[solved] [urgent] error probably related to wrongly written IDF file on the class of SizingPeriod

old forum
1

For the attached simple demo file, I got the following errors when running EnergyPlus simulation:

** ** Severe ** IP: IDF line~48 Invalid Number in Numeric Field#7 (Enthalpy at Maximum Dry-Bulb ), value=WINTERDESIGNDAY, in SIZINGPERIOD:DESIGNDAY=SINGAPORE ANN HTG 99.6% CONDNS DB**
** ************* IDF Context for following error/warning message:
** ************* Note – lines truncated at 300 characters, if necessary…
** ************* 53 SizingPeriod:DesignDay,
** ************* indicated Name=SINGAPORE Ann Htg 99% Condns DB
** ************* Only last 10 lines before error line shown…
** ************* 57 23.5, !- Humidity Indicating Conditions at Maximum Dry-Bulb
** ************* 58 101133., !- Barometric Pressure {Pa}
** ************* 59 2, !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph)
** ************* 60 320, !- Wind Direction {Degrees; N=0, S=180}
** ************* 61 0.00, !- Clearness {0.0 to 1.1}
** ************* 62 0, !- Rain {0-no,1-yes}
** ************* 63 0, !- Snow on ground {0-no,1-yes}
** ************* 64 21, !- Day of Month**
** ************* 65 12, !- Month**
** ************* 66 WinterDesignDay,!- Day Type**

The relevant lines in the IDF file is shown below:

** SizingPeriod:DesignDay,
** SINGAPORE Ann Htg 99.6% Condns DB, !- Name
** 23, !- Maximum Dry-Bulb Temperature {C}
** 0.0, !- Daily Temp Range {C}
** 23, !- Humidity Indicating Conditions at Maximum Dry-Bulb**
** 101133., !- Barometric Pressure {Pa}
** 2, !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph)
** 320, !- Wind Direction {Degrees; N=0, S=180}
** 0.00, !- Clearness {0.0 to 1.1}
** 0, !- Rain {0-no,1-yes}
** 0, !- Snow on ground {0-no,1-yes}
** 21, !- Day of Month**
** 12, !- Month**
** WinterDesignDay,!- Day Type**
** 0, !- Daylight Savings Time Indicator**
** WetBulb; !- Humidity Indicating Type**
**
** ! SINGAPORE_SGP Annual Heating 99%, MaxDB=23.5°C
** SizingPeriod:DesignDay,
** SINGAPORE Ann Htg 99% Condns DB, !- Name
** 23.5, !- Maximum Dry-Bulb Temperature {C}
** 0.0, !- Daily Temp Range {C}
** 23.5, !- Humidity Indicating Conditions at Maximum Dry-Bulb**
** 101133., !- Barometric Pressure {Pa}
** 2, !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph)
** 320, !- Wind Direction {Degrees; N=0, S=180}
** 0.00, !- Clearness {0.0 to 1.1}
** 0, !- Rain {0-no,1-yes}
** 0, !- Snow on ground {0-no,1-yes}
** 21, !- Day of Month**
** 12, !- Month**
** WinterDesignDay,!- Day Type**
** 0, !- Daylight Savings Time Indicator**
** WetBulb; !- Humidity Indicating Type**

It seems that there is an empty line after the line for “!- Humidity Indicating Type” field, and nothing is specified for “! SINGAPORE_SGP Annual Heating 99%, MaxDB=23.5°C” field.

May I ask why this happens and how to correct the error?

Thank you very much!

AR4322_tutorial_1_v055.gh (577 KB)

2

FYI, the IDF file and the error file are also attached.

house_01_withBlinds_noContext.idf (92.6 KB)
house_01_withBlinds_noContext.err (23.4 KB)

3

Hi Grasshope,

I believe the issue is worst than what you submitted.

I have to say that i open the idf with E+8.3 Launcher. The idf version is 8.4, but i don’t think thinks have changed so much for the following:

See attached. As you can see the requirements of the editor are completely different than those of the supplied in the idf. Some inputs are mismatched and some inputs are missing (those in blue).

Maybe this is caused by the recent changes Chris implemented with OpenStudio stuff. I don’t know. I would report this issue in the github.

-A.


4

Thank you very much, Abraham!

Yes, as you find out, the IDF file generated for EP v.8.4 can still be executed in EP Launch for v8.3.

