Reports/Files Produced by the Weather Converter[LINK]

Minimally, two outputs are produced for every weather converter run: an audit / log file and a statistical report file. The audit / log file shows details of the processing (including any errors) as well as the statistical report. The statistical report produced from the weather conversion process is a short, but complete, picture of the weather data on the file. A single file (.stat extension) is produced of the “statistics” about the data file. A feature of the weather converter is to look in several design condition files for possible design conditions for the location from the stored design condition files (source: ASHRAE Handbook of Fundamentals, 2001). If found (WMO (World Meteorological Organization) id is used for matching), these will be shown in the report as well as included in the output data files (EPW and CSV, as applicable). In addition, the Köppen classification scheme is used to characterize the climate based on the data file’s contents. Other statistics are given as well to help you visualize the data.

In the “reporting” section of the file, each line contains “tab-delimited” elements. This will allow you to easily place the data into a spreadsheet program for further refinement but the tabs are not as intrusive for “normal viewing” as commas.

Audit / Log File[LINK]

As an example, the initial portion of an audit file is shown (illustrating the error reporting):

-Input File Type=WY2, with FileName=D:\DevTests\Release\WeatherData\04772.wy2
     -Out of Range Data items will NOT be corrected.
     Warning ** Dew Point=   5.00°C > Dry Bulb=   4.90°C on date= 5/ 1 at hour= 4
     Warning ** Dew Point=   4.80°C > Dry Bulb=   4.40°C on date= 5/ 1 at hour= 5
     Warning ** Dew Point=   4.70°C > Dry Bulb=   3.80°C on date= 5/ 1 at hour= 6
     Warning ** Suspected missing data line after processing          365  days
      Month=           0  Day=           0  Hour=           0
      Processing continues but may be in error
     Warning ** Suspected Blank line after processing          365  days
     ** Remaining records, if any, will be ignored
     Warning ** Missing Data Found on Source Weather Data File
     ** Missing (and corrected) Aerosol Optical Depth, Number of items= 8760
     Warning ** Out of Range Data Found on Weather Data File
     ** Out of Range Dew Point Temperatures > Dry Bulb Temperatures, Number of items=    3

- Start Date/End Date for Weather Source
     Start Date=Jan  1; End Date=Dec 31

- Actual Data Years for Monthly Data**
               JanFebMarAprMayJunJulAugSepOctNovDec
              1966 1980 1964 1964 1968 1970 1977 1981 1979 1969 1974 1960
- ** Not all weather data sources represent contiguous years.
- ** Monthly data values may come from different years.

- Data Sources should be checked for relevancy to these statistics.

     Average Delta DB Change=  0.76°C ; Std Dev=  0.73°C
     Average Delta DP Change=  0.62°C ; Std Dev=  0.69°C
     Average Delta Relative Humidity Change=  3.50% ; Std Dev=  3.63%
     Average Delta Wind Speed Change=  0.93m/s ; Std Dev=  0.88m/s
     Hourly Dry Bulb temperature change trigger = minimum of  11.07°C  and  10.°C
         11.07°C = calculated trigger based on mean change in dry-bulb temperature and standard deviation shown above
         10.°C = trigger set by user

     -Output File Type=epw, with FileName=D:\DevTests\Release\WeatherData\Out\CAN_Ottawa-International_Airport_CWEC.epw
     -Output File Type=csv, with FileName=D:\DevTests\Release\WeatherData\Out\CAN_Ottawa-International_Airport_CWEC.csv

Statistical Report File[LINK]

As will be seen in comparison with a “statistical” report shown following, the audit file may contain some details about the data that the statistical report does not (such as the data years for the weather data). Some basic statistics are shown first:

Statistics for USA_CA_San.Francisco.Intl.AP.724940_TMY3
 Location -- San Francisco Intl Ap CA USA
      {N 37° 37'} {W 122° 24'} {GMT -8.0 Hours}
 Elevation --     2m above sea level
 Standard Pressure at Elevation -- 101301Pa
 Data Source -- TMY3

 WMO Station 724940

- Displaying Design Conditions from "Climate Design Data 2009 ASHRAE Handbook"
 - ASHRAE design conditions are carefully generated from a period of record
 - (typically 30 years) to be representative of that location and to be suitable
 - for use in heating/cooling load calculations.

        Design Stat ColdestMonth    DB996   DB990   DP996   HR_DP996    DB_DP996    DP990   HR_DP990    DB_DP990    WS004c  DB_WS004c   WS010c  DB_WS010c   WS_DB996    WD_DB996
        Units   {}  {°C}    {°C}    {°C}    {}  {°C}    {°C}    {}  {°C}    {m/s}   {°C}    {m/s}   {°C}    {m/s}   {deg}
        Heating 1   3.8 4.9 -3.7    2.8 10.7    -1.2    3.4 11.2    12.9    12.1    11.6    12.2    2.2 150

        Design Stat HottestMonth    DBR DB004   WB_DB004    DB010   WB_DB010    DB020   WB_DB020    WB004   DB_WB004    WB010   DB_WB010    WB020   DB_WB020    WS_DB004    WD_DB004    DP004   HR_DP004    DB_DP004    DP010   HR_DP010    DB_DP010    DP020   HR_DP020    DB_DP020    EN004   DB_EN004    EN010   DB_EN010    EN020   DB_EN020    #Hrs_8-4_&_DB-12.8/20.6
        Units   {}  {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {m/s}   {deg}   {°C}    {}  {°C}    {°C}    {}  {°C}    {°C}    {}  {°C}    {kJ/kg} {°C}    {kJ/kg} {°C}    {kJ/kg} {°C}    {}
        Cooling 8   8.5 28.3    17.2    25.7    16.7    23.6    16.2    18.6    25.7    17.8    23.9    17  22.4    5.9 310 16.1    11.5    19.9    15.3    10.9    19.2    14.7    10.4    18.7    52.4    25.8    49.8    23.8    47.6    22.4    2038

        Design Stat WS010   WS025   WS050   WBmax   DBmin_mean  DBmax_mean  DBmin_stddev    DBmax_stddev    DBmin05years    DBmax05years    DBmin10years    DBmax10years    DBmin20years    DBmax20years    DBmin50years    DBmax50years
        Units   {m/s}   {m/s}   {m/s}   {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}    {°C}
        Extremes    12.8    11.5    10.6    22.3    1.8 34.6    1.5 2.3 0.8 36.2    -0.1    37.5    -0.9    38.8    -1.9    40.5

 - Displaying Monthly Design Conditions "Climate Design Data 2009 ASHRAE Handbook"
 - Monthly Optical Sky Depth Beam (taub) and Diffuse (taud)
                                Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
                 taub (beam)    0.316   0.326   0.334   0.362   0.368   0.353   0.371   0.365   0.352   0.335   0.320   0.318
              taud (diffuse)    2.608   2.528   2.525   2.345   2.360   2.496   2.395   2.435   2.518   2.545   2.611   2.538

