Estimation of outdoor illuminance for passive solar architecture in Malaysia

Illuminance and daylight availability are important parametersin daylighting design for passive, low energy architecture. In Malaysia, the only climatic parameter that can be used for determining daylight availability is global solar irradiation, which is measured at major meteorologicalstations around the country. However, it is possible to estimate the global illuminance from global solar irradiation data if the global luminous efficacy is known.