אדריכלות ישראלית - גיליון 123

Light - Functional Aesthetics אדריכלותישראלית Architecture of Israel # 123 November 2020 22 | | One of the best ways to determine good architecture is to evaluate how natural light is handled throughout the space it illuminates. Bob Borson The assumption that architecture constitutes the subsequent product of an encounter between need, location and time, indicates that natural light plays a central role in the design. This, due to the fact that light quality differs from one place to another according to geographical location, seasons of the year and hours of the day. Contrary to functional engineering, architecture deals with different facets of structure, over and above its functional aspects. The most common mistake is to overlook the difference between them, particularly between aesthetic effects of light and its functional essence. Thus, an impressive photograph might emphasize the aesthetic effect of shining light rays that penetrate a building in Africa as it would a building in London, although their functional essence is completely different and often completely contradictory. Consequently, many studies focus on natural light’s contribution to a space, overlooking its physio-psychological effects, such as blinding, over-heating, uneven distribution and uncontrolled focus. In this reality, most "amazing" photographs related to light usually show a window that floods the space with shining sun- rays, creating dramatic effects, while actually, there might be a glare problem (in a computer work space for instance) or over-heating, which might be problematic for attaining thermal comfort and, consequently, poor space functioning. Natural light is the elixir of life in general and architecture in particular. This is why any discrepancy between aesthetic and functional essence of light is important. This can be achieved by adjusting the proper solution to any situation, such as food for work aesthetic & functional aspects of natural light & artificial lighting Dr. Ami Ran double-glazed windows, skylights, light chimneys, mirrors, and anti UV light shelves that filter sun rays while allowing the penetration of filtered light (see extensive article in AI #122). The significance attributed to light sources and the fact that natural light has both functional, aesthetic and psychological traits, has over the years constituted a cardinal basis for developing architecture’s various stylistic codes. Thus, for instance, while a description of a building’s qualities through light that emphasizes its openings was characteristic of Modernist Style, in the Baroque era this was accomplished by emphasizing colors and formal mannerisms. Interestingly, since dramatic effects are achieved mainly through direct sunlight, clean, filtered northern light, is functionally much more important when evenly distributed through space. This finds expression is the sawtooth factory roofs where the windows were facing north. All of which took place prior to the invention of air-conditioning, which actually caused the loss of traditional architectural thinking. While, at the time, natural light penetration was achieved by basic shading devices, proper orientation and the windows’ position, today openings are installed in a building primarily on an aesthetic basis in order to facilitate attractive graphic compositions. Obviously light has a emotional effect. It is known that light symbolizes optimism (from which derives the cliché "the light at the end of the tunnel"). Hence, in this context "Master of Light" - Louis Kahn, referred to the light in his buildings as a poetic expression, focusing on how light is experienced and the user’s emotional response. For this, he brilliantly maneuvered the relationship between natural light and artificial lighting. In fact, natural light is what motivates all living organisms’ biological clock, expressing the difference between day and night, determining the metabolic cycle that regulates heart rate and liver function, which directly affects physical health and mood. In this light, every attempt to influence pace of life through artificial lighting has a physio-psychological effect that must be taken into account when planning artificial lighting to augment the intensity of natural light. A state of the art feature in this field is smart glass that automatically regulates required light compensation via artificial lighting according to the intensity of natural light, during the day and the seasons. Most popular contemporary technologies for light compensation are LED based (light-emitting diode) which has recently replaced the fluorescent. Such smart mechanisms are based on compensating sensor light deficiency, very much like a camera that compensates the required light intensity via exposure or shutter opening according to need. There are several developments in this field – the cheapest is the film coating of regular glass. Such devices are also used to obstruct sunlight via darkening that occurs when low voltage shifts ions from one side of the glass to the other, until the transparency of the glass is eliminated. Accordingly, smart systems categorically differentiate between white, "cold" light simulating daylight, and yellow, "warm" light that is usually meant to generate an atmosphere, by highlighting details to achieve the desired response. Such as intimacy, relaxation, excitement or spatial depth. Within this context, LED bulbs can today light up autonomously when natural light diminishes (street lighting for instance); other bulbs charged by natural light switch on when the intensity of natural light lessens, and some bulbs change color according to changing electrical voltage, infusing the environment with a dynamic or artistic effect (illumination of bridges or environmental sculptures).