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Modified weatherfile - time resolution

asked 2015-12-02 11:39:12 -0600

gerald gravatar image

updated 2020-01-20 13:39:43 -0600

Hey, I converted a weather file (through elements excel ) - tried 10 different ways, but it still does not work Here the link to the weather file: Maybe someone could help - thank you very much!! I need to finish a paper and the only thing that does not work is to import that measured climate data :/.

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I tried the following: change at 00:00 to the next hour; change 00:00 at the end of the months to the next months, change in the minute filed: 00:000 to 60:00 --> does not work

antifx gravatar image antifx  ( 2015-12-02 12:49:24 -0600 )edit

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answered 2015-12-02 15:26:23 -0600

updated 2015-12-04 05:20:48 -0600

Guided by the error messages when trying to import your weather file into an OpenStudio model, I found that the header information needs to be changed in order to indicate that there are 6 measurements per hour instead of 1 (one), cf. the following image: DATA PERIODS, 1,6,...

image description

Next, the last line needs to be corrected, see below:

image description

Note also that I changed your minutes column entries from 00 to 60, because otherwise the data could have been interpreted as not being ordered correctly. (I did not verify whether EnergyPlus will read these times correctly or whether you need to translate times such as 01:60 to 02:00, etc, including date corrections at midnight, end of month.)

However, your weather file will still not run because there are missing data (February to mid December missing), which I found out by inspecting the err file after a failed simulation run:

image description


  1. all entries have to be strictly chronologically ordered, i.e. no missing lines, no duplicate lines, no blank lines

  2. all hours have to be complete, i.e. in this case with 6 measurements per hour.

  3. OpenStudio does not support more than one data period in a weather file (verified for version 1.8.0), i.e. all the weather data have to be contiguous

  4. Originally, you wanted to run simulations from December to January, therefore you have to re-arrange your data starting with December measurements, and to adjust the epw header, e.g.:


DATA PERIODS,1,6,Period1,Tuesday,12/17, 1/27

In your case the weather data therefore start in 2013 and end in 2014, and the date entries (yyyy,mm,dd,hh,mm) have to be corrected accordingly.

After performing all corrections I succeeded in running a simulation with your weather data, and you can assess whether you agree with the following outdoor temperature chart:

image description

By the way, although times given by 1,60 or 2,60 etc. apparently are accepted by EnergyPlus, I still changed times 1:60, 2:60,.... to 2:00, 3:00,... respectively, after I discovered more inconsistencies in your data. Furthermore, with 6 weather measurements per hour you also need to run the simulation with 6 timesteps per hour.

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@OS-user-AT thank you very much for your help - i changed your notes. The reason for the missing data: I run simulations from December - January. If I run a simulation for instance from 1-2January, I get the following error message: Unexpected error condition in middle of reading EPW file, 2013/1/12:0

update: I added a frist row with start 2013,1,1,1,0 now i can run simulations that start with 1 January - but still get an error if i try to run simualtions in december

gerald gravatar image gerald  ( 2015-12-03 06:20:29 -0600 )edit

@OS-user-AT great Thank you so much!!!!! Would it be possible, that you send me the weatherfile? Is a lower stepsize also possible (I would need 2min)?

gerald gravatar image gerald  ( 2015-12-07 04:21:54 -0600 )edit

2min timesteps should also be possible, (30 timesteps per hour), however, this would probably increase simulation run time significantly, because the idf file then must be run also with 30 timesteps per hour. If you publish your email address on unmethours, I can send you the above tested epw file.

OS-user-AT gravatar image OS-user-AT  ( 2015-12-07 05:40:27 -0600 )edit

great - thank you;

gerald gravatar image gerald  ( 2015-12-07 09:01:08 -0600 )edit

@OS-user-AT - would be really great, if you could send it (, if that does not work: thank you very much

gerald gravatar image gerald  ( 2015-12-09 12:12:08 -0600 )edit

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Asked: 2015-12-02 11:39:12 -0600

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Last updated: Dec 04 '15