Discrepancy between the simulated DF and calculated DF in Desktop RADIANCE 2.0.

Dear All,

I am using Desktop RADIANCE 2.0 with AutoCAD R14.

For the DF, I got different values from the simulated (from the
simulation manager) and calculated DF (from the illuminance ratio of
indoor/outdoor sensor). I don’t know which one is correct DF. I
also measured with scale model to compare the DF with DR simulation.
DF in scale model is very close to the simulated DF (from the
simulation manager option). Calculated DF from indoor/outdoor
illuminance is higher than simulated DF.

By checking the batch files in project folder, I noticed the
difference between the simulated DF and calculated DF is come from
the outdoor illuminance level. But I could not figure out why I got
different numbers.

As shown below, all the numbers are same in batch files.
In the FL_0110.bat file, 26100 looks like outdoor illuminance (see
the FL_0110.bat file).
However, outdoor illuminance at that time is 14648.064 lx (see the
Out_0110_I_out.out file).

Outdoor illuminance level in DF simulation is higher than
illuminance simulation for outdoor sensor. I think the difference of
DF is come from the difference of outdoor illuminance level. But I
still can not understand which one is correct.

*I run all the simulation at the same conditions. All runs are at
1:10 pm (CST) in College Station. And all the other parameters are
also same.

···

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Batch Files in Project Folder

Run for DF calculation (FL_0110.bat)

del FL_0110_DF_floor.out
rad -v 0 FL_0110.rif
type Grid_floor.pts | rtrace @FL_0110.opt -faa -h -opv -I -dv- -x 1
FL_01101.oct | rcalc -e '$1=$1;$2=$2;$3=$3;$4=
($4*47.4482686+$5*119.950519+$6*11.6012125)/26100.000000' >>
FL_0110_DF_floor.out
@cls

Run for Indoor Illuminance (FL_Illum_0110.bat)

del FL_Illum_0110_I_floor.out
rad -v 0 FL_Illum_0110.rif
type Grid_floor.pts | rtrace @FL_Illum_0110.opt -faa -h -opv -I -dv-
-x 1 FL_Illum_01101.oct | rcalc -
e '$1=$1;$2=$2;$3=$3;$4=$4*47.4482686+$5*119.950519+$6*11.6012125'

FL_Illum_0110_I_floor.out

@cls

Run for Illuminance of Outdoor Sensor (Out_0110.bat)

del Out_0110_I_out.out
rad -v 0 Out_0110.rif
type Point_out.pts | rtrace @Out_0110.opt -faa -h -opv -I -dv- -x 1
Out_01101.oct | rcalc -
e '$1=$1;$2=$2;$3=$3;$4=$4*47.4482686+$5*119.950519+$6*11.6012125'

Out_0110_I_out.out

@cls

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Out Files in Project Folder

Run for DF calculation (FL_0110_DF_floor.out)

3750 4800 275.0001 0.00196749261
7500 4800 275.0001 0.00202036887
11250 4800 275.0001 0.00186442329
3750 3300 275.0001 0.0020485585 Floor_1
7500 3300 275.0001 0.00214985753 Floor_2
11250 3300 275.0001 0.00199673954 Floor_3
3750 1800 275.0001 0.00195969207
7500 1800 275.0001 0.00215063028
11250 1800 275.0001 0.00186199776

Run for Indoor Illuminance (FL_Illum_0110_I_floor.out)

3750 4800 275.0001 52.3787953
7500 4800 275.0001 58.7716727
11250 4800 275.0001 50.8646398
3750 3300 275.0001 53.6415735 Floor_1
7500 3300 275.0001 55.2004445 Floor_2
11250 3300 275.0001 54.263763 Floor_3
3750 1800 275.0001 53.1193063
7500 1800 275.0001 55.2840016
11250 1800 275.0001 52.6013467

Run for Illuminance of Outdoor Sensor (Out_0110_I_out.out)

14250 2900 14120 14648.064

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Thank you in advance.

Regards,
Byoungsoo Ahn.