Smoke Control in Shopping Complex - Literature review Example

1.0 Literature Review 1.0 Introduction During the recent decades, the concept of the shopping centre has become increasingly important. At present, more major towns and cities in both the developing and developed economies have developed such centres (Lougheed 2000; Colt 2015; Bennetts et al 2006). However, to the design teams, such projects represent newer challenges of compliance with the fire safety codes, which also affect the design. With nearly 100,000 people entering a typical shopping centre in a major city, the burden of responsibility on the design team to provide safety, particularly in multi-storeyed shopping centres, where smoke and hot gases are major hazards during fires (Colt 2015). Still, certain architectural aspects of these shopping centres may not have satisfactory fire safety codes. According to Bennetts et al (2006), smoke spreading may be a significant problem to shopping complesxes and therefore smoke control is crucial. In this regards, offering sufficient evacuation time and smoke control systems have been suggested as effective methods that should be integrated in buildings to keep the smoke layer above the safety height (Ball, D 1999; Bennetts et al 2006; Cox 2015). Hence, smoke control and smoke movement in shopping malls is crucial and investigating smoke movement and smoke controls within the shopping malls have become the objective this paper. Therefore, this review of literature explores into the issues surrounding smoke control in shopping complexes. 1.1 Typical smoke control in shopping complexes and reasons of using it Fires in shopping complex can cause a severe threat to occupants due to incidences of smoke migration. In a discussion of the principles of smoke management in atrium buildings, such as a shopping mall, Lougheed (2000) mentions that such buildings present a significant challenge to fire protection due to their height (of more than 20 metres), which undermine efficiency of automatic sprinkler systems. Additionally, they lack the floor-to-floor divisions that can limit the potential for fire and smoke to spread from one storey to the next. Such limitations are widely discussed in literature. Indeed, a related survey by Colt (2015) showed that the escape routes within the shopping complexes are of utmost concern as they are also vulnerable to smoke spread, save for when the smoke management measures are integrated. 1.1.1 Smoke hazards in shopping complexes According to Lougheed (2000), the hazards from smoke in the buildings vary from the toxic gases such as carbon monoxide and narcotic gases, both of which have a potential to render an individual unconscious. Others include poisonous hydrogen cyanide as well as irritants like acrolein that disorientate individuals, thus hampering evacuation and rescue missions. Additional hazards include reduced oxygen levels, leading to suffocation. The high temperature from the fire is also potentially harmful to individuals immersed in smoke or exposed to radioactive materials. The reduce visibility due to smoke, hence hampering rescue and evacuation attempts (See Figure 1). Figure 1: Smoke hinders visibility 1.1.2 Smoke control in shopping complex According to Fang et al (2007), having knowledge of the fire movement inside a building is crucial in architectural design. In their study of smoke control and movement in sustainable atrium buildings, Fang et al (2007) showed that smoke is the initial and utmost rapidly developed threat to human life during fire incidents in shopping complexes, where smoke bring about many problems. Smoke control is therefore a crucial set of practices for guaranteeing safety in shopping complex spaces. However, Colt (2007) emphasised that for smoke control to be effective, it has respond to the principles of smoke movement. This idea was earlier supported by Morgan and Gardner (1991), hence calling for a need for a review of the principles of smoke movement. Following their examination of smoke movement in shopping centres, Morgan and Gardner (1991) explained that smoke emanating from a fire inside a unit shop within the shopping complex rises in a spiralling plume towards the ceiling. As the smoke rise, air joins the plume. This leads to reduced temperature and increased volume of smoke (See Figure 2). Figure 2: Typical smoke movement in malls (Colt 2015) Figure 3: Smoke and plume in a shopping complex fire (Lougheed 2000) Ultimately, the smoke outspreads below the ceiling in turn forming a layer that becomes deeper as the smoke fills into the shop (See Figure 4). When the layer intensifies, the height by which the plume can rise lessens. Less amount of air becomes entrained leading to higher temperature on arrival at the smoke layer. Subsequent to this, the