In Sydney, Australia, the particulate matter concentration on train platforms is 1.1 times higher than inside the train. The particulate matter level was even higher for below-ground stations.
Are you doing enough to manage the air quality on your rail platforms?
Keep reading as we explore the requirements for a metro tunnel ventilation system, and the consequences of poor ventilation in train stations.
Which factors affect air quality in stations?
In railway stations, vast, open spaces can be subject to significant draughts. The large entrances allow strong gusts of wind to pass, making the area uncomfortable for pedestrians and travelers.
Additionally, many gases and pollutants are produced by trains and station operations. The platform area and entrances can create a chimney effect with these gases, generating a pressure change between the platforms and the station concourse.
These gases can be harmful to inhale and present a combustion risk. To manage these risks, you can implement air curtains and ventilation. Air curtains create a ventilation barrier, sealing the train station entrances so that breezes do not enter and the chimney effect cannot occur.
What are the regulations and requirements for metro tunnel ventilation systems?
The NSW government has set out guidelines for ventilation, cooling, and heating in metro tunnels. These regulations highlight the importance of smoke management and smoke exhaust, for location-specific fire and life safety strategies. It notes the importance of keeping public spaces within 5 degrees Celsius of ambient temperatures. Air conditioning can be effective in complying with these regulations, in addition to natural ventilation and awnings. A combination of air conditioning and ventilation system supply and exhaust points is recommended.
For metro tunnels, there should be a tunnel smoke extract system to control the propagation of smoke. The amount of extraction equipment required directly correlates with the tenable conditions required for a fire emergency, ensuring ample time for an emergency evacuation of the tunnel. The exhaust and discharge points should be located over 12 metres from any surrounding air intakes (including entrances, openings from platforms, and ventilation air intakes).
It’s important to work with ventilation experts during the construction, design, and planning processes for a metro station. Experts will have extensive knowledge of metro tunnel ventilation standards, helping you to ensure compliance with the finished result.
What’s an example of a successful metro tunnel ventilation system?
Sydney Metro North West consists of 36 km of track and 8 railway stations between Chatwood and Rouse Hill – the longest rail tunnels in Australia. To meet the ventilation requirements and regulations for metro stations, the tunnels were equipped with axial fans for both the tunnel ventilation and tunnel exhaust systems.
The fans were designed to withstand fire conditions, able to operate for up to 2 hours under temperatures up to 300 degrees Celsius. The execution of this system ensures fire safety, reliability, and compliance for Sydney Metro North West.
Dangers of poor ventilation in train stations
Below is a list of the consequences of poor ventilation in train stations, highlighting the need for a robust ventilation strategy.
Thermal regulation
In subways, the thermal environment can have a strong effect on human health, indoor air quality, airflow, and sound transmission. Vapor condensation, humidity radiation, and indoor air pollution contribute to increased temperature and humidity in a train station.
This risks worker comfort and health, increasing the likelihood of heat stress with strenuous manual labour. Almost every bodily system can become overworked with excessive heat, leading to issues with the cardiovascular, digestive, endocrine, immune, skin, muscular, nervous, reproductive, respiratory, skeletal, urinary, and auditory systems.
To regulate the temperature, ventilation circulates the air, helping to dissipate heat, pollutants, and humidity produced by station operations. The temperature will be even throughout the premises, without stagnant air pockets or stratification (the process of hot air rising and cold air sinking).
Humidity
Humidity can affect passengers’ and workers’ environmental perceptions, placing their health at risk. If the relative humidity level (RH) reaches over 70%, this can lead to severe discomfort. Humidity makes it harder for the body to perform its natural evaporative cooling processes, removing heat via the evaporation of sweat. Since the air is already full of water vapour, the water on the skin won’t evaporate as quickly. This can lead to dangerous cases of overheating for passengers and workers in the station.
VOCs
Volatile organic compounds (VOCs) can be thick in the air at train stations when passengers are exposed to high levels of VOCs, leading to irritation of the eyes, nose, and throat. These compounds can also cause headaches, loss of coordination, nausea, and damage to the liver, kidneys, and central nervous system. Without proper ventilation systems, subways can account for 10-20% of VOC exposure for passengers and even more for workers.
Other air components
Subway operations cause the emission of other air components such as CO, CO2, and NO2. These gases can rapidly accumulate in a train station environment as there are many confined spaces with large populations and various sources of these gases. If exposure is not managed, occupants in the facility are at risk of suffocation and respiratory conditions.
Top ventilation solutions for train stations
Now you understand why ventilation is so crucial in train stations, let’s discuss the top solutions to invest in for your rail facility.
- Profile base hooded roof fan – This ventilation system is easily installed on the facility’s roof, meaning it can be installed without interrupting foot traffic. The fan removes stuffy hot air that rises to the ceiling, moving it out of the structure. It also removes dust, fumes, and contaminants to maintain cool temperatures and clean air. This ventilation solution helps keep your staff and passengers safe and comfortable.
- Air curtains – Air curtains are easily installed above entrances or exits in your facility, creating an invisible air barrier to prevent draughts and the chimney effect in train stations. They can keep your facility cool in summer, preventing hot air from outside and replacing the cool air from your cooling units.
Pairing these solutions creates the perfect ventilation strategy to manage air quality in train stations.
Choose Fanquip for train station ventilation
Ventilation in train stations prevents workers and passengers from being exposed to high heat and humidity levels, along with the harmful fumes produced by trains. Managing these factors with ventilation helps promote safety and comfort in your facility.
Do you need help planning your train station ventilation strategy? Contact our expert team of ventilation advisors to begin the installation process.
