Evaluation of Fire Safety Problems in Energy-Efficient Buildings

*Sevinç Çetin and Figen Beyhan* 

#### **Abstract**

For the last 40 years, the concept of sustainability which has busied the world agenda has also affected the building sector, and in the built environment, design approaches have emerged that aim to bring solutions to many problems, especially energy. These approaches, which are supported by the legislations and the incentives provided by the country policies, have also changed the characteristic of the constructed buildings. In accordance with the intended objectives, these buildings have many positive qualities, and it is significant to consider other risks based on construction and design features in terms of sustainability. The most important of these risks are fire and fire threat increasing with the architectural design or application details. The aim of this study, which deals with this risk as a problem, is to examine fire safety in buildings constructed with energy-efficient construction principles and techniques and to investigate the ignition, spread, and control of the fire. The performance-based design approach, which can be applied in the cases that the fire safety measures restrict the design and have application difficulties, will be examined.

**Keywords:** fire, fire safety, fire risk, energy, energy-efficient building

#### **1. Introduction**

Energy performance has become the important criterion in construction in the last decade [1]. However, this is not the only criterion to be considered in the design of buildings, but one among several others such as cost, space usage, accessibility, human comfort, structural design, or fire safety. Indeed, design of the buildings can be conceived as a multipurpose concern in which a global optimum is aimed in relation to the combination of each of the considered criteria. The use of multiobjective optimization techniques requires the application of quantitative analyses in which an objective or target function can be "measured." This sets the baseline for performance-based designs, which require quantifiable variables to be applied [2].

 Designers have concerns about the use of some design features used in energyefficient buildings, as they impact the building fire safety. For example, atriums are an important design feature for providing natural light, but it is considered as a hazard as it increases fire and smoke spread. Also, high ceilings can affect fire sprinkler success. Further, the lightweight structure can reduce the structure strength, and when a fire occurs, it collapses quickly [3].

In this study, the general benefits are achieved from energy-efficient building design features. Atrium, double-skin facade, photovoltaic panels, insulation and materials, HVAC systems, skylights and solar tubes, high-volume/low-speed

 (HVLS) fans, and natural ventilation were outlined. Their potential fire risks were highlighted. Performance-based fire safety design approach and fire safety measures for these features were suggested to be updated.

#### **2. Design features of energy-efficient buildings and fire risks**

In this study, the following framework is developed for defining the energyefficient building features and their fire risks (**Figure 1**):


#### **2.1 Double-skin facades**

A double-skin facade system can be formed over a whole facade or just a portion of it. It can be applied to all kinds of buildings. It can be installed to any existing building with minimum adjustments. The double-skin facade system is composed of three components: an outer skin, a ventilated space, and an inner skin. The double-skin facade system has many advantages. One of the main advantages is to reduce the energy used by buildings. It allows natural daylight into a building for lighting, reducing the heat load. It also helps to reduce the acoustic effect in a building. The double-skin facade spaces may reduce solar heat gain and support heating, ventilation, and air conditioning (HVAC) systems [4]. However, the structure of double-skin facade system can increase the fire risk as shown in **Figure 2** [5]. Smoke movement may cause glass damage on double-skin facade, and this is the one reason of fire spreading in buildings with double-skin facade [6, 7].

**Figure 1.**  *Framework of the study.* 

*Evaluation of Fire Safety Problems in Energy-Efficient Buildings DOI: http://dx.doi.org/10.5772/intechopen.87836* 

In the case of a double-skin facade, the spreading of a fire along a facade, the evacuation of the occupants, and the action of the fire fighters should be carefully examined [6]. To summarize, designers should take into account the fire risks mentioned in **Figure 3** for fire safety of double-skin facades.