smoke flows out of the shop and further into the mall. The shift of direction of the flowing smoke leads to greater level of mixing with the surrounding air (Morgan and Gardner 1991). The degree of hot gases that carry the smoke particles is largely dependent on the rate and size of burning. The smoke then flows from the shops into the mall rises to ceiling of the mall. Air also entrains into the smoke during the rise (Morgan and Gardner 1991). Absence of smoke control measures allows the gases to flow the length of the mall at speeds of 1 to 2 m/s, which is much rapid than the pedestrian’s likely escape speed when the mall is thronged with evacuees (Colt 2015). In the event that smoke eventually gets to the end a closed mall, it plummets to low levels before it draws back to the fire. In the event that the end of the mall remains open that air that blows into as well as across the opening leads to mixing and disturbance. Again, the smoke at low level draws back to the fire. In such two scenarios, a mall with a single-storey mall would be filled with some in minutes (Colt 2015). As it is often impractical to prevent smoke from gaining entry into the mall, save for the relatively large shops, having a smoke control system is vital from controlling and removing smoke and heat (Colt 1991). A study by Morgan and Gardner (1991) used these principles of the buoyancy intrinsic in fire gases to ensure that the gases are kept safely above the evacuees’ head the malls. Following his study on smoke controls in malls, Morgan and Gardner (1990) suggested three vital features of a smoke ventilation system that function collaboratively in smoke control. The first was that a means for creating a smoke reservoir has to exist to avert smoke from spreading laterally as a result leading to extreme loss of buoyancy. The research went on to argue that the reservoir needs to be designed in a manner that contains the base of the smoke layer beyond the height of the head. In general, malls that have been designed with elevated ceilings tend to permit a deeper smoke reservoir and therefore tend to be more helpful as smoke ventilation system compared to the low yet narrow malls (Morgan and Gardner 1991). The second feature for smoke control that Morgan and Gardner (199i) suggested is that extraction of smoke should take place at the reservoir, as this would avert the smoke layer constructed underneath the design depth. Morgan and Gardner (1990) speed of the exhaust has to be equivalent to the speed at which the smoke flows into the reservoir from underneath. The third feature, as suggested by Morgan and Gardner (1990), is that because the gases that are extracted are made up mostly of air that is entrained to the original gases of the fire, fresh gout of air has to flow into the mall to replace it. It has to enter at a speed that is equivalent to the speed of smoke extraction in addition to a low sufficient height that should not entrain with the smoke prematurely. The general approaches to management of smoke include installation of automatic sprinklers and restricting the use of combustible furnishings and construction materials (Lougheed 2000). Additionally, the “active” approaches include venting smoke from the atrium using openings within the ceiling or even fans or mechanical exhaust systems to restrict smoke and reduce its spread. Figure 5: protected floor space and vestibule (Lougheed 2000) 1.2 Fire safety issues in shopping complexes According to Cliath (2012), shopping complexes have significant potential for loss of property and life during a fire incident and therefore calls for utmost management standards to make sure that the risks are managed using appropriate systems. Fong (2008) agrees with this conception and submits that a common element needed for multi-fatality fires is when the occupants fail to pursue the right actions on discovering fire, or once an alarm has been raised. Consistent with these arguments, Ball (1999) argues that only a mix of effective management and sufficient training can guarantee that rights actions are taken. Cliath (2012), however, an effective fire safety management structure should offer provisions for replacements in the event of absence of individuals with certain responsibilities. The structure, as Cliath (2012), adds, should as well have a means to reaching the fire and rescue service and emergency services liaison officer. However, this would not automatically guarantee fire safety at the complex malls, as it should have provisions for change management at the mall. Indeed, it could be reasoned from this perspective that the idea of change management is the reason Cliath (2012) stressed a need for fire safety management structure at the shopping complex that reflects the change in the work patterns or