Technical Report

This is a summary of the report that responses to the call for an engineering solution on the implementation of a centralized home fire alarm device that would enhance the safety of residents living in a public housing residential estate. One problem identified was the absence of a centralized home fire alarm in all HDB. This problem is a risk that could potentially danger the lives of the residents in Singapore. 

There has been an increase in residential fire cases in the past few years. There were approximately 1,054 fire calls in residential premises and the majority of the percentage resulted from unattended cooking which was an increase of 5.9% from 2019 to 2020. In 2018, the government announced a mandatory implementation of a home fire alarm device in newly built residential housing that will alert people of the presence of smoke or fires. Installing a home fire alarm device played a huge role in ensuring the safety of residents within the building. A possible proposed solution that was researched could be implemented in both current and pre-built buildings. Thus, reducing the need for demolition or removal operations. The proposed solution is to install a Streamlined Fire Alarm Network (SFAN) with a reasonable size of Liquid Crystal Display (LCD) screen placed in each household unit. The SFAN would transmit data from every Home Fire Alarm Device (HFAD) in the residential block to a central network. The Streamlined Fire Alarm Network (SFAN) will be more appropriate to be installed in the electrical room while the LCD screen would be fixed along with the circuit breaker box where it is easily accessible and efficient to view in a case of fire. 

The implementation of SFAN would alert all residents and passers-by in the case of a fire outbreak within the building. It would quickly notify residents of early detection of fire. Thus, allowing them to evacuate the premises smoothly and safely. 

The importance of technologies is growing significantly and will prove beneficial in enhancing the living lifestyle, providing safety, and reducing the impact on the environment in the coming years. 

1.0 Introduction

This proposal has been developed in response to the request for developing solutions for an engineering problem. It aims to provide the Building Construction Authority and Home Development Branch with the improvements that could be made to the current Home Fire Alarm Detector that would enhance the safety in Singapore’s residential housing. 

1.1 Background

Singapore, a tiny country that is home to approximately about 5-6 million people, is also one of the most densely populated countries in the world. With that, public housing has become one of the special icons of Singapore. With more than 1 million flats across 24 towns and 3 estates, the Singapore brand of public housing is uniquely different compared to other countries (Housing Development Board (HDB), 2020). However, in recent years, fire outbreaks in these public homes are common and on the rise. As these public housing spells home to about 80% of Singapore’s resident population, it will be a major concern towards their safety within the flats (HDB, 2020).

For the past 2 years, there was an increase of 5.9% where fires broke out due to unattended cooking. These numbers would indeed in the long run affect the lives and wellbeing of the future and current families in Singapore. The people will be especially concerned with how their safety will fare in the near future. Over the past decade, about 70 percent of fire injuries have resulted from residential fires, compared to approximately 40 percent ten years ago (SCDF, 2017). Tighter safety measures need to be enforced to overcome such challenges. Thus, it is encouraged for Home Fire Alarm Device (HFAD) to be installed at units for better safety precaution in case a fire breaks out. It was the first step for Singapore to emphasize the importance of fire safety in public housing, catering to the safety and wellbeing of people.

In June 2017, a fire broke out at Grenfell Tower in North Kensington, West London. The report stated that an occupant, Behailu Kebde, described being woken by the sound of a smoke alarm and went into the kitchen and saw smoke in the area of the fridge-freezer near the kitchen window (BBC, 2019). Unfortunately, 72 people perished in the fire because they were not made aware of the fire incidents and evacuation procedures were not carried out quickly enough. This was mainly because of their naive policy of staying put even though there is a raging fire in the unit. Hence it is encouraged for stricter policies and better defense systems for quicker response to mitigate the underlying issue of this situation. This issue has always been overlooked and due to their ignorance, it has affected the lives of many

2.0  Literature Review

A smoke detector is a fire-protection device that detects smoke, a primary indicator of fire, and sounds an alarm to warn occupants of the building (IFSEC Global, n.d.). There are two kinds of smoke detectors, photoelectric (optical) and ionization (physical process). 

2.1 Photoelectric Smoke Detector

A photoelectric detector detects the sudden scattering of light when smoke enters the chamber, triggering an alarm. According to HopeCharlotte (2020), the alarm has a chamber that houses a light sensor, and inside the chamber, there is a LED light that projects a beam of light across the chamber. Compared to ionization smoke detectors, photoelectric smoke detectors respond 15 to 50 minutes faster to early smoldering fires, before they ignite (IFSEC Global, n.d.). This shows that a photoelectric detector has a high responsive sensitivity to fires that have a long period of smoldering.