#### **2.2 Insulation and materials**

Insulation is considered one of the effective solutions to achieve saving energy in buildings. While the use of insulating materials in buildings has resulted in energy conservation, this use has also created fire risks. For example, some insulating materials can contribute to the spread of a fire, while others produce smoke and toxic gases. The amount of insulation in the walls and ceiling/roof of a room can affect the rate of growth of a fire. Insulation will reduce heat transfer to other areas (i.e., rooms), thereby raising the temperature in the fire room. Higher temperatures in the fire room will accelerate the burning of materials in the room, resulting in an

#### **Figure 2.**

*Migration of the fire through a double-skin facade [5].* 

**Figure 3.**  *Fire risks/hazards of double-skin facades.* 

 increase in the heat released into the room. The greater the amount of insulation, the higher the temperature the fire in the room can be expected to reach. Insulation may also affect the performance of heat-producing devices, such as electrical wires, cables, and electrical fixtures. Insulation installed around the heat-producing device can cause the device to become overheated; if the device becomes hot enough, it can ignite combustible materials in contact with it. Insulating materials may have an adverse health effect when they are handled or exposed to fire. Fires in insulation materials can result in the release of toxic gases and smoke, which can be fatal if present in sufficient quantities. Smoke can create problems for occupants trying to evacuate the fire area. When some materials, such as fibrous glass, are handled, occupants and others who contact it may experience skin irritation [3]. There are a lot of fires that have occurred or spread because of insulation materials, including the 2009 Monte Carlo fire in Las Vegas and the GOP Taksim Training and Research Hospital in Istanbul in 2018. These past events show that designers should be more careful about the use of insulation materials on facades of the buildings. To summarize, designers should consider the fire risks mentioned in **Figure 4** for fire safety of insulation and materials.

#### **2.3 Atriums**

Atrium is defined as two or more high gaps, consisting of a large and vertical volume surrounded by a closed and surrounded area. There are many advantages in having an atrium. With an appropriate design of glazed area of the atrium, heat transfer through atrium can benefit the thermal comfort of the internal occupied space. Utilizing daylight would provide better visual quality and reduce the energy use on operating artificial lighting. Investment return can be also benefited from its environmental performance and favorable appearance. Atriums may be surrounded with glazing or open to some or all floors. However, fire hazards are associated with this character. The space spanning several floors would become an effective means for the spread of smoke in an event of a fire as illustrated in **Figure 5** [8]. An atrium prevents dividing the floors of a building with fire cells, so all atriums allow fire spread between floors. An open atrium allows the passage of smoke between floors and may reduce the amount of time occupants that have to escape from upper floors. The rapid spreading of heat and toxic gases can cause life losses, human injuries, and property damage [8]. A glazed atrium may allow fire to spread between floors if the glazing breaks down in an uncontrolled fire [9].

**Figure 4.**  *Fire risks/hazards of insulation and materials.* 

*Evaluation of Fire Safety Problems in Energy-Efficient Buildings DOI: http://dx.doi.org/10.5772/intechopen.87836* 

Spread of smoke is the most important concern in an atrium. Fire safety sprinkler system, smoke curtain, and fire shutter could be installed for this special building type. Other fire safety measures are smoke extraction system and depressurization of an atrium space. Staircase pressurization system is efficient in providing a smokeless escape route. When it is worked, pressure in the stairwell is provided at a level higher than that in the atrium or other occupied spaces by supplying a large quantity of air. Thereby smoke in a fire compartment of low pressure would not move toward the escape route of high pressure [8]. To summarize, designers should take into account the fire risks mentioned in **Figure 6** for fire safety of atriums.

#### **2.4 Natural ventilation**

Natural ventilation of buildings is more favorable in terms of energy conservation, economy, and health than other mechanical systems. However, the ability to ventilate the building at the desired level by natural methods requires the following: appropriate external air is reached to the building, this air is taken into the building through the building shell, sufficient and appropriate air circulation in the building is ensured, and the contaminated air is taken out of the building.

Air moves from the high-pressure (positive) zone to the low-pressure (negative) zone. Velocity of the air movement, distribution of pressure zones in and around the building, and pressure levels are important in providing the desired level of ventilation with natural methods.

