The article delves into the ventilation and smoke exhaust system design for the new energy bus parking garage on Xietu Road, Shanghai. Located within a high-rise urban complex, the project addresses the unique challenges of housing electric buses by optimizing space, enhancing fire safety, and ensuring energy-efficient operations. Key considerations include noise reduction, air quality management, and automated fire response systems, making this facility both environmentally conscious and technologically advanced. Discover how innovative engineering meets this cutting-edge transport infrastructure’s strict urban environmental and safety standards.
01 Design Background and Objectives
The Shanghai International Medical Science and Technology Innovation Center, home to the Shanghai Xietu Road Electric Bus Depot, represents a pioneering effort in urban infrastructure—an advanced multi-story parking facility for electric buses nestled in the heart of the city. This project not only addresses the pressing need for efficient public transport solutions but also integrates essential safety and environmental considerations.
In developing the exhaust and smoke management systems, as well as the fresh air intake and distribution mechanisms, we recognized the imperative to optimize the garage’s capacity for housing a growing fleet of electric buses. To maximize space, the design avoids subdividing the structure into separate fire protection units. The ventilation system is equipped with both manual and timed automatic control capabilities, while the smoke exhaust system features automatic or manual activation. Given the garage’s central urban location, noise mitigation strategies are paramount. Therefore, we selected low-noise, energy-efficient fan systems, ensuring operations can be automated to further enhance energy savings. Let’s delve into the critical considerations that guided this project.
02 Design Principles and Considerations
Ventilation: Discharging Waste Heat and Exhaust Gas
The primary goal of the ventilation system within the electric bus parking garage is to efficiently expel harmful waste heat and exhaust gases produced by charging facilities, batteries, and charging cables during operation. Adhering to industry standards, we established that the working environment temperature for electrical equipment should not exceed 40°C. To ensure safety and optimal performance, our design incorporates a ventilation system with a minimum frequency of six air changes per hour, effectively managing the thermal load and maintaining a hygienic environment.
Smoke Exhaust: Safeguarding Against Toxic Emissions
In the unfortunate event of a fire—particularly during the charging process of an electric vehicle—the combustion of electrical components and cables can generate toxic smoke, complicating rescue operations. Traditional dry powder extinguishers are often inadequate for such fires, underscoring the need for robust preventive measures. Our design not only includes an automatic fire alarm system and emergency lighting but also integrates a smoke exhaust system that activates in conjunction with fire detection systems. This ensures rapid evacuation and minimizes the risks associated with toxic smoke exposure.
Avoiding Fireproof Unit Divisions
Dividing the parking area into smaller fireproof units—typically no larger than 1,000 m²—can hinder safety protocols and reduce parking capacity while also inflating costs due to additional smoke exhaust systems. Instead, our strategy is to follow established fire protection regulations for garages, allowing for smokeproof partitions of up to 2,000 m². This approach streamlines the design, enhances safety, and optimizes space for electric bus operations.
Ventilation and Smoke Exhaust Control Systems
To maintain air quality and mitigate fire risks, the garage’s ventilation system is designed to continuously expel waste heat and exhaust gases. Control mechanisms are implemented for seamless operation: exhaust fans are activated through manual or timed automatic controls and linked with air intake fans. In the event of a fire, the smoke exhaust fans can be manually activated or triggered automatically by the fire alarm system, ensuring a coordinated response that prioritizes safety.
Environmental Protection and Energy Efficiency
Given the electric bus depot’s urban setting, operational noise—though significantly lower than that of traditional fuel vehicles—remains a concern for residents. Consequently, we prioritized low-noise fan selection while maintaining adequate ventilation rates. To further minimize noise pollution, the design includes vibration isolation and sound insulation measures alongside sound-absorbing treatments for fan rooms. Additionally, our energy-saving strategies are highlighted by the implementation of timed automatic fan operation, promoting sustainability while ensuring compliance with community standards.
03 Project Overview and System Setup
Project Scope and Key Parameters
Located at the Shanghai International Medical Science and Technology Innovation Center, the Xietu Road Bus Parking Lot is an ambitious high-rise complex designed to meet the city’s growing demand for new energy transport infrastructure. Situated in Xuhui District, near Zhongshan Hospital and residential areas, this facility is subject to strict noise control and environmental standards. The building spans 26 floors above ground, with three floors underground, reaching a height of 120 meters. Covering a total planned land area of 25,109.8㎡, the project’s total construction area is an impressive 174,240㎡.
The parking garage itself occupies a substantial 85,340㎡, divided between the 58,100㎡ above ground and 27,240㎡ underground. This facility is specifically designed to accommodate both conventional cars and new energy buses. The underground levels provide parking for 794 cars, while the ground levels are reserved for 260 new energy buses featuring advanced charging infrastructure. The innovative parking strategy—dubbed “build four and park five”—maximizes space across four floors, with all levels equipped for electric vehicle charging.
Ventilation and Smoke Exhaust Systems: A Strategic Approach
First-Floor System Configuration
The first-floor parking area, designed for new energy buses, has a floor height of 5.65m and a net height of 5.45m. This level is divided into three key fire zones: 1F-3 and 1F-4 are designated for bus parking, while 1F-5 houses a maintenance workshop and management facilities. Each zone is equipped with mechanical ventilation and smoke exhaust systems tailored to the unique fire safety requirements of the area.
