Summary:In alignment with relevant regulations, this article elucidates the definitions of emergency lighting and fire emergency lighting, and analyzes the differences in fire emergency lighting design between new and old residential projects.
The topic of whether emergency lighting in fire situations can be used for daily lighting was addressed, along with an analysis and discussion on the design and application of emergency lighting and evacuation signage systems in residential projects.
Keywords:Emergency Lighting; Centralized Control Systems; Non-Centralized Control Systems; Emergency Lighting Controller; Centralized Power Supply; Emergency Lighting Distribution Box
Introduction
On March 1, 2019, the GB51309-2018 "Technical Standard for Fire Emergency Lighting and Evacuation Guidance Systems" (hereinafter referred to as "the Technical Standard") was implemented, which introduced new design requirements for fire emergency lighting and evacuation systems (hereinafter referred to as "fire emergency lighting systems"). It adopted a completely new approach and design philosophy, significantly differing from traditional emergency lighting design. This article reviews the changes between the old and new standards, discusses the upgrades in fire emergency lighting design in residential building projects, the selection between centralized and non-centralized control systems, and analyzes the situations where fire emergency lighting can be used for daily lighting. It also explores the design and application of centralized control fire emergency lighting systems in residential projects.
1. Definition of Emergency Lighting and Fire Emergency Lighting and Evacuation Signage Systems
The Ministry of Housing and Urban-Rural Development defines emergency lighting in the GB50034-2013 "Standard for Lighting Design of Buildings" as: lighting that is activated due to the failure of the normal lighting power supply. Emergency lighting includes evacuation lighting, safety lighting, and standby lighting. It is required that emergency lighting be provided in the following places when the normal lighting power supply fails:
In locations where normal work or activities must continue, backup lighting should be installed.
In locations where personnel may be at potential risk, safety lighting should be provided.
Disaster lighting should be installed at exits and passageways where personnel must be evacuated to ensure safety.
The "Technical Standards" defines several key terms:
Fire Emergency Lighting and Evacuation Guidance Systems are designed to provide lighting and evacuation guidance for personnel during emergency evacuations and in areas that require continued operation during fires. The systems are categorized based on the control method of the fire emergency lighting fixtures into centralized control systems and non-centralized control systems.
② Centralized Control System: A fire emergency lighting system with an emergency lighting controller, which centrally controls and displays the operational status of the emergency lighting centralized power supply or emergency lighting distribution box, along with the connected fire emergency lighting fixtures.
③ Non-centralized control systems, where the emergency lighting system does not require an emergency lighting controller. Instead, the emergency lighting centralized power supply or emergency lighting distribution box controls the operation status of the connected fire emergency lighting fixtures.
④ Emergency Fire Lighting, a variety of lighting equipment used for personnel evacuation and firefighting operations, including emergency lighting fixtures and emergency signage fixtures. Emergency fire lighting is categorized based on the use location and functional requirements, as shown in Figure 1. The system is classified according to lighting purposes: evacuation lighting, evacuation guidance, and fire备用 lighting.
Update on Fire Emergency Lighting Design for Two Residential Projects
In the design of residential projects, the relevant requirements from several national codes and design standards, including GB50016, GB51348, and JGJ242-2011, are concurrently integrated. Emergency lighting should be installed in stairwells of high-rise residential buildings, as well as in their vestibules, elevator lobbies, or shared vestibules, and in corridors longer than 20 meters. The conventional practice has been to use integrated luminaires with built-in batteries for both normal and emergency lighting, very bright built-in battery-powered fire emergency lights, and continuously lit evacuation sign lights, all powered by a dedicated fire circuit.
During a fire, the fire automatic alarm and linkage control system disconnects the normal power supply, and the lighting products are powered by their built-in batteries for emergency lighting. After residential communities are handed over and put into use, there are quality variations and a certain lifespan for fire lighting products. To maintain reliability, property managers need to regularly inspect, maintain, and replace new products, which constitutes a significant human resource cost for residential community property management. The implementation of the "Technical Standard" has led to significant differences in the design of fire emergency lighting systems in residential buildings. The "Technical Standard" specifies the locations for fire control rooms, where the fire emergency lighting system should be of a centralized control type; for places with fire automatic alarm systems but no need for fire control rooms, a centralized control system is recommended; for other locations, a non-centralized control system can be chosen. Depending on the power supply methods of fire emergency lighting batteries, they can be categorized into two types: those using centralized power supply and those using built-in batteries. The two control methods of the system can be combined with the two power supply methods of the lighting batteries to form different systems. As shown in Figure 2.