                        taub    = Clear Sky Optical Depth for Beam Irradiance
                        taud    = Clear Sky Optical Depth for Diffuse Irradiance

 - Monthly Solar Irradiance Wh/m² (noon on 21st of month)
                   ib (beam)      879     910     933     918     912     923     903     904     901     887     866     846
                id (diffuse)       79      93     100     124     123     108     118     112      99      90      78      80

                          ib    = Clear Sky Noon Beam Normal Irradiance on 21st Day
                          id    = Clear Sky Noon Diffuse Horizontal Irradiance on 21st Day


 - Monthly Drybulb and Mean Coincident Wetbulb Temperatures °C
                                Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
                Drybulb 0.4%     17.8    21.1    23.3    26.9    28.3    31.5    29.4    29.2    31.1    29.5    22.7    17.5
     Coincident Wetbulb 0.4%     12.1    13.9    14.4    16.2    17.3    17.7    18.4    18.2    18.0    16.5    14.0    12.9
                Drybulb 2.0%     15.8    17.9    19.8    22.5    23.7    25.6    25.3    25.0    27.1    25.5    20.0    16.2
     Coincident Wetbulb 2.0%     12.1    12.7    13.4    14.4    15.8    16.7    17.3    17.5    17.1    15.6    13.5    13.0
                Drybulb 5.0%     14.6    16.2    17.6    19.5    21.1    22.3    22.7    22.9    23.9    22.6    18.2    15.2
     Coincident Wetbulb 5.0%     11.8    12.6    13.0    13.6    15.1    15.8    16.5    16.8    16.6    15.2    13.4    12.5
                Drybulb 10.%     13.5    15.0    16.2    17.5    19.1    20.6    21.2    21.5    21.8    20.5    16.8    14.2
     Coincident Wetbulb 10.%     11.2    12.1    12.5    12.9    14.1    15.1    15.9    16.2    16.1    14.9    13.3    11.7

                Drybulb 0.4%    = 0.4% Monthly Design Drybulb Temperature
     Coincident Wetbulb 0.4%    = 0.4% Monthly Mean Coincident Wetbulb Temperature
                Drybulb 2.0%    = 2.0% Monthly Design Drybulb Temperature
     Coincident Wetbulb 2.0%    = 2.0% Monthly Mean Coincident Wetbulb Temperature
                Drybulb 5.0%    = 5.0% Monthly Design Drybulb Temperature
     Coincident Wetbulb 5.0%    = 5.0% Monthly Mean Coincident Wetbulb Temperature
                Drybulb 10.%    = 10.% Monthly Design Drybulb Temperature
     Coincident Wetbulb 10.%    = 10.% Monthly Mean Coincident Wetbulb Temperature

- Monthly Drybulb and Mean Coincident Wetbulb Temperatures °C
                             JanFebMarAprMayJunJulAugSepOctNovDec
                 Drybulb 0.4% 17.8 21.1 23.3 26.9 28.3 31.5 29.4 29.2 31.1 29.5 22.7 17.5
      Coincident Wetbulb 0.4% 12.1 13.9 14.4 16.2 17.3 17.7 18.4 18.2 18.0 16.5 14.0 12.9
                 Drybulb 2.0% 15.8 17.9 19.8 22.5 23.7 25.6 25.3 25.0 27.1 25.5 20.0 16.2
      Coincident Wetbulb 2.0% 12.1 12.7 13.4 14.4 15.8 16.7 17.3 17.5 17.1 15.6 13.5 13.0
                 Drybulb 5.0% 14.6 16.2 17.6 19.5 21.1 22.3 22.7 22.9 23.9 22.6 18.2 15.2
      Coincident Wetbulb 5.0% 11.8 12.6 13.0 13.6 15.1 15.8 16.5 16.8 16.6 15.2 13.4 12.5
                 Drybulb 10.% 13.5 15.0 16.2 17.5 19.1 20.6 21.2 21.5 21.8 20.5 16.8 14.2
      Coincident Wetbulb 10.% 11.2 12.1 12.5 12.9 14.1 15.1 15.9 16.2 16.1 14.9 13.3 11.7

                 Drybulb 0.4%= 0.4% Monthly Design Drybulb Temperature
      Coincident Wetbulb 0.4%= 0.4% Monthly Mean Coincident Wetbulb Temperature
                 Drybulb 2.0%= 2.0% Monthly Design Drybulb Temperature
      Coincident Wetbulb 2.0%= 2.0% Monthly Mean Coincident Wetbulb Temperature
                 Drybulb 5.0%= 5.0% Monthly Design Drybulb Temperature
      Coincident Wetbulb 5.0%= 5.0% Monthly Mean Coincident Wetbulb Temperature
                 Drybulb 10.%= 10.% Monthly Design Drybulb Temperature
      Coincident Wetbulb 10.%= 10.% Monthly Mean Coincident Wetbulb Temperature

Or, if the weather converter must calculate the design stats:

-EnergyPlus Weather Converter V7.1.0.010
     Statistics for FaroCST
     Location -- Faro - PRT
          {N 37°  2'} {E   7° 55'} {GMT +0.0 Hours}
     Elevation --   100m above sea level
     Standard Pressure at Elevation -- 100129Pa
     Data Source -- Custom-085790

     WMO Station 085790

- Displaying Design Conditions calculated from this weather file.
-  The following design temperature statistics are calculated based on THIS weather file ONLY
-  and may not be representative of a long-term  period of record normally used for
-  design temperatures. Also, note that dew point temperatures are listed where
-  wet-bulb temperatures are normally presented.

     Design StatColdest MonthHDB 99.6%HDB 99%
        Units       {}      {C}     {C}
       Heating   3  5.6  6.0

     Design StatHottest MonthCDB .4%CDB 1%CDB 2%CDP .4%CDP 1%CDP 2%
        Units       {}     {C}    {C}   {C}   {C}    {C}   {C}
       Cooling   8 33.3 32.5 31.8 22.6 22.0 21.7

     Design StatJanFebMarAprMayJunJulAugSepOctNovDec
        Units   {m/s}{m/s}{m/s}{m/s}{m/s}{m/s}{m/s}{m/s}{m/s}{m/s}{m/s}{m/s}
     Max WS  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0

- Heating/Cooling Degree Days/Hours calculated from this weather file are later in this report.

These are followed by groupings of Monthly temperature data.

