Stevens Institute of Technology
Nine seniors dedicated their capstone project to developing a sustainable plan for harvesting wasted thermal energy from the subway system to provide hot water to local buildings.
According to the New York City government, the single largest source of the city’s greenhouse gas emissions is not car traffic or the subway system: it’s city buildings, which generate approximately two-thirds of the city’s total carbon emissions.
One major culprit of these emissions is boiler systems, which burn fuel oil to supply heat and hot water to the buildings’ occupants. When burned, these fuel oils create carbon dioxide, which is then released into the atmosphere. In excess, carbon dioxide contributes to global warming and climate change.
To address the problem, the city passed Local Law 97, which imposes increasing fines every five years on most buildings larger than 25,000 square feet that generate carbon emissions above a certain threshold. Going into effect in 2024, these annual limits aim to reduce greenhouse gas emissions from city buildings by 80% by 2050.
At the same time, anyone who has spent even just minutes in a New York City subway station knows that these predominantly un-air-conditioned stations get hot.
The combination of thousands of travelers’ body heat, friction generated by the subway trains’ movement, and the electricity needed to run the trains’ motors, braking systems, onboard air conditioning units and other electrical components can routinely push the temperature in some stations to above 90 degrees Fahrenheit — even in wintertime.
“All of that electricity makes a lot of heat as a byproduct,” explained Stevens Institute of Technology fifth-year mechanical engineering major Drew Maggio ’23.
Solutions to both problems came together through the 2022-2023 senior capstone project, “NYC Subway Heat Recovery.”. . .
Continue reading at Stevens Institute of Technology.