operational management structures at the mall, yet also reflecting the recurrent changes in procedures and responsibilities. Hossain and Suraya (2013) view safety to go beyond just a condition where the human occupants of a shopping complex are from injury, hurt, or property losses. Hossain and Suraya (2013) defined safety as an unfailing and a consistent control of harm. In employing this approach to safety, the researchers seemed to imply that a minimal degree of occupational safety would be attained once the seriousness and frequency of occupational accidents are reportedly at a tolerable level. Basing on an organizational and technical a viewpoint, safety could be considered a feature of a system, which is the same as the similar the property of being dependable or of quality. This perspective appears to b e consistent with that of Hossain and Suraya (2013), where they hint to the issue of safety audit to identify and evaluate the general employee safety programs and safety conditions. The researchers were pointing to the safety of people at shopping malls and the need for safety audit to determine the potential risks. The safety audit aims to keep the customers safe and delivery of safe environments. According to Hossain and Suraya (2013), a safety audit includes the practical processes used in continual evaluation and monitoring of the progresses of its safety programs. It essentially amounts to verification, which is central in substantiating fire safety in complex shopping malls. A basis for this is since the audit enables the designers to verify whether a building is concisely built consistent with the specifications of the pre-accepted performance requirements, including the design to control the development and spread of fire and smoke inside the shopping mall complex. The performance requirements for fire safety, according to Nystedt (2011), include measures to ensure the stability and load-bearing structures, where the designers design a building that has adequate load-bearing and stability capacity during a fire incident to avoid collapse. The design should as well ensure that the spread and development of fire and smoke inside the building is controlled to minimise damage to property and injuries to the evacuees during a fire incident. It also needs to make provisions for integrating fire fighting equipment and furnishings in the mall, where the building surface materials do not contribute to fire development and spread to unacceptable levels. Nystedt (2011) adds that the performance requirements for fire safety should also make provisions for safe escape of evacuees during the time required for escape, where fire effluents , smoke and heat do not hamper escape. This comprises providing details of the escape routes, and constructing escape routes. They are an integral part of fire safety design as they incorporate the performance requirements to a shopping complex. In commentary regarding the fire safety issues in atrium buildings like malls, Gollner et al (2012) commented that the design and engineering factors are essentials. In their view, the fire protection engineers should be an integral component of the design team specifically during the early stages, into the construction and ultimately into the operational use of the building. Essentially, the comment was anchored in the conception that the large mall complexes pose potential challenges to both the design team and architects sine they are inherently multi-functional assembly buildings that provide visitors with a combination of retail and leisure outlets like retail stores and multiplex cinemas. An additional reason for including the engineers is because failure to integrate fire protection system at the initial stages of design would make it difficult to optimize the entire system. Hayward (2008) seems to agree with the idea and adds that fire fighter life safety need to be also integrated during the design process. 1.3 Characteristics of shopping complexes According to the Department of Homeland Security (2004), a shopping complex is typically made up of a flat roof, where certain areas have comparatively large spans, clear storeys, and skylights, a built-up roof membrane. Douglas (2006) also mentions additional features as including metal stud walls that have exterior insulation and finishing system (EIFS) cladding, stucco, or brick veneer cladding. Additional features include three-dimensional space framing, or steel- or light-metal framing fitted with glasses. The large complex malls, as the Department of Homeland Security (2004) discusses, usually have a single or two stories. On the other hand, the enclosed malls contain air-conditioning (HVAC), ventilating, and heating systems, in addition to telecommunication and electrical systems, as well as