- Monthly Statistics for Dry Bulb temperatures °C
               JanFebMarAprMayJunJulAugSepOctNovDec
    Maximum  16.7 22.2 23.9 28.3 29.4 32.8 26.7 29.4 30.0 26.7 20.6 16.1
     Day:Hour19:1314:1312:15 2:15 1:1230:1412:13 2:1315:1420:14 1:14 1:15

    Minimum   2.2  5.0  4.4  8.3  8.9  9.4 11.1 11.1 11.1  7.8  3.3  2.8
     Day:Hour24:0626:0723:0519:05 4:0222:03 1:0428:05 7:0231:0530:0526:05

    Daily Avg9.6  11.3 12.7 13.7 15.0 15.3 15.9 16.6 16.7 15.1 12.8 10.7

- Maximum Dry Bulb temperature of  32.8°C on Jun 30
- Minimum Dry Bulb temperature of   2.2°C on Jan 24

- Monthly Statistics for Extreme Dry Bulb temperatures °C
      #Days  JanFebMarAprMayJunJulAugSepOctNovDec
    Max >= 32                             1
    Max <=  0
    Min <=  0
    Min <=-18

- Monthly Statistics for Dew Point temperatures °C
               JanFebMarAprMayJunJulAugSepOctNovDec
    Maximum 13.3 12.2 13.9 15.0 16.7 16.1 14.0 16.7 16.7 14.4 14.4 13.9
     Day:Hour17:1221:0429:15 2:1414:09 5:12 8:14 3:1023:12 6:1411:12 7:03

    Minimum -1.1 0.6  -1.1 -0.6 0.0  5.0  6.1  4.4  7.8  -1.7 -3.3 -5.6
     Day:Hour24:0524:0712:1512:13 2:1718:17 2:1330:1215:1716:2121:2119:12

    Daily Avg6.4  6.6  8.1  8.2  9.4  10.0 10.7 11.5 12.5 9.4  8.3  6.1

- Maximum Dew Point temperature of  16.7°C on May 14
- Minimum Dew Point temperature of  -5.6°C on Dec 19

For the dry bulb and dew point temperatures, an average hourly report, by month, is also given:

- Average Hourly Statistics for Dry Bulb temperatures °C
               JanFebMarAprMayJunJulAugSepOctNovDec
     0:01- 1:00  8.9  9.9 10.6 11.6 12.3 12.1 13.4 14.0 14.4 13.3 11.6  9.7
     1:01- 2:00  8.7  9.5 10.3 11.4 12.1 12.0 13.2 13.7 14.3 12.7 11.2  9.4
     2:01- 3:00  8.3  9.0 10.1 11.3 12.0 11.7 13.1 13.5 14.1 12.4 11.0  9.2
     3:01- 4:00  7.8  8.6 10.0 11.2 12.0 11.6 12.9 13.4 14.0 12.4 11.1  8.9
     4:01- 5:00  7.9  8.5  9.7 11.0 11.8 11.5 13.4 13.3 13.8 12.0 10.6  8.7
     5:01- 6:00  7.8  8.4  9.6 11.3 12.4 12.3 13.8 13.5 13.9 12.2 10.8  8.5
     6:01- 7:00  7.9  8.3  9.8 12.2 14.0 14.1 14.3 14.9 14.6 12.5 10.9  8.5
     7:01- 8:00  7.9  9.2 11.5 13.1 15.5 15.7 15.4 16.3 16.1 14.3 11.5  8.9
     8:01- 9:00  8.8 10.1 12.6 14.1 16.6 16.6 16.5 17.5 17.4 15.3 12.6  9.9
     9:01-10:00  9.5 11.0 13.7 15.0 17.7 17.7 17.5 18.4 18.5 16.1 13.2 10.9
    10:01-11:00 10.1 12.1 14.5 16.2 18.8 19.1 18.4 19.6 19.6 17.2 13.8 11.5
    11:01-12:00 10.6 13.2 15.6 16.8 19.3 19.9 19.3 20.6 20.5 18.0 14.3 11.9
    12:01-13:00 11.4 14.2 16.4 17.1 19.2 20.6 20.2 21.3 21.3 18.9 14.9 12.5
    13:01-14:00 11.5 14.5 16.9 17.0 19.0 20.5 19.8 21.5 21.4 19.2 15.4 12.9
    14:01-15:00 11.9 14.8 16.8 17.0 18.4 19.7 19.4 21.1 21.0 19.1 15.7 13.0
    15:01-16:00 11.6 15.1 16.0 16.7 17.6 18.8 19.0 20.1 19.9 18.2 15.4 13.0
    16:01-17:00 11.0 14.1 15.1 15.8 16.7 17.6 18.0 18.8 18.8 17.0 14.3 12.4
    17:01-18:00 10.6 13.1 13.8 14.4 15.7 16.6 16.9 17.4 17.0 15.8 13.7 12.0
    18:01-19:00 10.3 12.2 12.7 13.3 14.4 15.3 15.8 16.1 15.9 15.3 13.4 11.5
    19:01-20:00 10.0 11.8 12.3 12.9 13.4 13.8 15.3 15.4 15.6 14.9 13.0 11.1
    20:01-21:00  9.7 11.4 11.7 12.6 13.2 13.3 14.8 15.0 15.1 14.5 12.6 10.6
    21:01-22:00  9.6 11.0 11.6 12.3 13.0 12.9 14.2 14.7 14.8 14.2 12.1 10.4
    22:01-23:00  9.5 10.6 11.3 12.0 12.7 12.5 14.0 14.3 14.6 13.8 12.1 10.3
    23:01-24:00  9.2 10.3 11.1 11.8 12.4 12.5 13.7 14.3 14.5 13.5 11.7 10.0
     Max Hour    15   16   14   13   12   13   13   14   14   14   15   15
     Min Hour     6    7    6    5    5    5    4    5    5    5    5    6