2.2 Ionisation Smoke Detector

An ionization smoke detector works by ionizing the air between 2 electrodes which are positively and negatively charged, this creates a small current inside the chamber. This detector has chambers protected with insect screens to stop insects from entering and causing false alarms (Safelincs, n.d.). When smoke enters the ionization chamber through the opening vents, the balance of current in the ionization chamber will fluctuate due to the particles in the smoke. Once sufficient smoke has entered the ionization chamber, the fluctuation in current will trigger a signal to be sent to a circuit and cause the alarm to sound. This will alert the occupants of the fire. Commonly Ionisation smoke detectors are situated on landings (Safelincs, n.d.). This is because situating at areas close to the kitchen will more likely trigger a false alarm.

2.3 Photoelectric vs Ionisation

Both detectors work well against fire, Ionisation detector is best used when detecting rapid flame fires whereas photoelectric detectors are best at protecting against slower, smoldering fires. Although both detectors have their own advantages, photoelectric detectors outperform ionization detectors when it comes to residential fire (First Alert, n.d.). Whenever a fire breaks out, it is best to detect an early sign of fire which is smoke. Heat detectors can be useful only if the speed of detecting smoke and fire is not critical, or if the space is limited and fires are likely to burn fast. These scenarios, however, do not lend themselves to residential fire protection (Vivint, 2018). Thus, detecting early signs of smoke is the most reliable way to safeguard your home against fire. 

2.4 Centralized System

The concept of a centralized system connects all users to one network or server. The server will then receive all data from every user and store them respectively. It is easy to build and can be developed quickly. However, there is a downside to this system. In the case of a server crash, the system stops working properly and data cannot be accessed by users. In the case of a server crash, the system stops working properly and data cannot be accessed by users. Since centralized systems require a central server to connect all users and devices. This server determines the network's availability (Touron, 2019). Despite its limitations, it is practical and to have a central system as it can control multiple users at once. Also, with disciplined maintenance and servicing, we can avoid having faults in the user network/system.

3.0  Home Fire Alarm Device (HFAD)

According to SCDF (2021), HFAD has been implemented by the Singapore Civil Defence Force in new residential buildings in every household unit. Its main purpose is to detect whenever there is fire and will alert everyone in the unit with its built-in alarm. This is a useful device as it gives ample time for occupants to evacuate the building by giving an early warning. Although it is to detect fire, the device actually detects smoke as it is much more effective in providing early warning of fire compared to a heat detector. Furthermore, HFADs have an operational lifespan of a decade, and it is a wireless device that is convenient for users. However, HFAD is not mandatory in existing residential premises, but existing homeowners are strongly encouraged to install HFADs in an effort to protect themselves (SCDF, 2019). Ideally, each household owner needs at least 1 HFAD installed in their home. It is also up to the owners of the house on how many HFADs to install since there are no limits to it, however, it can be costly to purchase and install one. The location to install an HFAD is the most crucial part, there will be a chance where it will emit a false alarm due to its proximity range. For example, HFAD should not be placed anywhere near a cooking area or burning religious paraphernalia. Instead, it is advisable to place it along with a corridor or ideally, the living room. 

Figure 3.1
The external appearance of the HFAD

Note. Adapted from NINGBO SITERWELL ELECTRONICS CO., LTD (2016),

Smoke Alarm User’s Manual (schrackcdn.com)

Figure 3.2
Detailed prototype parts 

Note. Adapted from NINGBO SITERWELL ELECTRONICS CO., LTD (2016),

Smoke Alarm User’s Manual (schrackcdn.com)

4.0  Problem statement

Ideally, every building in Singapore should require a centralized HFAD system to be installed to allow not only every occupant in the building to be alerted in case of fire but also any other persons on the premises. However, Not every building has implemented a centralized HFAD system. Therefore, some building occupants within the building may not be aware if a fire breaks out in one of the units due to activities such as listening to music. Installing the Streamline Fire Alarm Network system that links all HFAD in every unit within the building will give every person in the building ample time to evacuate the building. 

5.0  Purpose statement

The purpose of this report is to propose to the Housing Development Board (HDB) and Building Construction Authority (BCA), who is responsible for public housing, to implement a centralized HFAD system in all HDB buildings for enhanced and stronger safety for the residents in Singapore.  

6.0 Proposed solution: Modification or innovation

The proposed solution is to create a centralized system, Streamline Fire Alarm Network (SFAN), linking all the HFAD installed in all units within the public housing. The SFAN allows not every occupant in the unit but also every other occupant in the building.  This modification will improve the response of an evacuation in case of fire outbreaks. The improvement of the response will allow occupants to react faster to emergencies as the SFAN is triggered. According to the Professional Evaluation and Evaluation Board (2014), ‘Having a centralized system creates consistency, reduces risk and increases profitability, improves internal and external communication’. Other Occupants in the building may not be aware of a fire outbreak in a certain unit, and to close this gap, a centralized system will alert everybody around the building premises in case of a fire outbreak.

