IMPACT OF NATURAL LIGHT PENETRATION ON OCCUPANTS IN UNDERGROUND SPACE: AN FIELD QUASI-EXPERIMENT STUDY

Abstract

Due to the architectural constraints, underground spaces lack sufficient natural light, which is detrimental to the physiological and psychological health of the long-term occupants. To explore the effects of different proportion of natural light intervention on the work performance in underground spaces, the current study adopted a quasi-experimental method in the field and selected three underground spaces (Jinan West Railway Station, Olympic Sports Center Station, and Yinli INCITY) with different proportion of natural light intervention in Jinan as the experimental sites. The data of work mood, work state and work efficiency of 12 subjects under different times (daytime and nighttime) and different spaces (with/without natural light intervention) were collected. The degree of impact on work performance was quantified by results of differences-in-differences (DID). The results showed that, in general, the results showed that the higher proportion of natural light brought greater benefit to people worked in underground space. In the process of increasing the natural light penetration of underground space, the depression of occupants was relieved, and concentration was improved firstly. Then the confusion of occupants was reduced, and productivity was increased. The conclusion can provide a reference for the optimization design of light environment in underground spaces.