sewage, plumbing, and water systems (Douglas 2006). The International Code Council (ICSC ) also adds that a typical shopping complex, such as a regional centre, is often enclosed with the interior containing a sequence of stores linked by a common causeway or a parking that surrounds the exterior perimeter (See Figure 6). Conversely, shopping complexes like the super-regional centres, which resemble the multilevel shopping complexes, contain anchor stores that are essentially the conventional discount department stores or mass merchant stores (Department of Homeland Security 2004). Although such common features apply to a majority of the malls, certain configurations and exemptions make each of these facilities unique. For instance, the Department of Homeland Security (2004) provides statistics of 38 malls in the United States in 2000 that had 1.7 million feet2 of GLA. Of the malls, 15 has a single storey, 13 had two stories, five 5 had three storeys while four had four stories, while one was unclassified. At the same time, fifteen single storey shopping complexes had 10 differing configurations. On the other hand, thirteen were two-storey malls with seven differing configurations. The three- or four-storey shopping complexes had been configured like the rest in the category (See Figure 7) Figure 6: Interior of a multi-level shopping complex Figure 7: Aerial view of one-storey shopping complex An addition feature of the shopping complexes, as suggested by Douglas (2006), is that they often contain numerous entrances such as through the street, the parking areas, anchor stores, and mass transit, with the last one often having multiple entry points also. Several shopping complexes also contain delivery entrances at the back of stores. According to Reikli (2012), the airy and open spaces in most enclosed mall designs are beneficially as they can mitigate certain impacts like dissipation of smoke. The large shopping malls often contain an attached auxiliary facility that is embedded to their structure, such as office premises and space, hotels, cinema complexes, and amusement parks. Such facilities are an addition to the mall’s multiple entrances and exits (See Figure 8). For instance, figure Krol (2011) shows the floor plan of a mall with an attached hotel. Not shown is an office building that also is attached to the facility. Figure 8: Shop units at a shopping centre (Colt 2015) According to Chicago Association of Realtors (2014), the design of the shopping centre needs to comply with the building code requirements, which differ depending on the number of stories, whether single-level or multi-level mall. An example includes the U.S. Shopping-Center Classification Codes, as a requirement by the ICSC (See Figure 9). Figure 9: Table listing U.S. Shopping-Center Classification Codes For instance, the construction materials have to confirm to the precise fire ratings. These codes touch on different aspects of the building plan, including the egress passage ways and staircases, escape routes, specific an corridor dimensions, fire walls, as well as provisions for disabled occupants. The same as for most buildings, fires safety is a significant requirement within an enclosed mall. These mainly comprise the means of escape in addition to the smoke control requirements, which have become more stringent given the recent developments of the UK legislations in compliance with suggestions of the European Union (Douglas 2006). The main technical considerations for fires safety in the malls include proper smoke evacuation, means of escape and sprinklers. Douglas (2006) offered to mention these features in details. Regarding the means of escape, he explained that the requirements of designating fire exits in any roofed shopping centres have been altered by BS 5588: Part 10: 1919: code of practice that seeks to address the fire safety needs while constructing the shopping complex (Douglas 2006). For each unit of the shops, it is further required that the maximum floor space should be two square metres per person. This seeks to determine the capacity that each escape route can accommodate in each storey while exiting the building during a fire. Regarding smoke evacuations, Douglas explains that since smoke is the key killer during fires, the shopping complexes have exhaust systems designed to eliminate excessive smoke without the need to fan the fire. Hence, smoke is vented into the roof of the shopping complex. As regards the sprinklers, Douglas (2006) explains that the sprinklers form a section of the smoke ventilation that is located in the units of shops to prevent the spread of fire, beyond the acceptable safe limit. Douglas (2006) explains that sprinklers are installed in the malls when they have adequate combustibles capable of supporting a fire that is larger than the design fire size of about 5 Mega Watts, 12 metres perimeter. 