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Year in the EnergyPlus results

asked 2018-11-25 10:18:06 -0500

Philip Caesar Ebit's avatar

updated 2018-11-25 10:20:24 -0500

Hi all, I run my building energy model in energyplus. When I see the results in the results viewer I notice that the YEAR on the simulation result is 2002 (see attached image). I would like to ask if is it possible to change to another year, say 2018? If yes, how will I do that? Thank you so much your help is much appreciated. image description

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answered 2018-11-28 11:51:38 -0500

Just to clarify: the EPW file contains weather data, and the contents could come from many different sources. The contents of the EPW could be AMY (Actual Meteorological Year) or TMY (Typical Meteorological Year) or something else altogether (e.g. multiple years of synthetic data).

The connection between the contents of the EPW and the year that EnergyPlus labels results with depends upon a number of different inputs. For version 9.0 and later, the RunPeriod object allows the specification of start and end years. If the "Treat Weather as Actual" field is set to "No", then EnergyPlus will label the simulation with your input years and largely ignore the years in the EPW file. If the "Treat Weather as Actual" field is set to "Yes", then EnergyPlus will require that the start date (month, day, and year) appears in the EPW file (along with a few other things).

Check the I/O Ref section on the RunPeriod object for more details.

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I tried converting my older model to E+ version 9.0 and it appears so many error like in the Fenestration:Detailed of my model. Is there a way that can I make IDF file that will give me directly E+ version 8.9? or Is there any other plug-ins in SketchUp that will directly create IDF version 9.0?

Philip Caesar Ebit's avatar Philip Caesar Ebit  ( 2018-11-29 18:05:43 -0500 )edit

What EnergyPlus version is the original model for? If it is before 8.9 (Fenestration:Detailed errors indicate that your model is probably older) then you're getting hit by some bugs in the transition programs that shipped with 9.0. What I have done is used the transition programs shipped with 8.9 to transition up to version 8.9 and then used the "8.9 to 9.0" program that shipped with 9.0 to do the last transition.

Jason DeGraw's avatar Jason DeGraw  ( 2018-11-29 19:16:38 -0500 )edit

my model is v8.7. I try converting v8.7 to v8,8 then v8.8 to v8.9, but when I try converting v8.9 to v9.0.1 it shows an error and it says " Transition Error: Transition utility not found." How can I solve this problem?

Philip Caesar Ebit's avatar Philip Caesar Ebit  ( 2018-12-01 06:45:48 -0500 )edit

Did you install 8.9 after installing 9.0? I bet it's getting confused about which version is which. When I had to do this, I used the transition utilities directly from the command line.

Jason DeGraw's avatar Jason DeGraw  ( 2018-12-02 20:13:03 -0500 )edit

answered 2018-11-25 16:47:46 -0500

rafael.alonso's avatar

updated 2018-11-25 16:47:59 -0500

If I'm not mistaken, it all depends on your weather data. If you are using EPWs from EnergyPlus or any similar database, they normally use data averaged from the last 10-15 years, depending on the source.

If you are interested on simulating your building for the specific climatic conditions of 2018, in your location, then you should probably look into AMY - Actual Meteorological Year, and get an EPW that represents this 2018 for your location. There is a very useful topic regarding AMY in this forum already.

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Thank you Sir for the advised.

Philip Caesar Ebit's avatar Philip Caesar Ebit  ( 2018-11-28 00:49:13 -0500 )edit

answered 2018-11-27 13:51:35 -0500

To build on the above answer, EPWs are built as a composition of the "most representative" months (for each month) over a multi-year range (perhaps 10-15 as stated above - this varies with whether your files contain TMY2, TMY3,...etc. data), for your location. If you look at the attached screenshot of an EPW containing TMY3 data for Central Park, NY, you can see that the data for January comes from the year 1976 while the data for February comes from the year 1988. What that means is the January of '76 most closely approximates the average January for each of the years considered and likewise for February of '88. Theoretically, your EPW can contain data from as many as 12 different years or as few as 1.

For this reason, the year that is being simulated has no real meaning. OpenStudio will allow you to select a specific "year" to simulate for the sole purpose of having dates associated with a particular day of the week in your results. I find that regardless of year I ask OpenSudio to simulate, the results in ResultsViewer refer to 2002; however the OpenStudio/E-Plus results refer to the year I requested.

If you actually want to find results for 2018, I agree with the advice regarding AMY data.

image description

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Thank you Sir for the info.

Philip Caesar Ebit's avatar Philip Caesar Ebit  ( 2018-11-28 00:49:36 -0500 )edit

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Asked: 2018-11-25 10:18:06 -0500

Seen: 1,131 times

Last updated: Nov 28 '18