Figure 6.1

HFAD System

Note. Adapted from Nanyang Technological University Singapore (n.d.),

Research Capabilities | Smart Nation Translational Lab (SNTL)​ | NTU Singapore

From Figure 6.1, we can understand that whenever a fire breaks out, it will trigger the HFAD which will then activate the alarm in the house. It will then transmit a signal to the sensor hub. A sensor hub is a device that connects multiple sensors and compiles and processes data gathered from those sensors with a multipoint control unit (MCU), coprocessor, or digital signal processor (DSP) (TechTarget, 2015). It will then transmit data to the DECADA cloud whereby device management, data collection, and data analysis for Internet of Things (IoT) devices are provided (SIOT, 2021). After the cloud has finished processing, it will inform the necessary parties to take action, for example, the SCDF and other response teams. 

From the figure below, the SFAN will gather all information from all the HFAD sensors in the building. With the information it received, in the case of a fire breaking out, it would send out signals to every sensor and discharge sound signals located around the building to warn people of fire. They would also automatically send requests to SCDF for emergency response. Only relevant authorities would be allowed to gain access and information from the SFAN. Analytic data and information would help in conducting further measures to prevent any fire hazard. On top of that, there will be an LCD screen installed in each unit to prompt the occupants on which unit and floor the fire is at. This will assist the occupants to plan which escape route to take that is suitable for their safety. 

Note. Designed by our team

7.0 Benefits 

7.1 Easy installations

Installation is a straightforward process since SCDF assists in listing retailers and suppliers that provide fire safety systems. By facilitating this, occupants will be encouraged to have HFADs installed in their homes. HFADs are relatively inexpensive since they are able to last up to 10 years and do not require replacement batteries. Residents can decide where HFAD sensors should be placed in their residences and only need to conduct maintenance once a month. 

7.2 Increase safety

By installing HFAD sensors in residential units and buildings, it can assist in managing fire hazards. A fire hazard can be detected and prevented by detecting early signs of smoke. Located around the building, alarms and sirens will generate sound signals that will alert people to evacuate if a fire occurs. Occupants will have peace of mind knowing that Streamlined Fire Alarm Network provides surveillance throughout the day when they are away from their house or sleeping at night. 

7.3 Gather information 

SFAN units will provide relevant authorities with the information they need to do any follow-up on units that have triggered any alarm. This would also provide useful information for SCDF to conduct studies on areas or buildings that could pose fire hazards. 

8.0 Evaluation/Limitations

The main obstacles of having a centralized system are a fault in the system, misuse of the HFAD, and security.

8.1 System Fault

In some cases, a single point of failure can influence the whole system to function as intended (N-Able, 2018). For example, there is a fire broke out in unit A, the HFAD will activate and send a signal to the centralized HFAD, and if a handful HFADs does not seem to work due to fault in its devices, those HFAD would not be able to receive any information from the centralized HFAD. Hence, it will increase the risk of safety for the occupants in those units.

8.2 Misuse of HFAD

Another downside is that many individuals are capable of accessing the system to satisfy their needs which, therefore, will impact the performance of the system (McGew, n.d.). In an event where kids are curious and meddle with the HFAD, not only will there be a false alarm in their own unit but the whole premises will be affected as well. This will in turn give all the occupants a false hope on the centralized HFAD system.

8.3 Security

According to McGew (n.d.), having a centralized system makes itself a vulnerable target. Regardless of how tight the safety measures are to protect its network, a centralized system only makes it more endangered. Fire may be the act of terrorism, and the terrorist may sabotage and destroy the SFAN which destroys the whole system of alerting the occupants in the premises. Hence, the lack of security may lead to a major downfall of the system.

9.0 Methods / Procedure 

This report was constructed using a variety of secondary resources. The team chose to source significant and relevant information through secondary research on different types of detectors that could be used in residential housing. The information that we gathered is mainly from SCDF websites. We gathered related information on the implementation and regulations of HFAD in Singapore residential housing to further improve the current model system. 

10.0 Conclusion

As fire outbreaks in residential housing continue to grow, and the number of public residential housing in Singapore increases. This report provides an innovative engineering configuration to the Home Development Branch (HDB) and Building Construction Authority (BCA) to connect all HFAD sensors in a single unit to a centralized home fire defense system in a residential block. In the event that there is a fire within the residential block, an alert sound signal will be sent to neighbors and passersby around the area. Evacuation processes will be streamlined and safety will be enhanced. Authorities can also regularly check data analysis stored in the centralized fire alarm system if there is any sensor triggered due to false alarms or incidents that occur, so they can take appropriate action. 

It should be evident from this report that incorporating a centralized fire home defense system in public housing will enhance safety measures during a fire outbreak and prevent undesirable events. 

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