Interpretation of relevant provisions of electrical lighting in "Electrical Design Code for Medical Buildings"

In order to better understand and implement relevant provisions for the majority of medical building lighting design, construction, scientific research and hospital construction and management personnel, this article briefly explains and explains the technical contents of the main provisions of the chapter.

Coordination between 1 technical parameter and current standard

This specification is an industry standard. It was prepared in November 2008. In the preparation of more than four years, it has been continuously coordinated with relevant national and industry-related norms and standards. The main specifications and standards for coordination of electrical lighting are GB50034-2004 "Architectural Lighting Design Standards", Jianbiao 110-2008 "General Hospital Construction Standards", JGJ16-2008 "Civil Building Electrical Design Specifications", GB50016-2006 "Architectural Design" Fire Code and GB50763 "Accessibility Design Code".

1.1 About illuminance standards

GB50034 "Architectural Lighting Design Standard" is the national standard for architectural lighting design in China. It has authoritativeness. In order to handle the coordination with GB50034, the relevant provisions of the lighting design of this code have adopted the provisions of the national standard. Generally speaking, the practice is not repeated, but it is necessary to supplement and refine it from the actual situation, mainly in places with large traffic flow, or in common rooms, etc., and some fields need to be repeated in line with the national standard. As the preparation of this specification is in the past, GB50034 is revised, so the preparation of this specification is mainly coordinated with its 2004 edition. Compared with the medical building illuminance standard values ​​given in GB50034-2013 "Architectural Lighting Design Standards", the supplementary part of Article 8.2.1 of this code is shown in Table 1.

The illuminance values ​​in Table 1 are basically equivalent to the standard values ​​of the relevant places in CIE S 008/E-2001 "Indoor Workplace Lighting", but in some places, the illumination value of general illumination is still lower than CIE, such as: general inspection room The standard of CIE is 500lx, the standard is 300lx; the standard of operating room, CIE is 1000lx, this standard is 750lx, etc. This is mainly for coordinating with national standard, and starting from the current national conditions in China.

1.2 About the color rendering index of the operating room light source

GB50034 "Architectural Lighting Design Standards" stipulates that the color rendering index (Ra) of the operating room light source should be 90, but this is the requirement for the special shadowless lamp for surgery, or all the illumination sources in the operating room (including general illumination source and surgical special shadowless lamp). The requirements of the light source are not given. According to the investigation, the general illumination of the operating room in China often uses fluorescent lamps to surround the circumference of the surgical lamp on the ceiling of the operating room. In the past, fluorescent lamps with a color rendering index of 90 or above were not produced due to domestic fluorescent lamps. Mainly rely on imports, the price is higher, so most hospital operating room lighting design regards the national standard as the requirement for surgical lamps, and the general lighting uses fluorescent lamps with color rendering indexes of 80 and 85.

After reviewing the CIE standard, the color rendering index (Ra) of the operating room source is 90, and there is no specific surgical light. Article 8.2.4 of this specification finally stipulates that “the color rendering index (Ra) of the operating room light source should not be less than 90”, which is in harmony with the CIE standard and the national standard, and does not specifically refer to the surgical lamp. This standard is understood to be primarily a requirement for operating rooms belonging to Class 2 locations. Considering that China's medical and health undertakings have developed greatly in recent years, and the construction demand is strong, at the same time, China's electric light source production enterprises have also made considerable progress, regardless of the feasibility of product technology or the perspective of engineering cost. It should be appropriate.

1.3 Relevant regulations on emergency lighting

Emergency lighting includes safety lighting, backup lighting, and evacuation lighting. The emergency lighting in Section 8.4 of this code mainly includes the provisions on how to set emergency lighting, the illumination standard of emergency lighting, the continuous power supply time of emergency lighting, and the conversion time of emergency lighting power supply after the power failure.

The illuminance of the evacuated lighting must ensure that the evacuation channel is effectively identified, and the current standards for illuminance standards for evacuation lighting vary, as shown in Table 2.