#### **Figure 5.**

*Fire and smoke spreading in atriums [8]. (a) Fire at the atrium floor. (b) Fire at an adjacent space.* 

**Figure 6.**  *Fire risks/hazards of atriums.* 

Natural ventilation provided in a building can create serious problems in terms of fire safety. Stack effect is a way to provide natural ventilation. The heat rising from a fire in a compartment will attract fresh air at rising speeds; it will contribute to the growth and spread of the fire [10]. In a building with a good natural ventilation, there are many vertical transitions and horizontal connection areas. For this reason, designs with natural ventilation sometimes conflict with fire safety measures (especially when designers consider passive safety design for the buildings) [11]. To summarize, designers should take into account the fire risks mentioned in **Figure 7** for fire safety of natural ventilation.

#### **2.5 HVAC systems**

The HVAC system is the technology to provide thermal comfort and acceptable indoor air quality. HVAC is an important part of buildings especially hotels, skyscrapers, hospitals, etc. It controls the temperature and humidity, using fresh air from outdoors. During a fire, the time is important for occupant evacuation. HVAC systems can be used to control/slow down smoke propagation on the fire floor. Providing fresh air to the route of the evacuation is important to prevent the occupants from breathing into the poison gases. HVAC systems can control smoke conditions and heat change; therefore it is possible to make the building safe in the event of the fire by using the HVAC operations [12]. It should be noted that the effect of HVAC systems on the fire safety of the buildings has not been much researched.

Fire and smoke compartments are made up in the buildings in order to prevent spreading of fire and smoke during a fire. Fire compartments consist of walls and ceiling, and so each must have the necessary resistance of fire. The ventilation channels of HVAC systems go through walls and ceilings and make the building unsafe from fire. Fire protection must therefore be provided with other measures. When a fire damper is used as shown in **Figure 8**, ventilation channels are isolated when a fire occurs [13]. Studies conducted by NFPA in 1930 showed that to prevent the passage of smoke, flame, and heat during a fire, dampers must be used in the HVAC system [14].

To summarize, designers should take into account the fire risks mentioned in **Figure 9** for fire safety of HVAC systems.

#### **2.6 Photovoltaic solar systems**

Photovoltaic solar energy systems can be defined as panels for generating electricity from solar energy. Nowadays, it is one of the most important issues on developed countries because photovoltaic solar systems reduce energy use significantly and important cost savings in electricity consumption [3]. However, photovoltaic

**Figure 7.**  *Fire risks/hazards of natural ventilation.* 

*Evaluation of Fire Safety Problems in Energy-Efficient Buildings DOI: http://dx.doi.org/10.5772/intechopen.87836* 

#### **Figure 8.**

*Fire dampers help to prevent fire and smoke from spreading [13]. (a) Spreading of fire and smoke through ventilation channels. (b) Protected by fire dampers.* 

#### **Figure 9.**  *Fire risks/hazards of HVAC systems.*

 solar systems can cause fire hazards. The most likely cause of solar-related fires is due to electrical component failures associated with photovoltaic solar system installations [15]. Target store fire in Bakersfield (2009) and a logistic company's warehouse fire in Burstadt (2009) are the larger rooftop fires that start on photovoltaic solar panels and have gained a lot of attention [16]. During a fire, the risks associated with photovoltaic solar system increase. If the photovoltaic solar system is on fire and firefighters are attempting to extinguish the fire with a hose stream of water, the energized panels can electrify the stream of water. This can result in firefighters possibly being electrocuted. To avoid this risk, firefighters can apply the stream of water at a safe [15]. Finally, the presence of photovoltaic solar systems on rooftops can increase the probability of a roof fire because of the problems with components such as wiring to install photovoltaic solar system. In addition, when a fire occurs, the presence of a photovoltaic solar system may increase the size of the fire. Designers should take into account the fire risks mentioned in **Figure 10** for fire safety of photovoltaic panels.