Second and Third-Floor System Configuration
On the second and third floors, new energy buses are housed in similarly structured spaces with a floor height of 5.65m and a net height of 5.25m. These levels are divided into multiple fire zones to optimize safety. Each zone features its own mechanical ventilation and smoke exhaust systems. The second floor also includes a management office and dispatch center, while the third floor is divided into two fire zones to ensure comprehensive safety measures.
Fourth-Floor and Roof Configuration
The fourth floor continues the theme with two fire zones, and like the lower levels, it is equipped with mechanical ventilation and smoke exhaust systems. The rooftop area serves as an open-air bus parking space, complete with charging stations. This arrangement allows for optimal air circulation, particularly for electric vehicle operations.
Ventilation and Smoke Exhaust Capacity and Fan Selection
Ventilation and Smoke Exhaust Volume Calculation
To ensure efficient airflow, the ventilation and smoke exhaust systems were designed with precision. For the first to fourth floors, ventilation is calculated based on a floor height of 3 meters and a frequency of six air changes per hour. The fan’s design air volume incorporates a leakage factor of 1.1, while fresh air intake is calculated to be 85% of the exhaust volume. Smoke exhaust volume is determined using parking garage fire protection standards, with each fireproof unit serving as a smoke-proof partition. The smoke exhaust fans are equipped with an additional 1.2 leakage factor for safety, and the air supply is set at 50% of the calculated smoke exhaust volume.
Fan Selection and System Integration
The selection of fans for both ventilation and smoke exhaust was critical. Each fireproof unit on the first to fourth floors utilizes a dual-purpose, low-noise cabinet centrifugal fan. The exhaust/smoke fan motors are mounted externally, while the fresh air intake fans have built-in motors. To further enhance safety, fans are powered by a dual system, drawing from both ordinary and fire protection power supplies. Fan models are selected based on the design requirements for fresh air intake, exhaust, air supply, and smoke exhaust, ensuring optimal performance across all fireproof units.
Control and Automation: Enhancing Efficiency and Safety
The ventilation system for the electric bus garage is designed for both day-to-day operation and emergency scenarios. Under normal conditions, exhaust and intake fans are controlled by either timed automatic start-stop mechanisms or manual controls. In the event of a fire, the smoke exhaust and air supply fans are activated through a combination of manual and automatic systems—either manually on-site or automatically through the fire alarm system. Each fire protection unit is equipped with independent ventilation and smoke exhaust systems, which are shared across the facility. Dual-speed fans are employed to allow for normal ventilation, switching to high-speed mode for smoke exhaust in the event of a fire.
04 Energy-Saving and Equipment Standards for New Energy Bus Parking Garages
Fresh Air Systems for Health and Hygiene
To ensure both safety and comfort, the ventilation system in the electric bus parking garage is designed to remove harmful waste heat and exhaust gases from charging operations. The ventilation system is built to handle at least six air changes per hour, ensuring that the working environment for both drivers and electrical equipment remains below 40℃. Fresh air intake systems are also set up to supply at least 80% of the exhaust volume, guaranteeing optimal indoor air quality. Natural air intake is utilized wherever possible, but in areas where it isn’t feasible, mechanical air intake systems are deployed to meet health and safety standards.
Noise Reduction and Vibration Isolation Measures
Given the location of the bus parking garage in the densely populated Xietu Road area, noise reduction is critical. The design limits noise to no more than 45 dB(A) during the day and 35 dB(A) at night. As the facility shares space with the International Medical Science and Technology Innovation Center, these limits are even stricter within certain areas—35 dB(A) during the day and 30 dB(A) at night. To meet these stringent standards, the project employs low-noise centrifugal fan boxes, vibration-damping bases, and spring hangers to minimize equipment noise and vibration. Silencers are also installed at fan inlets and outlets, and soundproofing measures are applied to ventilation rooms to ensure compliance.
Energy Efficiency: Ventilation System Optimization
In line with China’s energy-saving standards, the selected ventilators not only meet air volume and pressure requirements but also minimize power consumption. With the large ventilation demands of the electric bus garage—over 10,000m³/h—the fan power consumption (Ws) is kept below 0.27W/(m³/h), meeting stringent efficiency benchmarks. The actual design achieves power consumption values between 0.245 and 0.250W/(m³/h), ensuring energy-efficient operations. Automated control systems allow for the fans to operate in sync with fresh air intake, further reducing energy use and ensuring optimal performance.
In conclusion, the ventilation and smoke exhaust design for the Xietu Road New Energy Bus Parking Garage showcases a forward-thinking approach to urban infrastructure, balancing safety, environmental sustainability, and operational efficiency. By integrating advanced ventilation systems, noise reduction measures, and energy-saving technologies, the facility not only ensures the safety and comfort of its occupants but also meets the high standards required for electric bus operations in a dense urban environment. This project exemplifies how modern engineering can effectively address the demands of new energy transportation while adhering to stringent safety and environmental regulations.