question Trouble getting variable handle in PythonPlugin

Trouble getting variable handle in PythonPlugin I'm having trouble getting some variable handles using PythonPlugin in e

2020-12-08 20:52:38 -0500 edited question Pumping system / Plant Convergence issue

Pumping system / Plant Convergence issue The following configuration of cooling loops in energyplus works without any wa

2020-12-08 20:40:35 -0500 edited question Pumping system / Plant Convergence issue

Pumping system / Plant Convergence issue The following configuration of cooling loops in energyplus works without any wa

2020-12-08 20:30:59 -0500 edited question Pumping system / Plant Convergence issue

Pumping system / Plant Convergence issue The following configuration of cooling loops in energyplus works without any wa

2020-12-08 18:38:39 -0500 edited question Pumping system / Plant Convergence issue

Pumping system / Plant Convergence issue The following configuration of cooling loops in energyplus works without any wa

2020-12-08 18:38:27 -0500 edited question Pumping system / Plant Convergence issue

Pumping system / Plant Convergence issue The following configuration of cooling loops in energyplus works without any wa

2020-12-08 18:36:47 -0500 asked a question Pumping system / Plant Convergence issue

Pumping system / Plant Convergence issue The following configuration of cooling loops in energyplus worrks without any w

2020-12-08 18:06:57 -0500 edited question Why does my simulation terminates in the middle of simulation (7h month))

Why does my simulation terminates in the middle of simulation (7h month)) Hi everyone, I am having the following error.

2020-12-08 00:35:02 -0500 marked best answer How can I set Heat exchanger fluil-to-fluid supply side outlet temperature?

I using primary and secondary loops to provide cooling in my case. A heatexchanger:fluidtofluid is used to connect these two loops. The problem is that the primary loop, which contains water/glycol as the working fluid, cools the heat-exchanger with a supply temperature of -4. I don't want that heat-exchanger outlet on the supply side of heat-exchanger flow the negative temperature. Because the fluid in the secondary loop is pure water. I'm using an ideal heat exchanger.

The green temperatures are my desired temperatures and the red ones with plenty of error are ones that I get! image description

2020-12-07 23:40:10 -0500 edited question Can anyone tell me why my Openstudio model in SketchUp keeps going white?

Can anyone tell me why my open studio model in SketchUp keeps going white? I never save through SketchUp and only open i

2020-12-07 23:37:49 -0500 answered a question Can anyone tell me why my Openstudio model in SketchUp keeps going white?

I think when you start to work with the openstudio application, you are actually adding some objects that the openstudio

2020-12-07 16:03:36 -0500 answered a question How to change CHP type?

Hi @kimiya, in my opinion, each CHP system should be optimized separately. There would be no point in optimization if yo

2020-12-07 03:26:22 -0500 commented answer Trouble getting variable handle in PythonPlugin

Just to be clear, output:variable reporting frequency doesn't matter for the plugin.

2020-12-06 10:30:42 -0500 marked best answer Trouble getting variable handle in PythonPlugin

I'm having trouble getting some variable handles using PythonPlugin in energyplus. I wonder if all the variables listed in the *.rdd output file are available for the python plugin ...

For example here is what I got in the *.rdd file:

Output:Variable,prm,Plant Supply Side Cooling Demand Rate,hourly; !- HVAC Average []

and here is what I used in my python script to get the handle:

self.sensors["demand rate"] = self.e.get_variable_handle(
              state, "Plant Supply Side Cooling Demand Rate", "prm")

Unfortunately, the API returns -1 value for this variable and some other variables. I can't figure out what's the problem. It seems that all the variables listed in the *.rdd file cannot be handled by PythonPlugin. If I'm right, how can one identify available variables(sensors) for each model? I hope that you can help me with this.

P.S.

self.e = self.api.exchange
2020-12-06 00:59:33 -0500 commented question [bcvtb],inputs and outputs energyplus and systemcommand

You need to read the EMS manual. No one here would not do that for you :) Also, I recommend you to ask you bcvtb related

2020-12-06 00:53:29 -0500 edited question How can I get unmet hours during the simulation?

How can I get unmet hours during the simulation? In order to reduce the computational load during the optimization of my

2020-12-06 00:53:17 -0500 asked a question How can I get unmet hours during the simulation?

How can I get unmet hours during the simulation? In order to reduce the computational load during the optimization of my

2020-12-06 00:29:29 -0500 edited question [bcvtb],inputs and outputs energyplus and systemcommand

[bcvtb],inputs and outputs energyplus and systemcommand Hello I am trying to connect idf to system command (Compiled cpp

2020-12-05 23:11:47 -0500 edited answer How can I create a virtual load to activate supply side of plant?

Here is a solution my friend. After autosizing components in the plant loop that you intend to use your virtual load, re

2020-12-05 23:10:09 -0500 answered a question How can I create a virtual load to activate supply side of plant?

Here is a solution my friend. After autosizing components in the plant loop that you intend to use your virtual load, re

2020-12-05 03:12:27 -0500 commented question How can I create a virtual load to activate supply side of plant?