#### **2.7 Skylights and solar tubes**

 Skylights/solar tubes and daylight natural lighting systems contribute to the economy of both users and countries by carrying daylight to places with zero energy. Skylights/solar tubes minimize the need for the use of electric lighting systems (artificial lighting) during daylight hours and provide lighting using daylight. Skylights/solar tubes, which provide natural lighting with zero energy, are nature-friendly and prevent carbon dioxide emissions. Skylights/solar tubes also make a significant contribution to our quality of life as psychological and physiological [17]. Solar tube passes through a roof space and other spaces. These

 joints and openings are the weakest points of roofs and fire compartments whose essential function is to prevent fire from spreading across the building. These unprotected vertical openings allow migration of fire and smoke [18]. Designers should take into account the fire risks mentioned in **Figure 11** for fire safety of skylights/solar tubes.

#### **2.8 HVLS fans**

High-volume/low-speed fans are designed to provide energy savings by mixing the air throughout the space [17]. They were developed to increase occupant comfort cost effectively or prevent stratification. With these fans, the air slowly circulates a large amount. The air is pulled from above with the fan and pushed down in the cone shape. Typical applications include industrial and commercial buildings such as shopping centers, office buildings, fitness centers, and schools. When they are applied in industrial and large buildings, it can be highly economical. But HVLS fans can cause a lot of fire concerns. So, designers must take into account fire measures about HVLS fans at the design stage of the buildings [17].

 The National Fire Protection Research Foundation has studied the effects of HVLS fans on fires in buildings [18]. According to the National Fire Protection Research Foundation, sprinkler effectiveness is reduced in buildings with HVLS fans, and the fans need to stop upon early fire detection before or on the activation of fire sprinklers to reduce the impact on fire spread. With HVLS fans activation of smoke detection systems is also negatively impacted so designers should consider this feature of HVLS fans when designing these systems [19]. As a result, designers should take into account the fire risks mentioned in **Figure 12**  for fire safety of HVLS fans.

**Figure 11.**  *Fire risks/hazards of skylights/solar tubes.* 

*Evaluation of Fire Safety Problems in Energy-Efficient Buildings DOI: http://dx.doi.org/10.5772/intechopen.87836* 

**Figure 12.**  *Fire risks/hazards of HVLS fans.* 

#### **3. Necessity of performance-based fire safety design**

Fire protection measures have generally been implemented through building codes and standards in the form of regulations listing various requirements and have been developed over the years as new requirements have been added to existing ones. Building regulations, in other words, prescriptive codes evolved over the last century, have been continuing to be the primary means to determine the acceptable building fire safety level. However, such codes are limited and inadequate to evaluate the fire safety performance of fast-growing building technologies and innovative designs [20]. The necessity for architects to change their design decisions in a way that adapts to traditional codes causes code requirements to be perceived as design constraints. In the 1980s this concern led to the development of a flexible fire safety design method based on engineering calculation methods as an alternative approach to traditional approach, and functional and performance-based approach has emerged for building and fire regulations. Although this new approach has not yet been developed in our country, significant progress has been made in countries such as Japan, Canada, America, and the United Kingdom.

Performance-based fire safety design is the engineering approach for fire safety design based on a numerical evaluation of design alternatives using agreed engineering tools, methods, and performance criteria, based on determined fire safety objectives and deterministic and probabilistic analysis of fire scenarios [21]. Performance-based fire safety design involves the transformation of functional and technical requirements in the early stages of design into performance requirements and design in accordance with these performance requirements. Performance evaluation of the design is done by using some methods (simulation tools, calculations, measurement methods, etc.) These assessments are made to check whether the expected performance of the building has been met, whether the accuracy of the design results, and whether the desired performance goals are met [21]. The process of performance-based fire safety design starts with determining the scope, goals, and objectives of the project, establishing performance criteria, developing design fire scenarios, creating preliminary designs, quantifying design fire scenarios, and evaluating the compliance of preliminary designs with performance criteria. If the evaluated design does not meet the performance criteria, it is returned to the beginning of the process. If the design complies with the performance criteria, the final design phase is started (**Figure 13**).