- Average Hourly Statistics for Dew Point temperatures °C
               JanFebMarAprMayJunJulAugSepOctNovDec
     0:01- 1:00  6.7  6.6  8.0  8.1  9.5  9.7  9.9 11.4 12.3  9.7  8.0  5.7
     1:01- 2:00  6.6  6.1  7.7  8.1  9.4  9.6 10.1 11.2 12.3  9.3  8.0  5.8
     2:01- 3:00  6.3  5.9  7.4  8.2  9.3  9.4 10.0 11.2 12.2  9.1  7.6  5.9
     3:01- 4:00  5.9  5.9  7.7  8.0  9.3  9.5  9.7 11.0 12.1  8.9  8.0  5.8
     4:01- 5:00  5.9  5.6  7.6  8.0  9.2  9.4  9.9 11.0 12.1  9.1  7.6  5.5
     5:01- 6:00  5.9  5.5  7.5  8.1  9.4  9.8 10.1 11.1 12.1  9.1  7.8  5.7
     6:01- 7:00  6.0  5.7  7.6  8.5  9.7 10.3 10.2 11.6 12.4  9.5  7.8  5.8
     7:01- 8:00  5.9  6.1  8.4  8.8  9.7 10.6 10.8 11.8 12.7 10.4  7.9  6.1
     8:01- 9:00  6.1  6.8  8.8  9.0 10.0 10.8 11.0 12.1 12.9 10.4  8.2  6.3
     9:01-10:00  6.1  7.3  8.8  8.9  9.7 10.9 11.0 12.4 13.2 10.4  8.1  6.3
    10:01-11:00  6.4  7.1  8.5  8.7  9.8 10.8 11.4 12.0 13.4  9.9  8.3  6.2
    11:01-12:00  6.3  6.8  8.3  8.6  9.5 10.6 11.5 11.8 13.3  9.7  8.1  6.2
    12:01-13:00  6.2  6.9  8.3  8.5  9.4 10.5 11.5 11.6 12.8  9.2  8.3  6.5
    13:01-14:00  6.3  6.8  8.0  8.7  9.2 10.2 11.6 11.5 12.6  9.3  8.4  6.6
    14:01-15:00  6.4  7.1  8.4  8.1  9.2 10.1 11.5 11.4 12.4  8.8  8.7  6.4
    15:01-16:00  6.6  7.6  8.0  7.7  9.0  9.9 11.4 11.2 12.4  8.9  8.6  6.3
    16:01-17:00  6.6  7.1  7.9  7.8  9.0  9.7 11.2 11.4 12.3  9.0  9.3  6.7
    17:01-18:00  6.6  6.8  7.9  7.8  9.1  9.6 11.0 11.4 12.3  8.9  9.4  6.7
    18:01-19:00  6.5  6.7  7.9  7.9  9.4  9.6 10.6 11.4 12.3  9.0  9.1  6.7
    19:01-20:00  6.5  6.5  7.9  8.0  9.3  9.6 10.7 11.5 12.4  9.2  8.9  6.3
    20:01-21:00  6.6  6.6  8.2  7.7  9.5  9.6 10.6 11.5 12.4  9.3  8.5  6.2
    21:01-22:00  6.8  6.8  8.0  8.1  9.5  9.7 10.2 11.4 12.5  9.5  8.6  6.0
    22:01-23:00  6.7  6.6  8.3  8.0  9.7  9.7 10.4 11.5 12.4  9.6  8.4  6.1
    23:01-24:00  6.6  6.5  8.4  8.1  9.6  9.6 10.3 10.7 12.4  9.4  8.5  5.9
     Max Hour    22   16    9    9    9   10   14   10   11    9   18   19
     Min Hour     6    6    3   16   16    5    4   24    4   15    3    5

Humidity/precipitation: Relative Humidity (both monthly and average hourly by month)

- Monthly Statistics for Relative Humidity %
               JanFebMarAprMayJunJulAugSepOctNovDec
    Maximum    100   96   96  100  100   96   93   96  100   96   96  100
     Day:Hour  7:05 6:0420:22 9:0325:02 5:0118:04 7:02 4:07 7:0711:07 7:05

    Minimum     23   30   22   24   25   30   25   36   19   20   32   25
     Day:Hour 17:1514:13 4:16 5:10 9:1217:10 2:1314:1328:1530:1320:1524:15

    Daily Avg   77   75   70   72   73   73   71   74   72   73   74   79

- Average Hourly Relative Humidity %
               JanFebMarAprMayJunJulAugSepOctNovDec
     0:01- 1:00   83   81   77   81   85   84   83   86   84   81   81   84
     1:01- 2:00   84   82   75   80   87   84   83   86   85   82   81   85
     2:01- 3:00   86   83   76   83   88   85   83   87   85   82   82   86
     3:01- 4:00   87   84   78   82   87   85   83   87   85   83   83   85
     4:01- 5:00   88   84   79   83   88   83   81   88   85   83   83   86
     5:01- 6:00   89   84   80   83   88   81   80   88   85   83   83   86
     6:01- 7:00   89   84   80   79   81   80   78   84   82   83   83   86
     7:01- 8:00   88   82   75   73   74   75   73   77   78   78   79   86
     8:01- 9:00   83   81   70   70   68   69   68   71   71   74   74   82
     9:01-10:00   77   79   68   65   64   64   62   67   65   70   70   79
    10:01-11:00   74   74   65   62   59   62   59   60   59   65   66   76
    11:01-12:00   69   69   59   60   55   60   56   57   54   60   63   73
    12:01-13:00   65   63   58   59   53   58   53   55   52   55   59   71
    13:01-14:00   62   63   58   60   54   59   55   55   54   56   61   68
    14:01-15:00   61   63   58   60   56   60   56   57   56   58   62   67
    15:01-16:00   61   62   59   62   59   60   58   61   58   59   64   69
    16:01-17:00   66   65   62   63   62   65   62   63   63   64   67   74
    17:01-18:00   71   68   67   66   67   69   67   69   67   69   70   76
    18:01-19:00   74   71   71   69   73   74   72   75   73   73   73   76
    19:01-20:00   77   73   72   73   79   76   75   79   76   75   74   77
    20:01-21:00   78   74   74   75   81   78   77   82   78   77   76   78
    21:01-22:00   79   76   76   76   83   80   80   83   79   78   77   79
    22:01-23:00   79   78   76   78   84   81   81   84   81   79   78   82
    23:01-24:00   82   79   76   79   84   83   82   84   82   80   80   82
     Max Hour     7    7    7    5    5    4    1    6    5    5    7    7
     Min Hour    15   16   15   13   13   13   13   13   13   13   13   15

- Monthly Indicators for Precipitation/Moisture (kPa)
               JanFebMarAprMayJunJulAugSepOctNovDec
               0.8  1.1  0.9  1.0  1.1  1.2  1.3  1.3  1.3  1.2  1.1  0.9

Wind and Wind Chill/Heat Index

- Monthly Statistics for Wind Chill/Heat Index temperatures °C **
               JanFebMarAprMayJunJulAugSepOctNovDec
    Minimum WC   -1   -1   -6   -1   -2    4                   9    0   -8
     Day:Hour19:09 2:1016:0615:04 5:24 1:23               27:0427:0428:04

    Average WC    6    7    4    5    5    6                   9    7    4
    Avg Del WC    1    2    5    3    4    4                   0    2    3
     # Hours WC  293  166  258  159   56   10                   3   86  358

    Maximum HI                                 27   28
     Day:Hour                               2:1015:11

    Average HI                                 27   28
    Avg Del HI                                  0    0
     # Hours HI                                  1    1

- **WindChill/HeatIndex Temps -- statistics...only those different from Air Temps