So, some file format stuff might have gone wrong in the latest Honeybee when writing out the IDF file.

Hope this can be fixed soon.

Meanwhile, I’ll suggest our student to run the IDF file in EP 8.3.

5

I don’t believe this file can be run in EP8.3. As i pointed out the formating for the SizingPeriod doesn’t fit the required fields.

You can open the file with the launcher but the simulation will fail.

-A.

6

Grasshope and Abraham,

I apologize for the late response here. I just finished teaching a workshop on LB with Mostapha and I have a lot to catch up on here. I know that this error is related to the fact that I recently switched the Run Simulation component to use the design days in the ddy file instead of the previous sizing, which was done based on extreme periods in the EPW. Using the ddy file is better practice than sizing based on extreme EPW periods but I did not test out the new workflow for all ddy files. It seems that some formats of ddy files may cause this error. I am travelling now but I will gix this issue as soon as I get back in ~14 hours. In the meantime, I would strongly recommend using the OpenStudio component instead of the run simulation component. The OpenStudio component currently has all of the features of the run simulation component and, over the next few months, we will begin phasing out the run simulation component to focus all development on OpenStudio. The reason is that OpenStudio allows us to model the HVAC, which is now fully-functional in the OpenStudio component.

-Chris

7

Also, if you test out your files with OpenStudio, please let me know the result here. I imagine that it should run smoothly but I am not positive.

8

Yes, Chris, replacing the Run Simulation component with the Export_to_OpenStudio component solves the problem I reported.

Thank you very much for you advice!

The revised example file is attached here, too.

AR4322_tutorial_1_v056_OpenStudioComponent.gh (625 KB)

9

Dear Chris,

Thank you very much for your hard work to update the components which work fine now!

I noticed that the ddy file generated by the Run Simulation or the Export to OpenStudio components, in the case when only the EPW file is present, is different from the original ddy file downloaded from energyplus.net, at least for the Singapore EPW file. (both files attached)

The image attached shows the difference btw the original and the generated ddy files in terms of variables such as Maximum Dry-Bulb Temperature, Humidity Condition Type, Wetbulb or Dewpoint at Maximum Dry-Bulb, Barometric Pressure, Wind Speed, Wind Direction.

May I ask if these differences matter in the simulation, especially when using Ideal Loads Air System?

Will you recommend to always put the original ddy and epw files side by side in the same folder when conducting simulation?

Thank you!

SGP_Singapore_generated.ddy (9.08 KB)
SGP_Singapore.486980_IWEC.ddy (28 KB)

10

Hi Grasshope,

Glad that everything has been running smoothly. To answer your question:

Yes, the original ddys issued by ASHRAE are different than those that are generated by the Energy Simulation components. However, they are very close to each other and my inference as to why they are not perfectly equal is that the ddys for ASHRAE/DoE are likely built using all of the collected weather data over the (at least) 18 years that a weather station has been recording data. In contrast, the Energy Simulation components use the same statistical methods but on just the data with in the epw, which is just one year (albeit a ‘typical’ year statistically).

You should keep in mind that what E+ is trying to do with the ddy file and autosizing of the HVAC is mimic the process that an engineer undergoes to size specify your building’s HVAC system and there can be variations in techniques for sizing the HVAC just as there can be differences between the weather in an epw and that which a building actually experiences once it is built. Still, it’s probably safe to say that, if an engineer has a ddy file that is issued by ASHRAE, they will probably use that to size the system instead of a ddy file generated just from the epw. As such, it’s a good idea to include the ddy file next to the epw if you have it as this is closer to what an engineer might do.

All of this said, in the cases that I tested, the minor differences between the ASHRAE ddy and that generated by the Energy Simulation components had a negligible effect on the resulting heating and cooling values out of E+. I was often able to get the heating energy to match down to the kWh and the cooling energy matched within 1-2%. The cooling sizing is off because the Sky model for radiation used by AHSRAE in the ddy files (ASHRAEtau method) requires some information not contained in the EPW. Instead, I use ASHRAE’s simpler ClearSky model at the highest solar intensity. As a result, the function here oversizes the cooling system by small amount (1-2% as mentioned previously).

-Chris

11

Thank you very much, Chris, for the detailed clarification!

We shall use the ddy file came with the epw file from energyplus.net as suggested.