（4）至于节能和延长灯泡寿命的问题，就目前国内的情况来看，很大一部分可以象中国银行总部大楼那样，结合天然采光和客人活动对亮度的要求，通过智能控制系统适时地进行调光，来加以解决。当然，节能方法还有许多，但已超出了本文的范围。
1.4 Direct lighting should be used instead of indirect lighting methods. Light grooves are currently widely used in commercial space lighting, even to an excessive extent. With the development of electrical light sources and lighting fixture manufacturing technology, direct lighting methods can now avoid the harm of uncomfortable glare to vision. Therefore, unless decorative requirements are met, it is best not to use various types of luminous grooves that are highly wasteful of luminous flux and inconvenient to maintain.
1.5 Use light sources with the same color temperature to avoid chaotic light colors. For the same functional area, surface, and object, use light sources with consistent color temperature to ensure a unified tone of the lighting environment. In terms of hotel lighting design, since the emphasis is not on conflict or drama, a unified tone is more in line with the characteristics of hotels. We have noticed that some domestic interior design companies still have many issues in this regard. For example, in the Longwang Hotel project, other aspects are good, but there are still some problems with lighting: some rooms use cool white light sources; some rooms have both warm white and cool white light sources, which makes people feel uncomfortable.
1.6 Choose lighting fixtures with high luminous flux efficiency
(1) Choose lighting fixtures with optimized parameters and high luminous flux efficiency. We often encounter situations where the total luminous flux of the light source is very high as stated, but due to the use of lighting fixtures with low luminous flux output efficiency, the theoretically calculated illuminance values and the actual measured values with a lux meter are quite different.
(2) It is recommended to entrust a unit with relevant testing equipment to conduct tests when there is any doubt about the efficiency parameters, light distribution curve parameters, etc. provided by the lighting manufacturer.
1.7 Select the appropriate lighting distribution for the different functional areas of the wine bar based on the room air ratio, and identify the lighting parameters such as light intensity distribution, central light intensity, and half light intensity to avoid losses in both aspects of luminous flux.
For example, the front hall of a bar is usually located in the podium of the building, and the ceiling is usually very high, with a height of over 6 meters being quite common. It is necessary to use lighting fixtures with a narrow beam angle and long throw distance to avoid excessive brightness at the top, while the ground and the area 1 meter from the ground where people are active are not bright enough.
Conversely, if such a beam pattern is used in areas with lower ceilings such as guest rooms, there will be issues such as excessive brightness on the ground and insufficient illuminance on vertical surfaces. The following two images compare the beam patterns of PAR38/80W/beam angle 120 and PAR56/300W/beam angle 400.
1.8 The higher the grade of the hotel, the higher the color rendering index of the light source should be.
(1) The color rendering of the light source is generally evaluated by the CIE color rendering index, which is a differential evaluation of the color display of more than 10 color samples, including human skin color, using the light source to be evaluated and the standard light source (full sky light). Broadly speaking, the higher the Ra of a light source, the better its color rendering.
(2) However, it should be pointed out that since Ra takes the average of the color samples, although the color rendering index of some light sources may be high, the appearance of a specific color may not be good. This point should be paid attention to in hotel lighting design.
(3) In domestic lighting standards and design practices, color rendering has not been given much attention, and it is usually emphasized that high color rendering index light sources are only needed in places with color discrimination requirements. In fact, it is important for guests to have a healthy skin tone in places where people have more contact with each other, especially in hotels.
(4) Additionally, a light source with good color rendering can have a lower illuminance under the same conditions than one with poor color rendering. This is not to say that color rendering can replace some of the illuminance, but rather that it makes the perception clearer for humans.
The key issues of hotel lighting go far beyond the above, this article only involves the issues that the author believes are prominent in current lighting design practice, for the consideration and discussion of lighting design colleagues.
