The daylight factors report contains the pre-calculated
hourly daylight factors for the four CIE sky types (clear,
clear turbid, intermediate, and overcast sky), for each
daylight reference points for each exterior window of a
daylight enclosure which consists of one or more spaces. The
file is CSV formatted – ready for spreadsheet viewing. The
input for requesting the report is simple:
Output:DaylightFactors,
SizingDays; !- Reporting Days
The following shows an excerpt the daylight factors for a
window without shade:
This file contains daylight factors for all exterior windows of daylight zones.
MonthAndDay,Enclosure Name, Zone Name,Window Name,Window State
Hour,Reference Point,Daylight Factor for Clear Sky,Daylight Factor for Clear Turbid Sky,Daylight Factor for Intermediate Sky,Daylight Factor for Overcast Sky
01/21,Enclosure 1,ZN_1,ZN_1_WALL_NORTH_WINDOW,Base Window
1,ZN_1_DAYLREFPT1,0.00000,0.00000,0.00000,0.00000
1,ZN_1_DAYLREFPT2,0.00000,0.00000,0.00000,0.00000
1,ZN_1_DAYLREFPT3,0.00000,0.00000,0.00000,0.00000
[...]
9,ZN_1_DAYLREFPT1,2.14657E-002,1.73681E-002,1.38241E-002,1.41272E-002
9,ZN_1_DAYLREFPT2,2.14657E-002,1.73680E-002,1.38240E-002,1.41273E-002
9,ZN_1_DAYLREFPT3,2.14655E-002,1.73678E-002,1.38239E-002,1.41274E-002
[...]
24,ZN_1_DAYLREFPT1,0.00000,0.00000,0.00000,0.00000
24,ZN_1_DAYLREFPT2,0.00000,0.00000,0.00000,0.00000
24,ZN_1_DAYLREFPT3,0.00000,0.00000,0.00000,0.00000
The first line describes the data in the
eplusout.dfs file.
The second line describes the header of the daily row:
| MonthAndDay |
Zone Name |
Window Name |
Window State |
| 01/21 |
ZN_1 |
ZN_1_WALL_NORTH_WINDOW |
Base Window |
The Window
State column has three possible outputs – “Base Window”
indicating windows without shades; a numeric value, from 0.0
to 180.0 for every 10.0 step, indicating the slat angle (in
degrees) of the blind shading the window; “Blind or Slat
Applied” indicating windows in shaded state by shades,
screens, and blinds with fixed slat angle.
The lines after it describes the hourly daylight factors at
each reference point:
Hourly Daylight Factors for the considered window at
each reference point and 4 CIE Sky Conditions
| Hour |
Reference Point |
Daylight Factor for Clear
Sky |
Daylight Factor for Clear Turbid
Sky |
Daylight Factor for Intermediate
Sky |
Daylight Factor for Overcast
Sky |
| 9 |
ZN_1_DAYLREFPT1 |
0.021466 |
0.017368 |
0.013824 |
0.014127 |
| 9 |
ZN_1_DAYLREFPT2 |
0.021466 |
0.017368 |
0.013824 |
0.014127 |
| 9 |
ZN_1_DAYLREFPT3 |
0.021465 |
0.017368 |
0.013824 |
0.014127 |
| 10 |
ZN_1_DAYLREFPT1 |
0.020245 |
0.016029 |
0.012201 |
0.014127 |
eplusout.dfs[LINK]
The daylight factors report contains the pre-calculated hourly daylight factors for the four CIE sky types (clear, clear turbid, intermediate, and overcast sky), for each daylight reference points for each exterior window of a daylight enclosure which consists of one or more spaces. The file is CSV formatted – ready for spreadsheet viewing. The input for requesting the report is simple:
The following shows an excerpt the daylight factors for a window without shade:
The first line describes the data in the eplusout.dfs file.
The second line describes the header of the daily row:
The Window State column has three possible outputs – “Base Window” indicating windows without shades; a numeric value, from 0.0 to 180.0 for every 10.0 step, indicating the slat angle (in degrees) of the blind shading the window; “Blind or Slat Applied” indicating windows in shaded state by shades, screens, and blinds with fixed slat angle.
The lines after it describes the hourly daylight factors at each reference point:
Documentation content copyright © 1996-2026 The Board of Trustees of the University of Illinois and the Regents of the University of California through the Ernest Orlando Lawrence Berkeley National Laboratory. All rights reserved. EnergyPlus is a trademark of the US Department of Energy.
This documentation is made available under the EnergyPlus Open Source License v1.0.