Selection of Centralized and Non-Centralized Control Systems in Three Residential Projects
Typically, locations within residential complexes where fire automatic alarm systems are installed include: all areas of high-rise residential buildings over 100 meters tall; public areas in Class 1 and Class 2 high-rise residential buildings (including commercial service outlets and supporting facilities in residential towers); basement car parks equipped with mechanical smoke extraction systems that are interconnected with the fire automatic alarm system; commercial buildings with a floor area exceeding 1,500 square meters or a total floor area exceeding 3,000 square meters on any level; children's rooms in large and medium-sized kindergartens; elderly care facilities, and other similar areas. According to regulations, fire control rooms should be established within residential complexes. Therefore, the fire emergency lighting systems in the areas of residential complexes served by these fire control rooms, which have fire automatic alarm systems, should be of centralized control type. For public buildings that do not require fire automatic alarm systems, such as evacuation corridors, restaurants with an area over 200 square meters, business halls, meeting rooms, and office lobbies with an area over 400 square meters, non-centralized control fire emergency lighting systems can be used.
Not all public places require consideration for the installation of emergency lighting, such as:
Residential buildings with疏散elevations less than 27 meters, including evacuation corridors and stairwells.
②Public buildings with dining rooms, business halls, and areas under 200 square meters, as well as meeting rooms and office lobbies over 400 square meters, are not required to install automatic fire alarm systems.
③ Underground or semi-underground public spaces with a floor area of no more than 100 square meters; ④ Parking garages with no more than 50 parking spaces.
Analysis of Fire Emergency Lighting Usage in Daily Lighting in 4 Residential Projects
In residential projects, places that do not require emergency lighting are not involved in the issue of whether fire emergency lighting can be used for daily lighting. Regarding this issue, an analysis can be conducted in places with emergency lighting in residential projects: Article 3.1.6 of the Technical Standards requires that in residential buildings, when lighting fixtures are powered by their own battery packs, fire emergency lighting can be used concurrently for daily lighting. Additionally, Article 3.2.1 of the Technical Standards mentions that in residential buildings without a fire control room, places such as evacuation corridors and stairwells can opt for B-type lighting fixtures with self-contained power sources. If a centralized control system is used, and all lighting fixtures are installed at a height of 8 meters or less from the ground, A-type fixtures should be selected. For fire lighting used for both emergency and daily lighting, fire emergency fixtures powered by a safe voltage (36V or less) can meet the requirements for emergency lighting ground level minimum illuminance. However, it is challenging to meet the standard illuminance values for daily lighting as required by the regulations, as shown in Table 1.
In accordance with the "Technical Standards," non-centralized control systems utilize non-continuous lighting fixtures that can be activated by human presence or sound detection when powered by the main power supply under non-fire conditions. In the event of a fire, non-centralized control systems powered by their own battery packs should be capable of manually initiating the emergency start of the control system. They should allow manual operation to disconnect the main power output of the emergency lighting distribution box, while simultaneously controlling the emergency lighting of all non-continuous lighting fixtures and switching the light sources of continuous lighting fixtures from energy-saving mode to emergency mode. Specifically, in Type II high-rise residential buildings without fire automatic alarm systems, B-type emergency lighting fixtures with built-in battery packs should be installed in less than 20-meter-long evacuation corridors, open stairwells, and elevator lobbies, used in conjunction with daily lighting, and powered by non-centralized control B-type emergency lighting distribution boxes. Each B-type emergency lighting distribution box is set up with no more than 12 output circuits, with each output circuit in the electrical shaft designed to supply power to lighting fixtures on no more than 18 floors vertically. The non-centralized control B-type emergency lighting distribution boxes are powered by the normal lighting distribution box of the tower building and do not require communication or fire linkage functions, similar to general distribution boxes. Apart from the above, most areas in residential projects are not allowed to use fire emergency lighting for daily lighting.
Design and Application of Centralized Control Fire Emergency Lighting and Evacuation Guidance Systems in a 5-residential project
In residential projects, it is quite common to have a composition consisting of a group of high-rise residential buildings, supporting public buildings, and a Class I underground parking garage. For such residential projects that have a fire automatic alarm system and a fire control room, the fire emergency lighting system should adopt a centralized control system.
