Lighting in the interior plays a huge role – it not only fills the darkest corners with light, but also creates the desired atmosphere, emphasizes style and places accents correctly.
In interior design, it plays a functional and aesthetic role. Designers use three basic schemes at the same time: general, work lighting and directional. General one is needed to move in the interior and normal activities. Among all the three schemes, it implies a minimum level of illumination and the widest luminous flux. Working one is used for special types of work that require intensive light flux, for example, during long-term reading or fine manual operations. Finally, directional one is usually used for aesthetic reasons to highlight elements of the interior – a fireplace, statues, or paintings on the wall. It is also used in retail, where it is necessary to draw attention to an object in the general product display.
The integral scheme of the general, working and directional light determines the selection of sources and the interior lighting solution. The source can be both natural and artificial; but it is always recommended to make the most of the daytime natural light. Plants and offices often even save by using natural one. When for some reason there is not enough natural light, designers use artificial sources, which are divided into incandescent, fluorescent, gas-discharge, and recently introduced LEDs. In everyday life most often incandescent bulbs, giving a warm, easily adjustable in intensity from appliances, the purchase and installation of which are relatively cheap are used. Traditional incandescent bulbs provide a fairly high level of luminous flux per watt, although newer halogen bulbs are significantly higher in this indicator. Fluorescent lighting is particularly advantageous when it is necessary to provide general light over a large area or when it is important to achieve a high level of luminous flux at low energy costs. However, fluorescent lamps are not very attractive because of their “cold” spectrum and the tubular shape of the lamps. Gas discharge lamps are used primarily for street lighting, in industrial or very large public buildings. They are very economical, providing ten times more powerful luminous flux per unit of power compared to incandescent lamps. This type is especially appropriate when using light reflected from high ceilings to illuminate large areas.
The nature of fixtures is largely predetermined by the type of light source itself. If incandescent bulbs are embedded in a variety of types of luminaires, then fluorescent sources assume mainly elongated or circular shapes. The choice of electrical fixtures also depends on whether the designer wants to make the elements into the artistic composition of the room or seeks to make them hidden. Fixtures are built into the floor and ceiling, they are covered behind bars or blinds, hung on a wall or ceiling, or finally hung from the ceiling like a chandelier. They are portable, placed on the floor or elevated above the floor surfaces. The placement of the lamps largely determines the overall atmosphere of the room. The light emanating from above, the ceiling level, is sharper, open, while the one at eye level gives the interiors a softer character. It at floor level increases safety of movement and adds dynamism to the room.