It can be seen from Table 2 that the general horizontal evacuation channel is required in Article 8.4.2 of this standard, that is, the “minimum horizontal illumination of the evacuation lighting in other evacuation areas shall not be less than 3.0lx”, which is stricter than the national standards and other industries. The standard is because the service targets of medical buildings are mainly sick patients, and some need rescuers to assist in evacuation. It should be appropriate to raise the standards appropriately. The article has added underground evacuation areas, mainly for the medical floors of some hospitals, or for evacuation routes to outdoor and urban security areas. The standard emphasizes that the minimum level of illumination on the ground in these underground evacuation areas should not be low. At 5.0lx.

Regarding the continuous power supply time of emergency lighting, Article 8.4.3 of this standard requires “the continuous power supply time for safety lighting in places such as operating rooms and rescue rooms involving personal safety, the tertiary hospital should be greater than 24h, and the secondary hospital should be greater than 12h. The hospital below the second level should be more than 3h. This regulation is based on the characteristics of the hospital. It can be completed within 12 hours after the operation of the second or higher hospitals for patients undergoing surgery or rescue. The surgery or rescue of the hospitals below the second level is generally 3 hours. Can be completed inside. At the same time, this article echoes the first paragraph of Article 4.4.5 of this code to correspond to the actual situation of continuous operation of the operating room in China's tertiary hospitals.

Targeting the content of 2 articles

In China, the standards related to architectural lighting, the national standard has GB50034 "Architectural Lighting Design Standards", the industry standard has the JGJ16 "Electrical Design Code for Civil Buildings" (referred to as "People's Regulations"). The system model of this standard needs to be in accordance with the established system of building electrical standards, and the relevant chapters are basically consistent with the “civil regulations”. If the content is duplicated with the current national and industry standards, the meaning of the standard is lost. Therefore, the main technical content of the provisions of this Code must be targeted, that is, in line with the nature of medical buildings, reflecting the characteristics of medical buildings.

2.1 About the color characteristics of the illumination source

The color characteristics of light and architectural decorative surfaces are one of several important factors that make up visual comfort. As a standard for regulating the electrical lighting design of medical buildings, it is necessary not to require the color characteristics of its illumination source. The color appearance of the light source is represented by the correlated color temperature of the light source. Article 8.2.3 of this code stipulates that “the color chart of medical building illumination source should be intermediate color, and the correlated color temperature should be 3300k~5200k.” In 8.3.2, “color temperature of general illumination source in the same place in the room is also required. Should be consistent; in addition to special lighting for treatment, other general lighting should not use colored light, indoor decorative lighting should not use colored light." Even in the number of 8.4.5 for the safety lighting and the color temperature of the backup lighting source is also proposed The requirement is “should be consistent with general lighting”.

The main reasons for the above requirements are: (1) the need for medical construction services. Hospitals are places for special people who are sensitive to the colors in the field of view. In addition to the illuminance, the choice of the color temperature of the indoor light source should also take into account the psychological feelings of the person. The middle color gives a soothing and peaceful atmosphere, which is suitable for most places of medical construction. In the ward, the low color temperature in the middle color (some with low color temperature) can be used to give a warm feeling. (2) Responding to the establishment of the standard 110-2008 "General Hospital Construction Standards". Article 33 of the standard stipulates that the architectural decoration and environmental design of general hospitals should be beneficial to the physiological and mental health of patients and reflect the characteristics of fresh, elegant and simple industry [6]. (3) Standardize the floating and luxuriant phenomenon of color light abuse in the decoration and lighting design of medical buildings in recent years, and guide the design concept of establishing correct human care.

2.2 About lighting methods and types

In Section 8.3, “Lighting Methods and Types”, Section 8.3.2 provides general information on the general lighting in medical buildings, which differs from other buildings in terms of visual comfort and architectural functions, medical process requirements, etc.