5.1 Lighting Design
Previous analysis has concluded that if the A-type lighting fixtures with built-in batteries are chosen, they are unlikely to meet the daily lighting intensity standards. In such cases, emergency lighting should be non-continuous. Based on surveys conducted by real estate companies and calculations of investment costs, the preference is for centralized power supply for fire emergency lighting. Therefore, in most high-rise residential community projects, centralized power supply systems with A-type fixtures are used. Since the installation height of sign lights in residential buildings is usually less than 3.5 meters, medium or small sign lights can be chosen. The emergency lighting response time of the light sources is no more than 5 seconds. For residential buildings over 100 meters in height, the continuous operating time of the lights on battery power should not be less than 1.5 hours after emergency activation; for buildings under 100 meters, the time should be at least 0.5 hours. The placement of emergency lighting in high-rise residential buildings should ensure the evacuation of personnel-related areas and provide basic illumination along evacuation routes, with specific locations and minimum illumination levels complying with Article 3.2.5 of the Technical Standards. Sign lights should ensure that personnel can clearly identify evacuation routes and directions, the location of exits, and their floor position, and should be placed in prominent locations to ensure visibility at any point along the evacuation path to avoid panic. For residents of residential buildings, it is common to be familiar with their living environment. Out of human instinct, in the event of a fire, they would undoubtedly flee down the ground-level stairwells of the building. Therefore, it is argued that directional sign lights may not be necessary in the ground-level stairwells of residential tower buildings, but it is necessary to set up floor indicator lights to reduce the panic of those escaping. This view is also clearly stated on page 35 of the National Standard Collection 19D702-7 "Emergency Lighting Design and Installation."
5.2 System Power Distribution Design
Luminaires are powered by a centralized power supply, which provides both the main power and battery power to the luminaires. After the output conversion between the main power and the battery power is achieved internally within the centralized power supply, the same distribution circuit powers the luminaires. No residual current protective devices are installed in either the input or output circuits of the centralized power supply. It is strictly prohibited to connect sockets, switchgear, and other loads outside the system to the output circuit. The design of the luminaire distribution circuit should comply with the requirements of Article 3.3.3 to 3.3.6 of the Technical Standards. It is common in residential buildings to have a scissors staircase as two separate escape staircases. The emergency lighting distribution method within the scissors staircase, in my opinion, can be achieved by two distribution circuits supplying alternating power to the two staircases (hereinafter referred to as "Method 1"). The distribution pipes of each circuit are concealed vertically along both walls, making it easier to install and more cost-effective compared to the method (hereinafter referred to as Method 2) where each staircase has its own independent circuit concealed along the inclined floorboards. According to the first paragraph of Article 3.3.4 of the Technical Standards, smoke-proof staircases and enclosed staircases should have separate distribution circuits, with the original intention of ensuring that emergency lighting within the staircases is not affected by other areas, thereby increasing the reliability of emergency lighting. However, the proposed Method 1 provides dual-circuit power supply to the two independent staircases within the scissors staircase, which is more reliable than Method 2. Even if one circuit fails, each independent staircase can still ensure 50% of the originally designed illumination, whereas in Method 2, if only one circuit fails, the service area of the staircase power supply circuit loses emergency lighting. (Figure 3) The centralized power supply, emergency lighting controller, centralized control system control, and system wiring design have, since the implementation of the Technical Standards, formed design principles that comply with most residential projects. I will not discuss them one by one.
Figure 3: Emergency lighting distribution method inside the Scissors Stairs
5.3 Emergency Lighting Design
In residential projects, areas that must remain operational and staffed during a fire (such as refuge rooms, electrical control rooms, fire control rooms, fire pump rooms, and self-provided diesel generator rooms) should simultaneously be equipped with backup lighting, emergency lighting, and evacuation signage. Backup lighting fixtures can be the same as normal lighting fixtures, maintaining normal illumination during a fire. They should be powered by a dual-source switching device within the lighting cabinet, utilizing both normal lighting power and a dedicated fire power emergency circuit. The emergency lighting and evacuation signage lighting installed in these areas can also serve as transitional lighting during power source conversion.
6 AnkoRay Selection Products
Based on the above design and requirements, our product selection is as follows:
7 Conclusion
Emergency lighting for fire situations is not only essential for ensuring the safe evacuation and orderly疏散 of personnel during a fire, but also for maintaining the stability of their daily lives. A well-designed and reliable emergency lighting system can prevent panic and chaos in the event of a power outage or fire. In residential buildings, the emergency lighting system, once damaged, often faces delays in maintenance and inadequate management, rendering the entire system ineffective and unable to fulfill its intended role during emergencies or fires, posing significant safety risks. The adoption of a centralized control-type emergency lighting and evacuation guidance system allows fire personnel to promptly detect the status of any component, playing a crucial role in improving management efficiency and reducing human resources investment.
Reference
GB50016-2014 (2018 Edition) Code for Fire Protection of Building Design [S]
[2]. GB17945-2010 "Fire Emergency Lighting and Evacuation Guidance System"[S].
[3]. GB51309-2018 "Technical Standard for Fire Emergency Lighting and Evacuation Guidance System" [S].
GB51348-2019 "Standard for Electrical Design of Civil Buildings" [S].
[5]. GB50116-2013 "Code for Design of Automatic Fire Alarm Systems" [Standard].
Feng Yuxian. "Design and Application of Centralized Control Emergency Lighting and Evacuation Guidance Systems in Residential Projects"
