The stairs are the one and only safe way to exit during a fire in a high-rise building. When there is a fire, it's essential to make an exit clear for safe evacuation. To make the stairs smoke-free and ready for a safe exit, it's essential to incorporate electro-mechanical design features. Nowadays, in every country, the building codes require stairwells with vast space and a stair pressurisation system in high-rise buildings. The stairs pressurisation system reduces the smoke in the fire exit area when a fire occurs. The system stops the migration of smoke from the floor to the stairwells, refuge areas, elevator shafts, or similar sites. It maintains a smoke-free, secure, and inhalable environment during the time evacuation is in progress. It gives the firefighters easy access to the fireplace and performs rescue operations by improving visibility in the building. This project demonstrates the most efficient IoT-based fire stair pressurisation system with a fire alarm and notification facility.
Introduction
High-rise construction density on very valuable real estate is very frequent these days. High-rise buildings provide a problem in terms of fire safety. High-rise buildings present a challenge from a fire safety perspective. They are often taller than the fire department ladder trucks can reach for rescue operations, and they require additional time for evacuation due to the height of the building. High-rise buildings require protected exit stairwells for evacuation during an emergency. Due to the additional egress time, the building and fire codes require additional protection for exit stairwells in high-rise buildings. Along with the standard smoke control system suggested by the International Building Code (IBC), there should be an IoT-based alarm and control system to take immediate action in the event of a fire to reduce casualties and damage.
Our project aims to make an IoT-based Fire Stair Pressurization System and a fire alarm system to let the right people know what's happening.
Literature Review
IoT is the concept that creates a relationship between users and systems remotely. It also facilitates device connectivity. The Internet of Things has three C's: cost savings, control and automation, and communication [1].
We've tried to add IoT to a system like this so that users can manage and interact with it on a tight budget. By employing cloud platforms, the user may also keep an eye on the surroundings.
With its low-cost effectiveness, the Wi-Fi Module can be very helpful and straightforward to use when connecting to the internet.
A user may monitor, receive notifications, and take instant action using the internet.
The low-cost, very powerful system-on-a-cheap (S0C) microcontroller [2] has wifi facilities built-in to build powerful IoT devices with high accuracy, reliability, and robustness features.
The cloud server for this project is Node-RED [3], one of the most compelling IoT tools.
Component Requirements
Various parts were used to complete the system's functionality. The ESP32 microcontroller, DS18b20 temperature sensor, MQ-2 gas and smoke sensor, DHT22 humidity sensor, liquid crystal display (LCD), DC pump, cooling fan, relay module, jumper wires, and a 12-volt power source are some significant parts used in this system.
The ESP32 was programmed using the "AVR C" language in the Arduino IDE to handle and manage various logical statements to process inputs and obtain outputs.
System Development
The high-rise building model was built using PVC board with the help of glue and acrylic. The ESP32 was programmed using the open-source Arduino platform. The system can be monitored both offline and online. The ESP32 Wi-Fi has been used to enable IoT, and because of internet downtime, the GSM module has been used for uninterrupted communication.
In both ways, the ESP32 sends data using the MQTT protocol to the cloud server. The server is based on Node-RED, a low-code platform by IBM with amazing IoT features. The server stores the information needed to make different reports and runs the alarm system.
The ESP32 can trigger alarms and start the pressurisation system independently, so there is no delay in a fire situation. At the same time, it sends data to the cloud with an alarm message and an SMS to the assigned user. If there is a fire situation, the node-RED server sends an alarm message to the internet platform users and a telegram group. There could be multiple support people in the group from multiple places.
Block Diagram
The following figure shows the data flow diagrams of the project.
Fig. 1 A sample data flow diagram of the system
Pressurization Technique
High-rise apartment buildings can use a variety of stairwell smoke control system designs, including non-compensated, compensated, single-injection, and multiple-injection pressurisation methods. Any technique can incorporate IoT technology to make it automated.
Two types of fans can be used for stair pressurisation systems: axial fans and centrifugal fans. The IoT-based solution can control any type of AC fan using magnetic conductors, relays, or any other electromagnetic switch.
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| Fig. 2 Axial fans (left), with their intake and outlet airflow pointing in the same direction (blue arrows), and centrifugal fans (right), with their inlet and outlet airflow pointing in opposite directions. |
Cloud Platform
The user interface and the cloud server have been implemented using the Node-RED platform.
The platform is IoT-friendly and straightforward to use, with little coding knowledge. The platform is built on the potent programming language Node.js. A float graph representing the history of the data is displayed on the screen, along with real-time data from the system in the responsive user interface.
The maintenance of two-way communication between the messaging application Telegram and the internet user is one of the most significant tasks handled by the node-RED service.
Fig. 1 Example of temperature data in Node-RED Dashboard
Massaging app
The IoT system users' Telegram group is seen in Fig. 3. The messenger was the Telegram bot. The bot interacts with the Node-RED platform and answers the request accordingly.
Fig. 3 Messaging app (Telegram) Group
Various Inputs
There are many options, particularly for receiving input. By using their approved user accounts, cloud users can send any query and receive an ESP32 response in response to their request.
Users of the messaging app can also ask the ESP32 for environmental information like the current temperature, humidity, gas pressure, and alert status.
By sending certain phrases to a specific SIM number inserted into the SIM800L GSM module, offline users can obtain the current system status.
The shortcodes and the system responses are mentioned in the following table.
TABLE 1
Short Keywords for SMS Alert
Additionally, the ESP32 continuously reads the sensors and sends the data to the server at predetermined intervals.
Various Outputs
The system analyses the sensor data, generates the alarms, and displays various states as an outcome. Additionally, the system sends brief messages (SMS) to a set of people, including the manager, the fire station, and the building owner.
This is an independent method of sending messages without the internet.
Electrical Circuit
The ESP32 periodically retrieves data from sensors and shows it on the 16X2 LCD screen.
Thanks to the ESP32's built-in solid Wi-Fi, it also transfers the data to the server utilising the internet and the MQTT protocol. By examining data from temperature, humidity, and gas sensors, the ESP32 generates an alarm.
Fig. 2 Circuit diagram of esp32, display, and sensors
When an alert goes out, the ESP32 promptly tells its users through SMS, mobile app, web panel, and telegram user group to the individuals who need to know and the fire station along with locating the fire source.
Fig. 3 Circuit diagram of ESP32, SIM800L GSM module
An automatic fire stair pressurisation system is also activated simultaneously to reduce smoke deposition in the stairs and facilitate quick escape during a fire.
Fig. 4 Circuit diagram of esp32, fan, and sensors
Final Prototype Design
Fig. 5 shows the final design of the project. The prototype model represents a high-rise building. The model has an IoT-based stair pressurisation system that works perfectly with an advanced alarm system.
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Fig. 5 Final project demo design with IoT-based fire stair pressurisation system |
Future Scope
One of the downsides of the IoT alarm system is the power backup so far. This problem can be solved shortly. Generally, if there is a fire, the electricity is gone. The fire stair pressurisation system needs its own power source and a separate network for the Internet of Things devices. so that the user can be kept up-to-date about the fire situation.