Metrolinx is working to prevent the transmission of COVID-19 aboard trains and buses.
In a recent report released by Metrolinx, company Media Relations & Issues Specialist, Nitish Bissonauth, cited reports from engineering and public health experts that suggested: “Increasing the amount of clean or outdoor air delivered to any area per hour reduces the risk of transmission of viruses through the air and therefore lowers the risk of contracting the disease.”
As a result, Metrolinx is implementing an air circulation system in order to help prevent the spread of the virus.
“Each bi-level train coach has two units—a heating ventilation and an air conditioning unit, also referred to as an HVAC unit,” Bissonauth said.
The HVAC has two fresh air intake ducts and grilles, one return air grille and the main air supply duct, and fresh air enters the HVAC through the grilles that are located on each side of the coach’s exterior.
The air then passes through the HVAC before being filtered and pumped inside the coach.
Through this process, the air being circulated through the coach is 20 per cent fresh, while the remaining 80 per cent is recycled.
“It’s impossible to have 100% fresh air as it would make for a very uncomfortable train ride,” Bissonauth said.
The recycled air is needed to maintain a comfortable temperature for passengers.
The air filters are designed to ensure the air is safe to breathe.
“The fresh air from the outside goes through a MERV 13 filter, and then that air is recirculated inside the coach through a MERV 8 filter,” Bissonauth said.
The effectiveness of the ventilation system depends on how well it moves air, which can be measured by how many times the coach is supplied with air in an hour.
“The air inside a GO train coach is replaced 10 times per hour with fresh air and 50 times per hour when mixing in recirculated air, a frequency that meets or exceeds public health guidelines,” Bissonauth said.
Additionally, GO Transit maintenance crews perform daily checks on the HVAC system in order to ensure they are functioning properly, and providing passengers with safe, clean air.
Further, according to Bissonauth: ”The transit agency is continuing to monitor its air purification system closely, conducting feasibility studies to find out if there are any additional solutions that could add another level of air purification.”