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White Box DDY files have multiple numbers per field

asked 2019-08-29 20:08:44 -0500

mldichter gravatar image

updated 2019-08-30 11:02:38 -0500

I'm finding these lines in the DesignDay fields

0.4  0.5, !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph)
16.6  15.5,      !- Wetbulb at Maximum Dry-Bulb {C}

As you can see, there are two numbers specified, which EnergyPlus complains about. Does anyone know what "traditional" means? I think the left number is recommended by White Box and the right number is outdated, but that's just a guess.

POST SCRIPT
From SACRAMENTO-EXECUTIVE_724830_CZ2010.ddy which was downloaded more than a year ago.

SizingPeriod:DesignDay,
  SACRAMENTO-EXECUTIVE-ARP Ann Htg 99.6% Condns DB,     !- Name
          1,      !- Month
         21,      !- Day of Month
  WinterDesignDay,!- Day Type
       -0.2,      !- Maximum Dry-Bulb Temperature {C}
        0.0,      !- Daily Dry-Bulb Temperature Range {C}
 DefaultMultipliers, !- Dry-Bulb Temperature Range Modifier Type
           ,      !- Dry-Bulb Temperature Range Modifier Schedule Name
    Wetbulb,      !- Humidity Condition Type
       -0.2,      !- Wetbulb at Maximum Dry-Bulb {C}
           ,      !- Humidity Indicating Day Schedule Name
           ,      !- Humidity Ratio at Maximum Dry-Bulb {kgWater/kgDryAir}
           ,      !- Enthalpy at Maximum Dry-Bulb {J/kg}
           ,      !- Daily Wet-Bulb Temperature Range {deltaC}
     101277,      !- Barometric Pressure {Pa}
        0.4  0.5,      !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph)
         90,      !- Wind Direction {Degrees; N=0, S=180}
         No,      !- Rain {Yes/No}
         No,      !- Snow on ground {Yes/No}
         No,      !- Daylight Savings Time Indicator
  ASHRAEClearSky, !- Solar Model Indicator
           ,      !- Beam Solar Day Schedule Name
           ,      !- Diffuse Solar Day Schedule Name
           ,      !- ASHRAE Clear Sky Optical Depth for Beam Irradiance (taub)
           ,      !- ASHRAE Clear Sky Optical Depth for Diffuse Irradiance (taud)
       0.00;      !- Clearness {0.0 to 1.1}

SizingPeriod:DesignDay,
  SACRAMENTO-EXECUTIVE-ARP Ann Clg 0.4% Condns DB=>MCWB,     !- Name
          7,      !- Month
         21,      !- Day of Month
  SummerDesignDay,!- Day Type
       37.9,      !- Maximum Dry-Bulb Temperature {C}
       17.4,      !- Daily Dry-Bulb Temperature Range {C}
 DefaultMultipliers, !- Dry-Bulb Temperature Range Modifier Type
           ,      !- Dry-Bulb Temperature Range Modifier Schedule Name
    Wetbulb,      !- Humidity Condition Type
       21.1  21.1,      !- Wetbulb at Maximum Dry-Bulb {C}
           ,      !- Humidity Indicating Day Schedule Name
           ,      !- Humidity Ratio at Maximum Dry-Bulb {kgWater/kgDryAir}
           ,      !- Enthalpy at Maximum Dry-Bulb {J/kg}
           ,      !- Daily Wet-Bulb Temperature Range {deltaC}
     101277,      !- Barometric Pressure {Pa}
        3.4  3.4,      !- Wind Speed {m/s} design conditions vs. traditional 3.35 m/s (7 mph)
        270,      !- Wind Direction {Degrees; N=0, S=180}
         No,      !- Rain {Yes/No}
         No,      !- Snow on ground {Yes/No}
         No,      !- Daylight Savings Time Indicator
       ASHRAETau, !- Solar Model Indicator
           ,      !- Beam Solar Day Schedule Name
           ,      !- Diffuse Solar Day Schedule Name
      0.382,      !- ASHRAE Clear Sky Optical Depth for Beam Irradiance (taub)
      2.325;      !- ASHRAE Clear Sky Optical Depth for Diffuse Irradiance (taud)

SizingPeriod:DesignDay,
  SACRAMENTO-EXECUTIVE-ARP Ann Clg 1% Condns DB=>MCWB,     !- Name
          7,      !- Month
         21,      !- Day of Month
  SummerDesignDay,!- Day Type
       36.2,      !- Maximum Dry-Bulb Temperature {C}
       17.4,      !- Daily Dry-Bulb Temperature Range {C}
 DefaultMultipliers, !- Dry-Bulb Temperature Range Modifier Type
           ,      !- Dry-Bulb Temperature Range Modifier Schedule Name
    Wetbulb,      !- Humidity Condition Type
       20.7  20.4,      !- Wetbulb at Maximum Dry-Bulb {C}
           ,      !- Humidity Indicating Day Schedule Name
           ,      !- Humidity Ratio at Maximum Dry-Bulb {kgWater/kgDryAir}
           ,      !- Enthalpy at Maximum Dry-Bulb {J/kg}
           ,      !- Daily Wet-Bulb Temperature Range {deltaC}
     101277,      !- Barometric Pressure {Pa}
        3 ...
(more)
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Comments

@Joe Huang I noticed you in my preliminary searches. Do you know what the pairs of numbers mean?

mldichter gravatar imagemldichter ( 2019-08-29 20:10:08 -0500 )edit
2

@mldichter can you paste a full SizingPeriod:DesignDay exhibiting this please?

Julien Marrec gravatar imageJulien Marrec ( 2019-08-30 04:11:05 -0500 )edit

@Julien Marrec I added some example objects to the post. I can't imagine anyone at my work modified the file like this, but that is a possibility. We also downloaded these files quite a while ago. For now, I just deleted the right number, leaving what I think is the White Box recommended number.

mldichter gravatar imagemldichter ( 2019-08-30 11:05:57 -0500 )edit

@Julien Marrec@Joe Huang Any idea what the pairs of numbers are? Are my DDY files simply outdated?

mldichter gravatar imagemldichter ( 2019-09-06 10:18:16 -0500 )edit
1

I'd recommend just contacting whitebox (=Joe) directly: http://weather.whiteboxtechnologies.c...

Julien Marrec gravatar imageJulien Marrec ( 2019-09-10 03:16:33 -0500 )edit

1 Answer

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answered 2019-09-10 15:23:09 -0500

Joe Huang gravatar image

It took a bit of backtracking, but I finally found an old 2015 version of the calcdsntempAEC.program I wrote that included the dual set of numbers, and even then they had been commented out! I had written the calcdsntempAEC program to calculate the DDY files so that they would be consistent with the CZ2010 weather files.

During development I added a lot of debug statements to make sure the values are correctly calculated, and the two variables you pointed out with duplicate numbers (Wind Speed and Mean Coincident Wet Bulb) were case where I had inadvertently left in the second debug output. Base don reading the program code, the first number is the one that should be used, while the second number is a debug value calculated in a different way. Most of the time the two are either the same or within a point of each other.

I could only find such DDY files for the CZ2010 weather files. I've corrected all 86 of the CZ2010 zip files, so if you were to download the files again, the DDY files should no longer show the duplicate numbers.

Joe

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Asked: 2019-08-29 20:08:44 -0500

Seen: 205 times

Last updated: Sep 10