#### **Figure 13.**

*Performance-based fire safety design process [21].* 

#### **4. Conclusion**

 The fire industry has concerns about the use of new and innovative technologies in energy-efficient buildings. Because energy-efficient building design features such as complex indoor vertical spaces, double-skin facades, natural ventilation, and high atriums increase the fire risks. In cases where fire cannot be controlled, it can cause great loss of life and property and may cause loss of production/work interruption and undesired effects on the environment. A performance-based fire safety design approach is recommended for conflicts between energy-efficient buildings and fire safety has been suggested.

There is a worldwide movement from prescription-based to performance-based fire codes so as to suitably address the new fire safety building design in our everchanging living environment. Yet, there are some difficulties in the application of performance-based fire safety codes. The most essential one is how performance criteria should be determined. These criteria include life safety of the occupant and fire fighters, fire and smoke hazards, etc. Furthermore, there are still studies for improving the accuracy of those field models, especially validation of the models.

 In this study, fire risks of the energy-efficient building design features are pointed out, and for the solution performance, base design is suggested. The reason for suggesting the performance-based approach in fire safety is the expectation that the designer will gain advantages such as being more flexible in design and decrease the construction cost especially in energy-efficient buildings. Especially while fire scenarios are being developed, the fire risks of these buildings will be anticipated so the measures will be taken in the design stage.

*Evaluation of Fire Safety Problems in Energy-Efficient Buildings DOI: http://dx.doi.org/10.5772/intechopen.87836* 

#### **Author details**

Sevinç Çetin1 \* and Figen Beyhan<sup>2</sup>

1 Project Department, Ministry of Health, Ankara, Turkey

2 Department of Architecture, Gazi University, Ankara, Turkey

\*Address all correspondence to: sevinc\_ari@hotmail.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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*Evaluation of Fire Safety Problems in Energy-Efficient Buildings DOI: http://dx.doi.org/10.5772/intechopen.87836* 

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**835**

**Chapter 67**

Sources

**Abstract**

**1. Introduction**

*and Sajjad Sayyar Roudsari*

Fire Performance of Sustainable

Materials Made from Renewable

This paper presents the results of a fire test on newly developed green materials made from renewable sources. It is known that fire resistance rating of a new material is an important factor for material selection in buildings. The fire resistance rating of structures, building components, or assemblies needs to be predicted experimentally in agreement with the ASME E119 or UL 263 test procedures. The material tested is a drywall partition system composed of 9 mm-thick MgO board as the first layer on both sides and 9 mm-thick patented bamboo plyboard as the finishes. The internal steel frame is comprised of steel stud C channel fixed to the RSJ steel frame. The first layer of 9 mm-thick MgO board was laid horizontally over the wall frame on both sides and fastened to the studs with screws. The test was stopped after a duration of 120 minutes. The purpose of the test is to determine the fire resistance of non-load-bearing drywall panel partition system when tested. This paper describes the outstanding results related to the specimen performance under the fire conditions. The results exceed the specified requirements of Clause 5 of BS 476: Part 22, for non-bearing wall, in terms of integrity and insulation.

**Keywords:** safety, fire protection, fire resistance, test process, insulation, integrity

Building components need to have resistance to prevent excessive heat transfer, noise, as well as the fire spread and smoke dispersion for a period of time to allow the inhabitant to leave the building without casualty. Fire resistance is a component characteristic that evaluates the building unit's performance to survive and preserve its structure and operation and/or its aptitude to bound fire in a definite space [1–3]. In general, fire resistance helps to prevent a fire from spreading throughout a building or jumping between structures. In this paper, an experimental study was performed for a system, data analysis, and test monitoring, based on a standard for evaluating fire performance. This performance is assessed by the fire durability time for the fire resistance test, to protect the building from the multiple risks and losses caused by fire [2, 3]. To control the spread of fire, fire protection methods are divided into active ones, such as sprinklers and passive ones, such as fire resistance, both of which are incorporated into building codes. The building codes include a variety of prescriptions as well as alternative solutions. Code tendencies generally

*Sameer Hamoush, Ahmed Cherif Megri, Rasul Pasha* 

#### **Chapter 67**
