A study on the impact of applications creating daylight effect in non-daylighted indoor spaces on user perception

Today, the growing increase in the non daylighted spaces resulted in some negative psychological and physiological effects on people who live in non daylighted rooms for long periods. This situation has encouraged new technologies in lighting area in order to prevent these negative effects in such indoor spaces. This thesis' aim is to light up the next researchs that will search for the new lighting systems in order to prevent the negative effects of being in non-daylighted indoor spaces. In the first chapter of the thesis; the subject, the aim and the method of the thesis are explained to show general approach of other chapters. In time the purpose of space is changed because of the changes of people's needs and expectations from a space. A space exists by intimately relation with other spaces this is why it is hard to identify the boundaries of a space. The change on the space structure and perception shows that the space is not a physical object that is detected by only senses, but also a perceptional image that appears by interpreting of sensorial data. On the creation of perceptional image, the sensorial data and the knowledge and experience as person and society are effective. In the second chapter of the thesis, space perception and the relation between light and the objects that created space are evaluated. Visual perception is the main subject on the space perception. The quantitative properties of the space such as form, material and color, create the visual values of the space. The interaction between these quantitative properties of the space and light adds perceptional value or causes the perceptional changing at the space. Perception stability and perception illusion are two main visual perception methods that are used to provide these perceptional changings. The spatial perceptional changings provided by lighting are dealt with in direction of the relation between light and quantitative properties of the space. On the other hand, the effects of the subjects that appear through the relation between space and light such as visual comfort and its components on the visual perception are analyzed. Lighting has a main role on the formation of space. In a link with this statement, different lighting arrangements have different effects on the space and also have different perceptions on users. In the third chapter, natural light and artificial light definitions are examined and the effects of natural light on the visual perception and human's psychological and physiological health are revealed. The main characteristic property of daylight is to be dynamic, changes according to season, daytime and place on earth. On the other hand, the visual effect on spaces and also the mood is always changing by daylight usage in the spaces, but also it can cause visual comfortless. To prevent this comfortless, daylight entrance should be under control by proper architectural elements or systems. Behind this, daylight is really powerful on the signification of the space, therefore daylight can be used as a symbolic element to add different significations to the space. Presence of daylight arranges the physiological changes such as sleep, hunger, body temperature and hormone production by providing the loop at circadian rhythm. On the other hand, psychological disorders that is observed in poor daylight or daylight absence situations, causes depression. Sunlight prevent from poor bone development and elder people's bone fragility risk that are coming from the lack of D vitamin, this is why people should be in touch with daylight by protected from the dangerous rays causes cancer. It is impossible to evaluate the systems provide daylight effect, without knowledge of daylight effects in the space and the daylight entrance types. Therefore in the third chapter, the methods of daylight entrance by vertical and horizontal openings are initiated. The sample projects that have daylight entrance are analized based on architectural details and spatial perception in chapter four. Behind this, the systems that give daylight effect in the space are analyzed based on the same subjects to present the successful and unsuccessful sides. In the fifth chapter, experimental study is prepared by using survey method. This study is applied on two different rooms; lighted by artificial light that has daylight effect and lighted by artificial light as recessed luminaires on the ceiling. These lighting systems are compared and evaluated in terms of visual comfort and perceptional effects on the users by analyzing the participants' answers to the applied survey. In the final chapter, the survey results and the general information given in previous chapters are evaluated and discussed. As a result, it is explained that further researches should be done basing on the results of this thesis in order to predict the user perception in non-daylighted indoor spaces more precisely.