‘Green steam’ heats a historic commercial building in Downtown Crossing
Vicinity’s upgrade to the original heating infrastructure is saving this historic building thousands in energy costs per year.
For over 40 years, the Boston district energy system has supplied steam to this iconic former bank building in the city’s bustling Downtown Crossing district. Under a renewed long-term agreement, Vicinity Energy has continued to supply ‘green steam’ to the building, which is used for heating and hot water. As part of this new 2015 agreement, Vicinity upgraded the building’s original heating infrastructure, while the building’s owners, the Clarendon Group, developed a steam condensate system that recycles waste heat to preheat domestic hot water – two creative solutions that are helping conserve water and reduce energy consumption and costs.
Built in 1925 and located along the historic Freedom Trail, 10-24 School Street has welcomed a wide variety of tenants in its 90+ year history. Originally constructed as an office and retail space for the former Boston Five Cent Savings Bank, the building space is now occupied by Walgreens Pharmacy. In a collaboration between the Boston Redevelopment Authority and the Clarendon Group, Walgreens Pharmacy has leased the space for its upscale flagship store since 2012, which includes a pharmacy, prepared food, a nail salon, juice bar and a sushi counter.
In 2015, Vicinity and Clarendon Group partnered on a renewed long term supply agreement for ‘green steam’ service to the building. Using Vicinity’s ‘green steam’ to provide heat and hot water avoids the upfront capital costs and space required for an onsite boiler plant, improves reliability and contributes to the Clarendon Group’s sustainability goals. This highly efficient steam is produced using advanced Combined Heat and Power (CHP) technology at Vicinity’s Kendall Cogeneration Station and distributed to the building through a series of underground pipes.
As part of this agreement, Vicinity also supported the upgrade of the building’s original heating infrastructure to a new, efficient system – removing unnecessary piping from the original steam system design and installing all new piping, valves, traps and insulation. Following the success of these upgrades, the Clarendon Group advanced another efficiency project in 2016 to reuse the waste heat in the steam condensate. Although this high temperature water is often cooled with city water and discarded as waste, the Clarendon Group sought creative ways to recycle the condensate. By installing a heat exchanger that uses condensate to preheat domestic hot water before it goes into an electric hot water heater, the building is saving on energy while also reducing its city water costs.
Through a combination of improvements, including reusing the condensate and new steam infrastructure, the Clarendon Group is converting former waste streams into usable energy, while also significantly reducing its costs. By reusing the condensate waste heat, the building is not only saving on sewer charges and city water costs for tempering the condensate, but also conserving water – one of our most precious resources. The Clarendon Group is continuing to improve its energy utilization with other planned efficiency projects in development to further reduce energy consumption. The upgrades have delivered immediate cost savings – resulting in an annual reduction of steam consumption by over 30 percent.