- Monthly Wind Direction % {N=0 or 360,E=90,S=180,W=270}
               JanFebMarAprMayJunJulAugSepOctNovDec
    North       20   11    6    5    4    3    7    6    9    8   16   27
    NorthEast   10   10    6    3    3    2    3    3    5    6    6   13
    East         8    8    6    3    2    1    1    3    3    5    9    8
    SouthEast   13    7    6    2    1    0    0    0    1    6   17   17
    South       18   10    9    5    3    1    0    1    5   14   14   12
    SouthWest    7    6   19    8    5    2    1    6    7    8   11    4
    West         9   14   31   35   32   59   21   32   22   16   10    5
    NorthWest   15   35   18   39   50   33   66   50   49   36   17   15

- Monthly Statistics for Wind Speed m/s
               JanFebMarAprMayJunJulAugSepOctNovDec
    Maximum  11.8 14.9 17.0 12.9 15.9 11.8 12.4 13.4 14.9 10.8  8.8 13.4
     Day:Hour 29:1210:22 2:15 9:1610:1710:16 4:1629:1411:1522:19 3:1027:13

    Minimum   0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0
     Day:Hour  1:04 1:10 4:04 4:19 8:0517:07 1:07 1:07 1:07 3:04 2:01 2:03

    Daily Avg  2.5  3.5  5.1  4.8  6.5  5.6  5.7  5.5  4.8  3.9  2.7  3.6

- Maximum Wind Speed of  17.0 m/s on Mar  2
- Minimum Wind Speed of   0.0 m/s on Jan  1

Rain/Albedo:

- Monthly Statistics for Liquid Precipitation mm
           JanFebMarAprMayJunJulAugSepOctNovDec
    Total   47   0    3    24   22   0    0    0    2    14   21   72

- Monthly Statistics for Albedo
               JanFebMarAprMayJunJulAugSepOctNovDec
    Average 0.1600.0000.1300.1300.1300.1400.0000.0000.1800.1800.1600.210

Solar Radiation

- Monthly Statistics for Solar Radiation  (Direct Normal, Diffuse, Global Horizontal) Wh/m²
               JanFebMarAprMayJunJulAugSepOctNovDec
    Direct Avg 2537 3829 4485 5123 5691 6743 6867 6329 6017 4178 3080 3314

    Direct Max 5405 7987 8803 8786 104621059510692102188485 7348 6194 6730
        Day      27   18   20   18   23    2   25    3   10    3    2   25

    Diffuse Avg1127 1300 1763 2344 2335 2247 2148 1998 1643 1610 1252 912

    Global Avg 2136 3160 4402 5672 6419 7148 7129 6401 5460 3761 2530 2127
- Maximum Direct Normal Solar of 10692 Wh/m² on Jul 25

- Average Hourly Statistics for Direct Normal Solar Radiation Wh/m²
               JanFebMarAprMayJunJulAugSepOctNovDec
     0:01- 1:00    0    0    0    0    0    0    0    0    0    0    0    0
     1:01- 2:00    0    0    0    0    0    0    0    0    0    0    0    0
     2:01- 3:00    0    0    0    0    0    0    0    0    0    0    0    0
     3:01- 4:00    0    0    0    0    0    0    0    0    0    0    0    0
     4:01- 5:00    0    0    0    0    0    1    0    0    0    0    0    0
     5:01- 6:00    0    0    0   25   47   87   51   22    1    0    0    0
     6:01- 7:00    0    2   38  194  201  283  200  162   85   64    0    0
     7:01- 8:00   50   98  210  340  345  413  310  304  239  279  168   63
     8:01- 9:00  220  246  309  407  439  509  444  466  365  383  297  266
     9:01-10:00  277  338  424  470  526  575  525  554  523  399  372  375
    10:01-11:00  288  449  477  456  561  599  617  594  653  438  428  413
    11:01-12:00  303  467  531  546  576  641  657  643  744  445  426  473
    12:01-13:00  342  498  537  504  572  653  705  666  732  533  360  455
    13:01-14:00  398  494  535  536  579  687  732  675  730  537  414  461
    14:01-15:00  326  487  481  494  553  659  712  678  688  478  314  403
    15:01-16:00  295  413  433  403  499  570  660  621  593  393  229  306
    16:01-17:00   37  273  348  363  395  499  584  488  447  186   73  101
    17:01-18:00    2   65  153  285  286  368  432  352  208   44    0    0
    18:01-19:00    0    0    8  100  107  186  222  103    9    0    0    0
    19:01-20:00    0    0    0    0    2   13   14    2    0    0    0    0
    20:01-21:00    0    0    0    0    0    0    0    0    0    0    0    0
    21:01-22:00    0    0    0    0    0    0    0    0    0    0    0    0
    22:01-23:00    0    0    0    0    0    0    0    0    0    0    0    0
    23:01-24:00    0    0    0    0    0    0    0    0    0    0    0    0
     Max Hour*  14   13   13   12   14   14   14   15   12   14   11*  12
     Min Hour     1    1    1    1    1    1    1    1    1    1    1    1

- Average Hourly Statistics for Diffuse Horizontal Solar Radiation Wh/m²
               JanFebMarAprMayJunJulAugSepOctNovDec
     0:01- 1:00    0    0    0    0    0    0    0    0    0    0    0    0
     1:01- 2:00    0    0    0    0    0    0    0    0    0    0    0    0
     2:01- 3:00    0    0    0    0    0    0    0    0    0    0    0    0
     3:01- 4:00    0    0    0    0    0    0    0    0    0    0    0    0
     4:01- 5:00    0    0    0    0    0    0    0    0    0    0    0    0
     5:01- 6:00    0    0    0    1   26   35   24   12    0    0    0    0
     6:01- 7:00    0    1   14   45   81   79   73   56   36    5    0    0
     7:01- 8:00    2   28   70  107  135  129  140  112   98   61   28   11
     8:01- 9:00   51   82  124  155  190  177  182  159  146  118   84   57
     9:01-10:00  105  123  169  225  215  192  199  196  181  155  127  100
    10:01-11:00  146  164  203  268  255  235  224  219  192  208  167  131
    11:01-12:00  174  187  227  267  260  232  242  225  189  226  192  141
    12:01-13:00  176  173  224  281  249  242  211  231  190  225  205  153
    13:01-14:00  170  178  227  258  244  221  205  207  178  191  178  134
    14:01-15:00  148  154  194  226  211  201  192  184  156  184  147   98
    15:01-16:00  122  118  159  216  188  190  167  154  134  144  114   67
    16:01-17:00   34   71  100  162  149  148  137  128   95   91   10   20
    17:01-18:00    0   24   49  126   93  109   96   81   46    3    0    0
    18:01-19:00    0    0    2    9   39   54   47   31    3    0    0    0
    19:01-20:00    0    0    0    0    0    5    9    1    0    0    0    0
    20:01-21:00    0    0    0    0    0    0    0    0    0    0    0    0
    21:01-22:00    0    0    0    0    0    0    0    0    0    0    0    0
    22:01-23:00    0    0    0    0    0    0    0    0    0    0    0    0
    23:01-24:00    0    0    0    0    0    0    0    0    0    0    0    0
     Max Hour*  13   12   14   13   12   13   12   13   11*  12   13   13
     Min Hour     1    1    1    1    1    1    1    1    1    1    1    1

