Sky luminance measurements for design and control of indoor daylight illumination

Abstract

Cost-effective daylighting design and artificial lighting control require data on the daylight illuminance at the work station. The current definition of the daylight factor is not appropriate to convert accurately from the horizontal illuminance under an unobstructed sky to the actual illuminance in a room. The actual daylight illuminance of a room is found to be related to the actual luminance pattern of the sky in the direction of view of the window. To represent conveniently both the dynamic character of the sky luminance and the weight of the luminance patches in respect of the indoor illuminance, the dynamic equivalent luminance is introduced. Some progress has been made in predicting the indoor direct illuminance due to time-varying sky luminance patterns more accurately.

Get full access to this article

View all access options for this article.

References

International Lighting Vocabulary CIE Publication 17 (Paris: Commission Internationale de l'Eclairage ) (1970)

Tregenza P.R.

The daylight factor and actual illuminance ratios

Lighting Res. Technol. 12(2) 64-68 (1980)

Hunt D R G

Predicting artificial lighting use—a method based upon observed patterns of behaviour

Lighting Res. Technol. 12(1) 7-17( 1980)

Littlefair P.J.

Daylight availability for lighting controls

Proc. CIBS National Lighting Conf. Cambridge , 1984 pp 215-233 (1984)

Nakamura H. and Oki M.

Calculation of daylight factor dominated by intermediate sky

General Proc. Int. Daylighting Conf. Phoenix, 1983 pp 57-59 (1983)

Littlefair P.J.

The luminance distribution of an average sky

Lighting Res. Technol. 13(4) 192-198 (1981)

Tregenza P.R. and Waters I.M.

Predicting daylight from cloudy skies

Energy and Buildings 6 261-266 (1984 )

Tregenza P.R.

Cloud cover and daylight illuminance

Building and Environment 22(3) 163-165 (1987)

Tregenza P.R.

Measured and calculated frequency distributions of daylight illuminance

Lighting Res. Technol. 18(2) 71-74 (1986)

10.

Navvab M. , Love J. and Ne'eman E.

Daylight and solar availability data for Ann Arbor, Michigan

USA Proc. Symp. Daylight and Solar Radiation Measurement, Berlin 1989 pp 61-69 (1989)

11.

Rutten A J F

Towards new daylighting design data (in Dutch)

I2-Bouwkunde en Civiele Techniek 4(3) 13-16 (1988)

12.

Rutten A J F

Daylighting design and luminance measurements of the sky vault

Proc. VI Lux Europa Conf. Budapest Vol. 1 pp 313-320 (1989)

13.

Zonneveldt L. and Rutten A J F Daylight availability in the Netherlands (in Dutch) (Eindhoven: Institute of Applied Physics) TNO-TUE-FAGO no. 618.011 (1988)