1.4 Accidents related to shopping mall fires and statics According to Embury (2012), the changing nature of the retail sector has implications for re-examination of fire safety. Embury (2012) conducted his survey in the United States where he cited statistics showing that the United States has some 7 billion square feet of shopping centre space, yet embody insignificant safety risks because of the general conformity with the fire safety requirements and shopping centre buildings codes, despite the high number of fires. Still, similar problems affect the malls in China and UK. To this end, as the faces of shopping complexes change, it is also crucial to examine how small insignificant fires may have damaging effects at the mall. Several fires have occurred globally during the last decade, among the worst in the case scenarios. Bennetts et al (2006) argues that the fire incidents in shopping complexes in the developed nation such as the United States, United Kingdom, and Australia have generally been lower. In fact, only minimal fires have been reported. For instance, Embury (2012) undertook statistics of the fires in the United States over a 10 year period, between 1983 and 1993, and examined 77,996 fires that were mostly minor. Of these fires, only 86 deaths had been reported. The development nations, as could be deduced from current and past literature, have experience significant loss of property and life at the shopping centres. Embury (2012) explains that this is because of the general reluctance to comply with the building codes and fires standards. Embury illustrated one that happened in 2004 in Paraguay that left 500 people injured and 364 people dead. The fire began at a fast food outlet inside the Ycuá Bolaños shopping complex before spreading the outskirts of Asunción. The three-storey shopping complex has a throng of shoppers of all ages, including the small children, adults and the elderly. An investigation into the fire later confirmed that the fire had started at a poorly-maintained grill chimney at a food court in the mall. An explosion from the fire created a shock wave that broke external windows, thus permitting a surge of oxygen, leading the into the basement, and cutting off lower level escape routes. Still, it could be reasoned that the number of fires are fast reducing in both the developed and developing countries due to the emergence of stricter building standards that specify fire safety measures -- from detection to escape and rescue systems. According to the Geneva Association the cost of fire in the developed nations reduced between 2002 and 2012 from 0.28 percent to just about 0.16% of the GDP, while the risks of death of fire have plummeted to 1.34 from 1.88 per 100,000 during the same period. In 2012, fire killed 19 people and left 13 children trapped inside a nursery at the Villaggio mall in Qatar. The mall had quickly filled with smoke after the fire broke in May 2012. The evacuation processes had failed, leading to chaos at the exit due to poor design of the structure (Dickinson 2013). Conclusion Having knowledge of the fire movement inside a building is crucial in architectural design. Smoke is the initial and utmost threat to human life during fire incidents in shopping complexes, as they hamper visibility, cause suffocation, and delay evacuation. The shopping complexes also present a significant challenge to fire protection due to their height (of more than 20 metres), which undermine efficiency of automatic sprinkler systems. They also lack the floor-to-floor divisions that can limit the potential for fire and smoke to spread from one storey to the next. Therefore, the shopping complexes have significant potential for loss of property and life during a fire incident and therefore calls for utmost management standards to make sure that the risks are managed using appropriate systems. The shopping complex should as well ensure that the spread and development of fire and smoke inside the building is controlled to minimise damage to property and injuries to the evacuees during a fire incident. It also needs to make provisions for integrating fire fighting equipment and furnishings in the mall, where the building surface materials do not contribute to fire development and spread to unacceptable levels. The structure should as well have a means to reaching the fire and rescue service and emergency services liaison officer. The main technical considerations for fires safety in the malls include proper smoke evacuation, means of escape and sprinklers. Reference List Ball, D 1999, "Smoke Control In Special Structure," International Journal on Engineering Performance-Based Fire Codes vol 1 no 3, pp.134-147 Bennetts, I. Thomas, I & Poh, K 2006, “Design of Sprinkled Shopping Centre Buildings for Fire Safety," Building With Standards Chicago Association of Realtors 2014, Anatomy of a Shopping Center, viewed 25 Jan 2015, Cliath, A 2012, Fire Safety Management of Shopping Centres with Covered Malls, viewed 25 Jan 2016, Colt 2015, Smoke Control in shopping Centres, viewed 17 Jan 2016, Department of Homeland Security 2004, Characteristics and Common Vulnerabilities Infrastructure Category: Shopping Malls, viewed 25 Jan 2016, Dhanmondi, Dhaka And Application Of Safety Audit As A Preventive Measure," Daffodil International University Journal of Business and Economics, Vol. 7, No. 1, pp.19-31 Dickinson, E 2013, "Five sentenced over Doha mall fire which killed 19 including 13 children," The National, viewed 25 Jan 2016, Douglas, J 2006, Building Adaptation, Routledge, New York Embury, J 2012, “Examining Fire Safety in Shopping Malls," Fire Engineering, viewed 25 Jan 2015, Fang, L, Nielsen, P & Brohus, H 2007, Investigation on Smoke Movement and Smoke Control for Atrium in Green and Sustainable Building, viewed 17 Jan 2016, Fong, C 2008, "Fire Risk Factors In Shopping Malls," International Journal on Engineering Performance-Based Fire Codes vol 1 no 1, pp.p.21-28 Gollner, M, Kimball, A & Vecchiarelli, T 2012, "Fire Safety Design and Sustainable Buildings: Challenges and Opportunities Report of a National Symposium," National Fire Protection Association, viewed 25 Jan 2016, Hayward, J 2008, "Fire Safety in Shopping Malls & Premises Liability," Bentley College, reviewed 18 Jan 2016, < http://works.bepress.com/john_hayward/2/download/> Hossain, M & Suraya, S 2013, "Fire Safety At High-Rise Shopping Malls At Krol, M 2011, "Review of Smoke Management in Atrium," Architecture Civil Engineering Environment, pp.121-128 Lougheed, G 2000, "Basic Principles of Smoke Management for Atriums," Construction Technology Update No. 47 Morgan, H & Gardner, J 1991, Design principles for smoke ventilation in enclosed shopping centres, Construction Research Communications Ltd, London Nystedt, F 2011, Verifying Fire Safety Design in Sprinklered Buildings, Department of Fire Safety Engineering and Systems Safety Lund University, Lund Reikli, M 2012, The Key of Success in Shopping Centers. Composing Elements of Shopping Centers and their Strategic Fit, viewed 25 Jan 2016, Read More

Others include poisonous hydrogen cyanide as well as irritants like acrolein that disorientate individuals, thus hampering evacuation and rescue missions. Additional hazards include reduced oxygen levels, leading to suffocation. The high temperature from the fire is also potentially harmful to individuals immersed in smoke or exposed to radioactive materials. The reduce visibility due to smoke, hence hampering rescue and evacuation attempts (See Figure 1). Figure 1: Smoke hinders visibility 1.1.2 Smoke control in shopping complex According to Fang et al (2007), having knowledge of the fire movement inside a building is crucial in architectural design.

In their study of smoke control and movement in sustainable atrium buildings, Fang et al (2007) showed that smoke is the initial and utmost rapidly developed threat to human life during fire incidents in shopping complexes, where smoke bring about many problems. Smoke control is therefore a crucial set of practices for guaranteeing safety in shopping complex spaces. However, Colt (2007) emphasised that for smoke control to be effective, it has respond to the principles of smoke movement. This idea was earlier supported by Morgan and Gardner (1991), hence calling for a need for a review of the principles of smoke movement.

Following their examination of smoke movement in shopping centres, Morgan and Gardner (1991) explained that smoke emanating from a fire inside a unit shop within the shopping complex rises in a spiralling plume towards the ceiling. As the smoke rise, air joins the plume. This leads to reduced temperature and increased volume of smoke (See Figure 2). Figure 2: Typical smoke movement in malls (Colt 2015) Figure 3: Smoke and plume in a shopping complex fire (Lougheed 2000) Ultimately, the smoke outspreads below the ceiling in turn forming a layer that becomes deeper as the smoke fills into the shop (See Figure 4).

When the layer intensifies, the height by which the plume can rise lessens. Less amount of air becomes entrained leading to higher temperature on arrival at the smoke layer. Subsequent to this, the smoke flows out of the shop and further into the mall. The shift of direction of the flowing smoke leads to greater level of mixing with the surrounding air (Morgan and Gardner 1991). The degree of hot gases that carry the smoke particles is largely dependent on the rate and size of burning.

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