@Julien Marrec, Where should I use it? I didn't get your point. Actually, I got the idea of the virtual load from a pape

2020-12-04 13:54:59 -0500 marked best answer Inconsistency in curve calculations

I found a problem with the curve input/output in my model. The curve is used for chiller performance (EirFTemp). I have reported the following variables:

Output:Variable,Water Cooled Chiller EItoCoolingOutputRatioFofT,Performance Curve Input Variable 1 Value,timestep; !- HVAC Average []
Output:Variable,Water Cooled Chiller EItoCoolingOutputRatioFofT,Performance Curve Input Variable 2 Value,timestep; !- HVAC Average []
Output:Variable,Water Cooled Chiller EItoCoolingOutputRatioFofT,Performance Curve Output Value,timestep; !- HVAC Average []

(since I'm using Chiller:Electric:EIR object, variable 1 is chiller outlet temperature and variable 2 is chiller's condenser inlet temperature) I need to modify the curve output by EMS, so I decided to use sensor variables (chiller outlet temperature & condenser inlet temperature). As you can see in below, I realized the curve is using input variables much different from sensor variables that I'm receiving from energyplus:

image description

Columns with same color should have a same value (at least with a time lag!). But they are much different specially for the chiller outlet temperature. Why the input 1 of the curve is different from chiller outlet temperature?! Where does it come from?!

Update: I should mention that it happens mostly when the chiller outlet temperature setpoint is negative (e.g. -5).

Update (following my response to Julien): I think I narrowed down the problem. The IceStorage-Series-ChillerUpstream.idf example file works fine because there is no night time load on the secondary side of the loop. I changed the night time setpoint. So chiller should charge (with -5 setpoint) & also provide cooling for the secondary loop (with a 6.7 setpoint). Also, the ice storage outlet has a 6.7 C setpoint all the time. Since there are a two-way common pipe and separate pumpings on the primary and secondary side, having both charging and cooling can't be a problem! Here is files where I compared EnergyPlus example with modified one with nightload.

2020-12-04 13:54:46 -0500 commented answer Inconsistency in curve calculations

Thank you @julien Marrec for your time. I really appreciate it. You are absolutely right about capacity function of temp

2020-12-03 18:44:08 -0500 commented question Ice Storage Controls

Hi @bbrannon4, I hope you're doing well. I wonder if you have any ice-making chiller curve data available. I would reall

2020-12-03 18:44:01 -0500 commented question Ice Storage Controls

Hi @bbrannon4, I hope you're doing well. I wonder if you have any ice-making chiller curve data available. I would reall

2020-12-03 18:38:38 -0500 commented question ice storage in openstudio does not change results

Dear @hj630 , I am working on a similar project with academic goals. Can you share your experience with Ice storage mode

2020-12-03 17:21:41 -0500 commented question Ice Storage Controls

Hi @bbrannon4, I hope you're doing well. I wonder if you have any ice-making chiller curve data available. I would reall

2020-12-03 17:21:23 -0500 commented question Ice Storage Controls

Hi bbrannon4, I hope you're doing well. I wonder if you have any ice-making chiller curve data available. I would really

2020-12-03 16:42:56 -0500 received badge  Associate Editor (source)
2020-12-03 16:42:56 -0500 edited question Inconsistency in curve calculations

Inconsistency in curve calculations I found a problem with the curve input/output in my model. The curve is used for chi

2020-12-03 16:11:29 -0500 edited question Inconsistency in curve calculations

Inconsistency in curve calculations I found a problem with the curve input/output in my model. The curve is used for chi

2020-12-03 16:10:35 -0500 edited question Inconsistency in curve calculations

Inconsistency in curve calculations I found a problem with the curve input/output in my model. The curve is used for chi

2020-12-03 15:17:32 -0500 commented question Inconsistency in curve calculations

@Julien Marrec, IceStorage-Series-ChillerUpstream.idf is kinda similar to my case, but there is one big issue with this

2020-12-03 14:37:40 -0500 commented question Inconsistency in curve calculations

@Julien Marrec, IceStorage-Series-ChillerUpstream.idf is kinda similar to my case, but there is one big issue with this

2020-12-03 12:03:02 -0500 marked best answer Integrated Part Load Value (IPLV) calculated is not at the AHRI test condition!

I'm using the default openstudio curve setting for chillers in DOE reference buildings simulation to cool an ice storage tank. I have to set chiller output temperature to negative values (e.g. -5). The simulation completed successfully but here is a warning that concerns me:

Chiller:Electric:EIR = Chiller:  Integrated Part Load Value (IPLV) calculated is not at the AHRI test condition.

I'm not familiar with IPLV variable and how important it is... This chiller is not specially selected for ice-making applications and that might be a problem. Since I'm studying a non-standard cooling system, Is this warning important or not?

2020-12-03 12:02:59 -0500 commented answer Integrated Part Load Value (IPLV) calculated is not at the AHRI test condition!

Thank you @Julien Marrec, that was really helpful. About extending limits and extrapolating (especially leaving temperat

2020-12-03 01:01:10 -0500 edited question Inconsistency in curve calculations

Inconsistency in curve calculations I found a problem with the curve input/output in my model. The curve is used for chi

2020-12-03 00:59:25 -0500 asked a question Inconsistency in curve calculations

Inconsistency in curve calculations I found a problem with the curve input/output in my model. The curve is used for chi

2020-12-02 13:58:13 -0500 edited question Integrated Part Load Value (IPLV) calculated is not at the AHRI test condition!

Integrated Part Load Value (IPLV) calculated is not at the AHRI test condition! I'm using the default openstudio curve s