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Re: [EnergyPlus_Support] Annual Peak cooling variable ?

Dr. Li, 
Either you have not looked at this model, or need to learn how the surface adjacency of Energy Plus works- as the floor is "surface" so the boundary conditions are "surface" with the identified surface being the name of the same surface.  The South, North and East walls are internal- as is the floor. The external adjacent to exterior are roof/ceiling and west wall. The model shows a 16% cooling load reduction, and 35% cooling energy consumption I think that is rather good.  The dollar per kW numbers for cooling system size are just to fill blanks, and change for each building.  I have just one more question for you-  The most typical PCM applications are inside of insulation, as shown in the model I sent-- how do you imagine might be a better application of PCM such as attached image than between insulation and drywall as configured in this model?


Jeremiah D. Crossett  | Senior Analyst  |  Phase Change Energy Solutions
120 E. Pritchard St.  | Asheboro, NC 27203  | Mobile 503-688-8951


On Thu, Sep 20, 2012 at 5:26 AM, YuanLu Li <yli006@xxxxxxxxxxx> wrote:

Hi, Jeremiah
I do not think that I need to continue with this topic with you.

"First I must mention that the adjacency of the surfaces with PCM are external-"

There is no wall or ceiling  in your building that is internal.  Floor is also to ground. The PCM layer is insulated from the exterior, as is in the inner layer next to the dry wall.  Is this the best way to add the PCM?


I know what is EPlus, and how .rvi etc are to be used.  I know what is in the SQL script.  All the data in the ESO are in there.


I do not run simulation like you do and am not interested in the common .csv, unless it has some meaningful results.

I have a generic value of $2000 per Ton for chiller provided to me by a user and research, for projects the number changes - what is useful is to be able to use a number, as I have no problem getting the bid price for actual systems or using generic figures for generic models.
I already mentioned that.  Call a tender to get all you want.  Why bother to add it to the simulation which is mainly for the building and not for the equipment.  Eplus is not designed for material research, either.  But it is a good tool to provide a controlled environment to test the material when used as a building material.  May be you do not know how to this.  I am not willing to discuss with you on this topic.
The generric cost  number does not mean anything.  It varies from place to place and does not hold for the different configuration of the same equipment type.  .  The number you quoted in you example for the DX coil is well to high.  $5,700 for a 1000w coil.  $5.7 for 1kW is too low.
If yu think they should be included, go ahead.  I do not care about the cost output in the EPlus, as they do not apply to my county.

Go ahead and do what you want and ask what you want.  You are the bioPCM expert, and I do not think I would use the biostix your way. 
In fact, I am not really interested in HVAC system  for general use.  Only special buildings with special  application requirement would need customed HVAC.  Comfort is not one of the requirements.
 Dr. Li  

Date: Wed, 19 Sep 2012 19:16:40 -0700

Subject: Re: [EnergyPlus_Support] Annual Peak cooling variable ?

Dr. Li, 
This is fun- you make me really work to make my point-thanks---  I guess I should have mentioned that I am useing jE+ as it provides the ability to populate values from E+ variables- (more on this below)
  • My bullet point comment on your other comments-
Ice has the heat  storage and release effect at 0°C. 
  • This exzample model uses BioPCM with a melting temp or Q value of 27c for the roof and 25c for the external wall.
 Because the values are already in the ..zSz.csv file, which is smaller and easier to extract.  So, why making the live more difficult. If you have the parametric file name set up in a list, a loop can open the  zSz.csv, go to the last line - 2 and pick out the values, and append them to a new file in the format of your choice. The peak values are automatically generated in the sizing file and no .RVI file is needed.  The normal .csv file would only accept a single value data for each column.  Therefore, the peak value cannot be sent there.  You can ask the developer to change the averaged value to peak, then will also show automaatically in a annual listing.  May be be both as two single field data.