- Average Hourly Statistics for Global Horizontal Solar Radiation Wh/m²
               JanFebMarAprMayJunJulAugSepOctNovDec
     0:01- 1:00    0    0    0    0    0    0    0    0    0    0    0    0
     1:01- 2:00    0    0    0    0    0    0    0    0    0    0    0    0
     2:01- 3:00    0    0    0    0    0    0    0    0    0    0    0    0
     3:01- 4:00    0    0    0    0    0    0    0    0    0    0    0    0
     4:01- 5:00    0    0    0    0    0    0    0    0    0    0    0    0
     5:01- 6:00    0    0    0    2   31   45   29   14    0    0    0    0
     6:01- 7:00    0    1   17   83  136  165  127   91   47    8    0    0
     7:01- 8:00    3   39  119  237  295  330  282  234  175  122   47   15
     8:01- 9:00   92  150  254  383  469  511  462  429  330  269  164  108
     9:01-10:00  197  268  414  558  625  650  607  600  520  368  277  222
    10:01-11:00  272  409  532  641  749  773  769  717  684  486  382  306
    11:01-12:00  326  473  626  746  800  845  863  805  790  531  425  367
    12:01-13:00  353  490  638  726  787  872  886  840  786  589  401  373
    13:01-14:00  365  476  619  708  763  855  879  797  735  528  381  336
    14:01-15:00  280  409  505  595  656  751  786  716  613  433  269  239
    15:01-16:00  206  281  381  463  523  594  634  560  445  292  170  135
    16:01-17:00   40  135  221  321  349  421  456  366  252  131   15   27
    17:01-18:00    0   30   73  196  184  244  254  187   80    4    0    0
    18:01-19:00    0    0    2   14   53   87   86   44    3    0    0    0
    19:01-20:00    0    0    0    0    0    5   11    1    0    0    0    0
    20:01-21:00    0    0    0    0    0    0    0    0    0    0    0    0
    21:01-22:00    0    0    0    0    0    0    0    0    0    0    0    0
    22:01-23:00    0    0    0    0    0    0    0    0    0    0    0    0
    23:01-24:00    0    0    0    0    0    0    0    0    0    0    0    0
     Max Hour    14   13   13   12   12   13   13   13   12   13   12   13
     Min Hour     1    1    1    1    1    1    1    1    1    1    1    1

- Average Hourly Statistics for Total Sky Cover %
               JanFebMarAprMayJunJulAugSepOctNovDec
     0:01- 1:00   59   43   54   47   43   28   37   41   42   31   49   42
     1:01- 2:00   60   46   60   53   41   26   41   40   51   33   45   40
     2:01- 3:00   62   52   59   48   43   27   45   41   55   30   46   43
     3:01- 4:00   60   55   61   52   42   31   50   38   59   30   46   44
     4:01- 5:00   63   57   65   56   50   40   52   45   65   33   49   43
     5:01- 6:00   62   61   60   53   54   37   55   52   64   39   54   38
     6:01- 7:00   60   63   59   59   55   36   58   54   63   41   55   38
     7:01- 8:00   61   67   63   51   51   34   52   54   62   42   52   43
     8:01- 9:00   65   68   64   48   48   32   45   42   59   44   49   50
     9:01-10:00   64   71   59   43   46   29   38   38   43   40   44   50
    10:01-11:00   63   66   54   42   45   30   32   35   33   37   46   52
    11:01-12:00   58   64   55   42   48   26   26   33   25   36   42   49
    12:01-13:00   52   59   53   43   46   27   19   30   25   35   39   50
    13:01-14:00   50   61   55   40   46   24   18   27   22   34   41   48
    14:01-15:00   49   62   62   39   44   24   17   27   20   31   43   44
    15:01-16:00   47   64   59   41   47   25   16   26   20   32   46   43
    16:01-17:00   47   62   56   43   48   27   19   31   21   27   46   44
    17:01-18:00   49   61   57   40   45   27   24   33   22   29   46   45
    18:01-19:00   47   59   51   40   43   29   27   36   18   26   46   42
    19:01-20:00   51   54   45   39   42   31   28   37   18   25   47   41
    20:01-21:00   53   49   47   41   39   30   27   38   19   27   44   42
    21:01-22:00   54   44   45   43   39   26   29   40   27   26   46   45
    22:01-23:00   58   43   46   40   38   30   32   38   32   27   44   44
    23:01-24:00   55   41   50   40   38   26   36   41   39   26   46   49
     Max Hour     9   10    5    7    7    5    7    7    5    9    7   11
     Min Hour    16   24   22   15   23   14   16   16   19   20   13    6

- Average Hourly Statistics for Opaque Sky Cover %
               JanFebMarAprMayJunJulAugSepOctNovDec
     0:01- 1:00   57   36   41   41   38   28   36   35   38   26   44   36
     1:01- 2:00   57   38   44   45   34   26   40   36   46   30   43   35
     2:01- 3:00   58   39   43   43   37   27   44   36   51   27   43   37
     3:01- 4:00   57   41   49   50   39   31   48   34   57   28   45   37
     4:01- 5:00   60   43   45   54   45   39   50   36   62   30   47   35
     5:01- 6:00   60   46   46   52   45   36   54   41   57   37   51   33
     6:01- 7:00   58   48   49   58   48   35   56   45   52   39   52   32
     7:01- 8:00   59   49   46   50   44   31   50   46   52   40   49   38
     8:01- 9:00   62   51   50   46   40   29   43   36   47   43   48   43
     9:01-10:00   61   53   43   41   37   26   37   32   34   38   43   44
    10:01-11:00   59   50   41   40   35   27   30   31   25   36   45   44
    11:01-12:00   55   46   35   40   35   22   25   26   16   34   38   41
    12:01-13:00   49   42   33   40   33   21   18   23   15   30   37   43
    13:01-14:00   46   41   34   38   34   18   15   20   13   30   36   40
    14:01-15:00   45   40   37   37   32   20   15   18   13   27   40   42
    15:01-16:00   44   39   37   39   33   22   13   19   14   29   42   39
    16:01-17:00   41   40   36   41   36   24   16   24   16   25   44   39
    17:01-18:00   46   39   38   38   34   24   21   22   16   27   42   40
    18:01-19:00   44   40   30   38   36   24   25   26   14   24   42   36
    19:01-20:00   45   37   27   36   36   27   26   29   14   23   42   36
    20:01-21:00   49   35   31   37   35   27   25   33   16   25   39   35
    21:01-22:00   49   32   32   40   35   25   27   36   22   23   41   38
    22:01-23:00   53   33   31   38   33   30   31   35   26   24   41   39
    23:01-24:00   52   33   35   38   31   26   35   36   33   23   43   43
     Max Hour     9   10    9    7    7    5    7    8    5    9    7   10
     Min Hour    17   22   20   20   24   14   16   15   14   20   14    7

