Low work efficiency? Maybe it's because the office illuminance is not strong!
"Why shouldn't the office use warm light", because warm light gives people a sense of warmth, and prolonged exposure to this kind of light can easily make people sleepy and reduce work efficiency. The bright and cool light helps to concentrate and improve work efficiency. But if you want to improve work efficiency by changing the light environment in the office, it is not enough to change the light color alone, but also to consider the illuminance.
The meaning of illuminance
Illuminance, a term often used in interior lighting design, refers to the degree to which an object is illuminated. It is expressed by the luminous flux received per unit area, and the unit is "Lux" (Lux, lx). It is called lumen in the UK and Lux in Europe. Specifically, 1Lux is equal to the amount of light projected by a candle on a surface of one square meter from 1 meter away. 10 Lux is equal to the amount of light projected by 10 candles onto the surface of an object from 1 meter away. The illuminance is based on the luminous flux received by the vertical plane as the standard, and the illuminance will decrease if it is irradiated obliquely.
The "office illuminance" mentioned here refers to the brightness of the office lighting.
A space with high illuminance and low color temperature can make people feel sultry, while a space with low illuminance and high color temperature can make people feel gloomy and tired. Working in an environment with high color temperature but low illuminance, people tend to feel gloomy and tired, reducing work efficiency.
So how should the illuminance of the office be improved more scientifically? Let's first talk about what factors are related to the level of illuminance.
What does the spatial illuminance have to do with?
Generally for the same light source, the farther the light source is from the illuminated surface, the smaller the illuminance on the illuminated surface; the closer the light source is to the illuminated surface, the greater the illuminance on the illuminated surface. In addition, under the condition that the distance between the light source and the illuminating surface is constant, the illuminance of vertical irradiation is larger than that of oblique irradiation; the more inclined the light is, the smaller the illuminance.
What does the office illuminance have to do with? The first reaction of many people is that it is related to the number of lamps and the brightness of the lamps themselves. Of course, this is also a related factor. The more lamps and the brighter they are, the luminous flux can be increased and the illuminance of the office can be improved. In addition to the light problem, there are other factors, such as the hanging height of the light fixture, the area and shape of the space, the color and cleanliness of the walls, ceiling and floor, and so on.
The higher the lamp hangs, the more reflected light flux, and the overall illuminance of the space will be relatively improved. The larger the area of the space, the closer it is to the square, the more direct luminous flux, and the higher the illuminance of the space. The lighter the color of the walls, ceiling and floor, the cleaner the surface, the more reflected luminous flux, and the higher the illuminance of the space.
It can be seen that improving the illuminance of the office can be achieved by increasing the number and brightness of lamps, raising the hanging height of lamps, and cleaning the walls, ceilings and floors.
But isn't the increase in illuminance conducive to improving work efficiency? The answer is not necessarily.
The general conclusion of the current research is that although the improvement of the lighting level within a certain range can improve the work efficiency, with the continuous improvement of the lighting level, the improvement of the work efficiency will become smaller and smaller, until the negative efficiency (efficiency reduction) occurs. The point at which the efficiency decreases varies from task to task. Generally speaking, the more difficult the task, that is, the smaller the object and the lower the contrast, the higher the lighting level at which the efficiency reduction point appears.
By changing the characteristics of the task (that is, enlarging its size or increasing the contrast), it is more satisfactory in terms of visual effects than by increasing the lighting level. It is generally difficult to achieve the same level of work effect for visually difficult tasks (small size, low contrast) by simply increasing the lighting level.
Illumination reference for different places
General conditions: 100,000 LUX in summer sun; 10000 LUX outdoors in cloudy days; 100 LUX indoor fluorescent lamps; 300 LUX 60 cm desktops away from 60W desk lamps; 1000 LUX in TV studios; 10 LUX indoors at dusk; 0.1 LUX night street lights; candlelight (20cm away) Place) 10～15LUX.