6.1.3 RVI/MVI file ? in the EnergyPlus package, a utility (ReadVarsESO, see E+ InputOutputReference) for extracting variable and meter values from the E+ output files (?eplusout.eso? and ?eplusout.mtr?) is provided. It will produce a more usable data table in CSV format. To use this utility, you need to specify a RVI or MVI file, which defines the source and variables to be extracted with ReadVarsESO. See 6.1.3 for more particulars of this file. 7.6 Result and Report Tables EnergyPlus simulations can generate large amount of output. Rarely all of these information are required for (especially) a parametric study. A good practice is to define as few output as possible in the EnergyPlus models, and to extract exactly the information required for further analysis. jEPlus will collect CSV tables from each job directory, and compile a single table containing all results from the batch. The summary data table is named ?SimResults.csv? and is stored in the Work directory. Also stored are ?RunTimes.csv? and ?SimJobIndex.csv?, which contain EnergyPlus simulation error count and CPU time, and the corresponding index table of the jobs. Full Job Index files can be generated using the ?Create Job Indexes? command on ?Tools? menu. A number CSV files will be generated, along with a SQL script that creates all tables in the job index database.

You would need a common .csv file for the 100 plus run.  The .csv in one simulation will not show all the values.  The data you need are in two places, .ESO  and   ..zsz.csv automatically without making a output request. Even if you have the value in the main .csv file, you will still need to collect them from 1000 plus .csv files.
  • See attached example of a common csv file from a 100 plus run. jE+ does this automaticly as well as has provides Min/Max post processing. Again the problem is when Energy Plus outputs Sensible Cooling Rate as an annual average it does not 

Component cost is never an element in the EPlus simulation input.  Even in an manufacturing factory floor, it is not possible to get the component cost.  You can try contacting Carrier, Hitachi, or GE and find out whether they can provide you with the DX coil cost, even if it is a replacement  part for a current unit.
  • I have a generic value of $2000 per Ton for chiller provided to me by a user and research, for projects the number changes - what is useful is to be able to use a number, as I have no problem getting the bid price for actual systems or using generic figures for generic models.
  • The ability to model costs is currently in E+.. See Energy Plus documentation component cost line item InputOutputRefrence page 1775, and the idf I provided as an example-- the need would be to have this output as a variable rather then just to HTML, and if possible to be able to report a value per calculated heating or cooling load (possibly this was not included back when you read all the manuals) ComponentCost:LineItem Each instance of this object creates a cost line item and will contribute to the total for a cost estimate. Each line item is reported in table form in the tabular report file. The user must request that this report be generated by including a Output:Table:SummaryReports object with the Component Cost Economics Summary option selected. The style of a tabular report can be controlled using the OutputControl:Table:Style object. Cost estimates are not currently general in that they cannot be performed for every type of component that could be included in an EnergyPlus model. Although a ?General? option is available where all information needed for the cost line item is input by the user, the usefulness of cost modeling within EnergyPlus is expected to be enhanced when quantities are obtained from elsewhere in the input file or computed during a simulation. The cost computations are programmed in selected ways for selected objects. The objects available and the type of cost modeling that may be performed are discussed in detail in the discussion of Reference Object Type field. A particular instance of this object will always have many blank fields. Entering values in too many fields may cause an error because the program may determine how a particular cost is to be calculated based on the presence of non-zero values in particular fields. The input object includes fields that are reserved for future use in expanded cost estimate and investment analyses planned for future versions of EnergyPlus. If you would like to request additional objects or different methods of modeling component costs, feel free to describe your needs and submit a request via email to energyplussupport@gard.com.
All the cost in the EPlus are fuel and electricity cost calculated from the demand, and adjusted for efficiency performance, schedules (Season,Off peak, etc.), different locations, etc.  They are there mainly for LEED certification.  They have nothing to do energy conservation design.
  • These are something I have been meaning to use in tandom with component cost line item for ROI projections  thanks for the reminder. 

Jeremiah D. Crossett  | Senior Analyst  |  Phase Change Energy Solutions
120 E. Pritchard St.  | Asheboro, NC 27203  | Mobile 503-688-8951




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