The program calculated “undisturbed” ground temperatures:

- Monthly Calculated "undisturbed" Ground Temperatures** °C
               JanFebMarAprMayJunJulAugSepOctNovDec
       0.5 m    9.8  9.5 10.1 11.5 13.4 15.1 16.3 16.7 16.0 14.6 12.8 11.0
       2.0 m   11.0 10.4 10.6 11.4 12.6 14.0 15.1 15.7 15.6 14.8 13.5 12.1
       4.0 m   12.0 11.4 11.3 11.6 12.4 13.3 14.2 14.8 14.9 14.5 13.8 12.8

- **These ground temperatures should NOT BE USED in the GroundTemperatures object to compute building floor losses.
-   The temperatures for 0.5 m depth can be used for GroundTemperatures:Surface.
-   The temperatures for 4.0 m depth can be used for GroundTemperatures:Deep.
-   Calculations use a standard soil diffusivity of 2.3225760E-03 {m**2/day}

As noted in the above statistics calculation, the “undisturbed” ground temperatures calculated by the weather converter should not be used in building losses but are appropriate to be used in the GroundTemperatures:Surface and GroundTemperatures:Deep objects. The reasoning (for building losses) is that these values are too extreme for the soil under a conditioned building. For best results, use the Slab or Basement program described in this document to calculate custom monthly average ground temperatures (see the Ground Heat Transfer section). This is especially important for residential applications and very small buildings. If one of these ground temperature preprocessors is not used, for typical commercial buildings in the USA, a reasonable default value is 2C less than the average indoor space temperature.

Heating/cooling degree days from the weather file are shown. Long term heating/cooling degree days are shown earlier if available from ASHRAE HOF for the location/WMO.

- Monthly Heating/Cooling Degree Days/Hours
               JanFebMarAprMayJunJulAugSepOctNovDec
    HDD 10C   52    3    7    1    0    0    0    0    0    0    1   36
    HDD 18C  290  188  223  173  130  100   73   59   54   92  169  273

    CDD 10C   10   39   32   68  118  142  188  189  200  157   72   10
    CDD 18C    0    0    0    0    0    3   14    0   14    1    0    0

    CDH 20C    0    9    0   45   93  136  330  223  410  129    0    0
    CDH 23C    0    0    0    5   13   41  167   50  169   13    0    0
    CDH 27C    0    0    0    0    0    0   61    5   59    0    0    0

- 1227 annual cooling degree-days (10°C baseline)
-  100 annual heating degree-days (10°C baseline)

-   32 annual cooling degree-days (18°C baseline)
- 1825 annual heating degree-days (18°C baseline)

In the preceding display for degree-days, users more familiar with degree days to a Fahrenheit temperature base, may wish to multiply the degree day or degree hour values by 9/5.

And then the Köppen, ASHRAE and typical/extreme period calculations:

- Climate type "Cfb" (Köppen classification)**
- Marine west coastal (warm summer, mild winter, rain all year, lat. 35-60°N)
- **Note that the Köppen classification shown here is derived algorithmically from the source weather data.
-   It may not be indicative of the long term climate for this location.

- Climate type "3C" (ASHRAE Standards 90.1-2004 and 90.2-2004 Climate Zone)**
- Warm - Marine, Probable Köppen classification=Cs, Dry Summer Subtropical (Mediterranean)
- **Note that the ASHRAE classification shown here is derived algorithmically from the source weather data.
-   It may not be indicative of the long term climate for this location.

- Typical/Extreme Period Determination

- Summer is Jul:Sep
         Extreme Summer Week (nearest maximum temperature for summer)
         Extreme Hot Week Period selected: Sep 23:Sep 29, Maximum Temp=  35.10°C, Deviation=|16.393|°C
         Typical Summer Week (nearest average temperature for summer)
         Typical Week Period selected: Aug 19:Aug 25, Average Temp=  16.27°C, Deviation=| 0.032|°C

- Winter is Jan:Mar
         Extreme Winter Week (nearest minimum temperature for winter)
         Extreme Cold Week Period selected: Jan 22:Jan 28, Minimum Temp=  -0.40°C, Deviation=| 8.532|°C
         Typical Winter Week (nearest average temperature for winter)
         Typical Week Period selected: Mar  5:Mar 11, Average Temp=  10.19°C, Deviation=| 0.417|°C

- Autumn is Oct:Dec
         Typical Autumn Week (nearest average temperature for autumn)
         Typical Week Period selected: Nov 12:Nov 18, Average Temp=  12.19°C, Deviation=| 0.990|°C

- Spring is Apr:Jun
         Typical Spring Week (nearest average temperature for spring)
         Typical Week Period selected: May 13:May 19, Average Temp=  13.59°C, Deviation=| 0.018|°C

As this data is all tab-delimited, putting in a spreadsheet and displaying is not difficult:

And these can be easily used to produce graphs:

Design Day Calculations Output[LINK]

Using the WMO field (or determining it from the WBAN field), the Weather Converter performs table look up in the Design Condition files to see if there are recorded design conditions for the subject location. If this location is found, then design day objects are produced on the resultant design day object (ddy extension) file - ready for inclusion into an EnergyPlus input data file. If no design conditions are located, then the design day object file will still include a location object for inclusion with EnergyPlus. However, statistics using the weather file are displayed to the statistics file - these “can” be used to create your own design day definitions but you should read the warning that is issued and take care if your weather file is only a “single instance” weather data representation.

The location objects as well as the design condition objects are constrained by the data source. Some data sources do not have elevation information - thus, a location object from such a source will have an elevation of 0.0. Likewise, the time zone of some locations may not be available from the source data nor other data resources that the weather converter uses. A time zone will be estimated from the standard meridian of the location (determined by the longitude) but it may not be accurate. A user needs to be aware of these limitations when taking the design day files from the weather converter.

Note that you can always include a “def” file with this data to assure accuracy regardless of input format limitations.

An excerpt of a design day output is shown in the following (actual design day objects have been deleted for brevity). Note that with the 2009 ASHRAE HOF climate conditions, a possible DaylightSavingPeriod object may be included.

