Estimate Daylight Factor

Estimate the DF of a side-lit room from its geometry; then compute DAo and DAo.con from that DF.

Geometry

Window size

40 %

Room width

3.0 m

Room depth

4.0 m

Visible sky field

90°

Mean reflectance

60 %

Transmittance τ

Fixed parameters: room height 3 m, work plane 0.6 m, central and lateral (1 m) axes, transverse Gaussian blend, CIE overcast sky.

Room cross-section

From DF to DAo

Compatible data stays prepared automatically. Use the switcher above to calculate DAo without entering it again.

68.3%

DAo

81.7%

DAo.con

Plan (false colour)

Façade

Depth

0Width2.4 m

DF 0

17.8 %

Results

Central DF · front

20.1%

Central DF · back

1.8%

Lateral DF · back

1.7%

Mean DF

5.8%

Min

1.7%

Max

17.8%

Median

4.4%

P10

2.0%

P90

12.0%

Uniformity

0.29

Area ≥ 2%

88%

Area ≥ 3%

66%

Components (minimum point)OK

SC 0.57% · reflected 1.10% (66% of DF) at the minimum point. Means: SC 4.07% · reflected 1.69%.

Traceability & validation

8/8 tests passed

Window sizemeasured

Sky fieldmeasured

Depthmixed

Transverse distributionextrapolated

Reflectancereference

Transmittancereference

Sky componentmeasured

Room widthmeasured