The color temperature and color rendering of the light source for general illumination in the same place in the room should be consistent;

In addition to special lighting for treatment, other general lighting should not use colored light;

The ward lamp should use a matt white reflector;

The luminaires leading to the operating room walkway in the ward should not be placed in the middle;

Clean lighting should be used in places with cleanliness requirements such as operating rooms, neonatal isolation wards, and burn wards;

Moisture-proof lamps should be used in wet rooms such as laundry rooms and disinfection rooms;

The lamps for magnetic resonance equipment rooms shall be made of non-magnetic materials such as copper, aluminum and engineering plastics;

Psychiatric wards should use ceilings or recessed luminaires with protective covers, and so on.

Article 8.3.3 of this code sorts out the special features of the local lighting in medical buildings that are different from those of other buildings. For which fields need local lighting, lamp selection and how to install, operating room special lamps and The illuminance of the dental shadowless lamp has been requested.

In addition, Articles 8.3.4 to 8.3.7 provide ultraviolet disinfection lighting for night illumination of hospital ward areas, waiting areas, infectious disease clinics and wards, operating rooms, blood banks, disinfection supply rooms, mortuaries, garbage disposal stations, etc. Decorative lighting gives the corresponding requirements. Among them, in the implementation of Article 8.3.5, according to the "Hospital Agency Disinfection Technical Specifications" WS/T367 [4], disinfection of the surface of the article, preferably using a portable UV sterilizer for close-range movement, UV The lamp is suspended by illumination. Small items can be placed in an ultraviolet disinfection box, and indoor air can be disinfected by indirect or direct irradiation. When indoor suspension ultraviolet disinfection is used, the indoor installation of ultraviolet disinfection lamps (30W ultraviolet lamps, intensity at 1.0m > 70uW/cm2) is not less than 1.5W per cubic meter, and the irradiation time is not less than 30min.

2.3 About lighting control

The purpose of electrical lighting control is on-demand lighting, easy to use and manage, to achieve good visual effects, and to implement lighting energy saving, requiring safety, reliability, flexibility and economy. In Section 8.5 “Lighting Control”, Article 8.5.1, from the actual situation, the setting of the lighting switch of the general building of medical building is given according to centralized control, partition or group control, single lamp control, etc. . Article 8.5.2 provides requirements for the setting of lighting switches for special places, for a total of seven models. Among them, the first, third and sixth paragraphs of the standard terminology are “should”, all of which are considered from the perspective of safety; other sections are summed up in the actual operation experience, which is conducive to medical process operation and safety management.

2.4 About medical logo lighting

Due to the large number of medical departments and medical equipment, the modern medical building has a complex function and a large building volume, which provides convenient medical treatment for patients, relieves the nervousness of patients and their families, and ensures that the hospital is in a building under normal operation and emergency conditions. Personal safety, medical identification has become an important part of modern medical architecture. Article 43 of the “Building Standards for General Hospitals” of Jianbiao 110-2008 stipulates that “general hospitals should be equipped with a complete, clear and eye-catching identification system”.

Section 8.6 of this specification, "medical identification lighting", is a unique section that distinguishes it from other architectural lighting and is an innovation in lighting design in China. This section contains the categories of medical identification lighting, setting requirements for marking lighting, average brightness requirements for indoor signs, and power distribution and grounding requirements. Article 8.6.1 of this standard indicates that the medical label may include the guiding sign of the medical building, the barrier-free sign and the safety warning sign. Since there is a logo, it is necessary to make the logo clear and identifiable. In addition to the location of the installation, it is inevitable to use electric light source illumination. Therefore, this standard reminds that the design should use electric light source illumination.

The setting of medical identification lighting includes setting principle, setting position, labeling specification, text graphic and color, surface brightness, etc., and there are many contents. Article 8.6.3 of this specification only identifies the height of the sign from the ground and the emergency channel identification from the safety point of view. Requirements for lighting, signage lighting at the entrance to the machine room where radiation protection is required.