! The following Location and Design Day data are produced as possible from the indicated data source.
 ! Wind Speeds follow the indicated design conditions rather than traditional values (6.7 m/s heating, 3.35 m/s cooling)
 ! No special attempts at re-creating or determining missing data parts (e.g. Wind speed or direction)
 ! are done.  Therefore, you should look at the data and fill in any incorrect values as you desire.

 Site:Location,
  Chicago Ohare Intl Ap_IL_USA Design_Conditions,     !- Location Name
      41.98,     !- Latitude {N+ S-}
     -87.92,     !- Longitude {W- E+}
      -6.00,     !- Time Zone Relative to GMT {GMT+/-}
     201.00;     !- Elevation {m}

 !  WMO=725300 Time Zone=NAC: (GMT-06:00) Central Time (US & Canada)
 !  Data Source=ASHRAE 2009 Annual Design Conditions
 RunPeriodControl:DaylightSavingTime,
   2nd Sunday in March,    !- StartDate
   2nd Sunday in November;    !- EndDate

! Using Design Conditions from "Climate Design Data 2009 ASHRAE Handbook"
 ! Chicago Ohare Intl Ap_IL_USA Extreme Annual Wind Speeds, 1%=11.1m/s, 2.5%=9.4m/s, 5%=8.6m/s
 ! Chicago Ohare Intl Ap_IL_USA Extreme Annual Temperatures, Max Drybulb=-23.7°C Min Drybulb=35.9°C

 ! Chicago Ohare Intl Ap_IL_USA Annual Heating Design Conditions Wind Speed=4.9m/s Wind Dir=270
 ! Chicago Ohare Intl Ap Annual Cooling Design Conditions Wind Speed=5.2m/s Wind Dir=230

 ! Coldest Month=January
 ! Chicago Ohare Intl Ap IL USA Annual Heating 99.6%, MaxDB=-20°C

 ! Chicago Ohare Intl Ap IL USA Annual Heating 99%, MaxDB=-16.6°C

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (DB=>MWB) 1%, MaxDB=31.6°C MWB=23°C

 ! Chicago Ohare Intl Ap IL USA Annual Humidification 99.6% Design Conditions DP=>MCDB, DP=-25.7°C

 ! Chicago Ohare Intl Ap IL USA Annual Humidification 99% Design Conditions DP=>MCDB, DP=-22.1°C

 ! Chicago Ohare Intl Ap IL USA Annual Heating Wind 99.6% Design Conditions WS=>MCDB, WS=12.4m/s

 ! Chicago Ohare Intl Ap IL USA Annual Heating Wind 99% Design Conditions WS=>MCDB, WS=11.4m/s

! Hottest Month=July
 ! Chicago Ohare Intl Ap IL USA Annual Cooling (DB=>MWB) .4%, MaxDB=33.3°C MWB=23.7°C

 ! Chicago Ohare Intl Ap IL USA Annual Heating Design Conditions Wind Speed=4.9m/s Wind Dir=270

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (DB=>MWB) 2%, MaxDB=30.1°C MWB=22.1°C

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (WB=>MDB) .4%, MDB=31.2°C WB=25.5°C

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (WB=>MDB) 1%, MDB=29.6°C WB=24.5°C

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (WB=>MDB) 2%, MDB=28.1°C WB=23.5°C

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (DP=>MDB) .4%, MDB=28.9°C DP=23.8°C HR=0.0192

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (DP=>MDB) 1%, MDB=27.7°C DP=22.9°C HR=0.0180

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (DP=>MDB) 2%, MDB=26.5°C DP=21.9°C HR=0.0170

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (Enthalpy=>MDB) .4%, MDB=31.4°C Enthalpy=79.2kJ/kg

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (Enthalpy=>MDB) 1%, MDB=29.6°C Enthalpy=75.1kJ/kg

 ! Chicago Ohare Intl Ap IL USA Annual Cooling (Enthalpy=>MDB) 2%, MDB=28.2°C Enthalpy=70.9kJ/kg

Design day “definitions” originate in the ASHRAE Handbook of Fundamentals. Prior to 1997, these conditions were described for winter and summer (heating and cooling). They were based on seasonal percentages.

EnergyPlus uses the design day object values and creates an entire day of weather data - this is described more fully in the Input Output Reference under the DesignDay object. The weather converter program assigns “SummerDesignDay” and “WinterDesignDay” day types by default - these day types influence “scheduling” of various elements. How to use these effectively is described during the DesignDay and Schedule objects discussions in the Input Output Reference.

Beginning in 1997, and continuing (the latest version was published in 2009), the design condition data is based on annual percentages. In addition, only locations with long-term hourly observations data (on which to form the basis) are included.

[From ASHRAE Handbook of Fundamentals, 2009]:[LINK]

• Design data based on dry-bulb temperature represent peak occurrences of the sensible component of ambient outdoor conditions. Design values based on wet-bulb temperature are related to the enthalpy of the outdoor air. Conditions based on dew point relate to the peaks of the humidity ratio. The designer, engineer, or other user must decide which set(s) of conditions and probability of occurrence apply to the design situation under consideration.
• The 99.6% and 99% Heating conditions are often used in the sizing of heating equipment.
• The 0.4, 1.0, and 2.0% dry-bulb temperatures and mean coincident wet-bulb temperatures (i.e., DB=>MWB) often represent conditions on hot, mostly sunny days. These are often used in sizing cooling equipment such as chillers or air-conditioning units.
• Design conditions based on wet-bulb temperatures (i.e., WB=>MDB) represent extremes of the total sensible plus latent heat of outdoor air. This information is useful for cooling towers, evaporative coolers, and fresh air ventilation system design.
• Design conditions based on dew-point temperatures (i.e., DP=>MDB) are directly related to extremes of humidity ratio, which represent peak moisture loads from the weather. Extreme dew-point conditions may occur on days with moderate dry-bulb temperatures, resulting in high relative humidity. These values are especially useful for humidity control applications, such as desiccant cooling and dehumidification, cooling-based dehumidification, and fresh-air ventilation systems. The values are also used as a check point when analyzing the behavior of cooling systems at part-load conditions, particularly when such systems are used for humidity control as a secondary function. Humidity ratio values are calculated from the corresponding dew-point temperature and the standard pressure at the location’s elevation.
• The enthalpy design conditions (i.e. Enthalpy => MDB) gives the annual enthalpy for the cooling season; this is used for calculating cooling loads caused by infiltration and/or ventilation into buildings. Enthalpy represents the total heat content of air (the sum of its sensible and latent energies). Cooling loads can be easily calculated knowing the conditions of both the outdoor ambient and the building’s interior air.