Re: [EnergyPlus_Support] example getting starting

The percentages in the example files are from the design conditions in the ASHRAE 2009 Fundamentals. 4% DB cooling conditions means that on an annual basis, you could expect the temperatures will be higher than that temperature 4% of the year (or 350 hours out of 8760). It is engineering judgment how many hours (percent) you are willing for the temperature to exceed the design conditions (typical . Similarly 99.6% heating conditions means that 99.6% of the annual hours you can expect the temperature will be above the design temperature (or 35 hours out of 8760 per year). DB ==> MWB means the percentiles are for dry-bulb temperature, the wet-bulb is calculated as a mean for hours that have that DB temperature.

For many of the weather files (at least those that have design data in the 2009 Fundamentals), there are design conditions in the weather files. If you would like to see what those various design conditions are, look at the .STAT file that accompanies the file in the .zip when you download from the web site. Alternately you can run the .EPW through the Weather Statistics and Conversion utitilty. It will create a .DDY file with the design conditions in IDF-ready format for that location. For example, the .DDY for USA_IL_Chicago looks like (just a subset of the 17 heating and cooling design conditions including dry-bulb, wet-bulb, wind speed, etc.):

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,
   1st Sunday in April,    !- StartDate
   Last Sunday in October;    !- 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
! Coldest Month=JAN
! Chicago Ohare Intl Ap_IL_USA Annual Heating 99.6%, MaxDB=-20°C
SizingPeriod:DesignDay,
Chicago Ohare Intl Ap Ann Htg 99.6% Condns DB,     !- Name
        -20,      !- Maximum Dry-Bulb Temperature {C}
        0.0,      !- Daily Temp Range {C}
        -20,      !- Humidity Indicating Conditions at Maximum Dry-Bulb
     98934.,      !- Barometric Pressure {Pa}
        4.9,      !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph)
        270,      !- 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
          1,      !- Month
WinterDesignDay,!- Day Type
          0,      !- Daylight Savings Time Indicator
   WetBulb;       !- Humidity Indicating Type

! Chicago Ohare Intl Ap Annual Cooling Design Conditions Wind Speed=5.2m/s Wind Dir=230
! Hottest Month=JUL
! Chicago Ohare Intl Ap_IL_USA Annual Cooling (DB=>MWB) .4%, MaxDB=33.3°C MWB=23.7°C
SizingPeriod:DesignDay,
Chicago Ohare Intl Ap Ann Clg .4% Condns DB=>MWB,     !- Name
       33.3,      !- Maximum Dry-Bulb Temperature {C}
       10.5,      !- Daily Temp Range {C}
       23.7,      !- Humidity Indicating Conditions at Maximum Dry-Bulb
     98934.,      !- Barometric Pressure {Pa}
        5.2,      !- Wind Speed {m/s} design conditions vs. traditional 3.35 m/s (7mph)
        230,      !- Wind Direction {Degrees; N=0, S=180}
       1.00,      !- Clearness {0.0 to 1.1}
          0,      !- Rain {0-no,1-yes}
          0,      !- Snow on ground {0-no,1-yes}
         21,      !- Day of Month
          7,      !- Month
SummerDesignDay,!- Day Type
          0,      !- Daylight Savings Time Indicator
   WetBulb;       !- Humidity Indicating Type