According to the investigation, the medical signs of hospitals in China can be divided into three categories: non-lighting, internal light transmission and LED display . For the design of the building itself, the architectural design, lighting design and logo design should be carried out simultaneously, and the appropriate location should be considered and the appropriate lighting can be obtained. At the same time, the brightness of the logo should not be too high, and it should be suitable for the brightness ratio of the indoor environment in which it is located. Too high will cause light pollution. According to the environment in which the indoor sign of the medical building is located, the average brightness of the mark shall be in accordance with the provisions given in Article 8.6.4, that is, when the mark area is less than or equal to 0.5 m2, regardless of which of the above three categories. The average luminance is 400 cd/m2; when the identification area is greater than 0.5 m2 and less than or equal to 2 m2, the average luminance is 300 cd/m2.

3 articles on technical requirements for suppressing glare

Although the provisions of this standard concerning glare suppression are not many, they are extremely important for medical buildings. In 8.1.2, “Building a comfortable light environment” is proposed as the goal of electrical lighting, given in the “General Provisions” section. Article 8.2.5 clearly states that “medical architectural lighting should avoid direct glare from interfering with patients and those with fine visual medical operations”. Specific requirements are imposed on the uniform glare value (UGR) of the halls, registration halls, waiting areas, and other places where patients must pass. Section 8.3.2, paragraph 2, requirements for the selection and installation of luminaires in the ward, paragraph 3, requirements for the arrangement of lamps in the aisle leading to the operating room, and 8.3.7 stipulates that “the ward building (district) is not suitable for setting up the city. Night lighting, etc., will all avoid glare problems with independent terms.

CIE proposed in 1995 to use UGR as a quantitative indicator for assessing discomfort glare. The subjective feelings of the uncomfortable glare corresponding to its value are shown in Table 3 [5]. It can be seen from Table 3 that the UGR values ​​(19, 22) of the places covered by Article 8.2.5 of this Code are not very strict indicators. For patients, this is the minimum.

Lighting should pay attention to people's needs, people's feelings, people's emotions [1]. The light environment of modern medical buildings should be comfortable for both patients and doctors. The patient has a comfortable visual environment and walks into the hospital. The lighting brings light, comfort and warmth, so as to put down the feeling of suppressing fear and enhance the confidence to overcome the disease. The doctor has good workplace lighting, not just providing good The visibility of the job should be able to work easily and comfortably. Of course, the realization of "visual comfort" is achieved by a combination of illumination, brightness distribution, glare, light and color characteristics of the architectural surface, flicker, natural light and maintenance. This specification will highlight the issue of glare with separate provisions, which is intended to ensure that the low-limit indicators specified in the standard are to be implemented in medical building lighting design.

4 Lighting energy saving for medical buildings

At present, lighting energy conservation has become an important aspect of energy conservation in the whole society. However, when lighting energy is implemented, some have lowered lighting standards, which is not desirable. Lighting energy conservation for medical buildings should be emphasized under the premise of ensuring lighting standards. From the survey, at present, the lighting of hospitals in China does have a lot of energy-saving space on the one hand, but on the other hand, the quality of lighting is not up to standard, and the phenomenon that the light environment is unsatisfactory is still serious.

Section 8.7 of this specification sets forth the basic requirements for energy saving in medical building lighting. Among them, Article 8.7.7 “The interior lighting design of medical buildings should use natural light,...”, which is not only the focus of lighting energy conservation, but also the design of medical building schemes. Due to the large scale and centralized layout of equipment, the comprehensive hospital may bring huge space in the building space, relying on electric light source, but at the expense of lighting, and sunlight is indispensable for people's physical and mental health. Therefore, the architectural design needs to be planned. At the beginning of the design phase, we worked closely with lighting designers to fully exploit the natural lighting technology to provide patients and doctors with more ecological space and natural light for energy saving.

5 Conclusion

Due to the advancement of society and science and technology, medical concepts, medical institution models, and medical building forms are constantly changing. In addition to China's vast territory and unbalanced economic development, the relevant provisions of the standard electrical lighting need to be flexibly implemented. It is also expected to receive more constructive feedback; at the same time, due to the rapid development of technology, materials and processes, it is difficult for the specification to track the latest technological trends in real time, and there will be omissions and defects in technical requirements. These issues are waiting for the future. Keep up and adjust.