Tour of a Deep Energy Retrofit

On Dec 20th, about 20 people participated in a tour of the Castle Square Deep Energy Retrofit project. Assembled by LISC (Local Initative Support Corporation)-Boston Program Officer, Elizabeth Glynn, the group came from a number of different housing agencies/organizations around eastern Massachusetts. Grey Lee, Sustainability Coordinator at Castle Square, co-facilitated the tour with Bruce Hampton (Elton+Hampton Architects), the lead architect on the project, and Tom O’Neil, from Pinck & Co, the CSTO (owner)’s rep in the construction project. Melissa Martinez from Pinck & Co also helped guide us and answer questions about the project. It was a great team of presenters and very cool to get access to “behind the scenes.” Below is Bruce and Tom explaining the energy savings – comparing the energy profile of “before” with “after” and describing all the different places (the segments on the bar chart) where energy savings came from. There was no silver bullet – the savings came from an integrated process coordinating technologies to provide incremental savings, adding up to the modeled 70% – amazing – savings.

We filed through one of the “hospitality suites” – one of the  units in the mid-rise (the buildings along Tremont Street) to see what it was like for the tenants. These suites are available for any resident to spend time in when any construction needs to happen in their unit, and they have nowhere else to spend the day. The tour participants were impressed by the quality of the general upgrade – the kitchens and bathrooms, the windows and various doors. The picture is looking onto the roof over the commercial space that CSTO rents out to small businesses along Tremont St. The workers are putting a hole through an insulation panel for the direct outside air intake vent – these enable a temperature-restricted flow of fresh air into the apartment while the ventilation system is gently pulling waste air out of each unit.

The group wanted to see what this big retrofit project was all about. Below is a picture of Tom O’Neil describing the three new natural gas furnaces in the rooftop mechanical room. Where everyone is standing was once a giant old oil-fired boiler. The white wall at the rear of the photo was open, through louvers, to the air. In winter, intake air was ambient temperature. Now, with the heat recovery system, building exhaust air from all the interior space passes through a heat exchanger (not seen here) on its way out, pre-heating the intake air for the system and enabling it to use less energy to bring everything up to the distribution temperature. Much more efficient. The red tank on the right is an expansion chamber for the solar-powered domestic hot water system, its storage tanks are larger out of frame to the right.

These three natural gas furnaces replaced a machine the size of a van in this room.

From the top, looking northwest, the towers of Boston’s Back Bay…Castle Square is in the heart of the city.

The tour group at the top of 484 Tremont St, CWC Construction workers getting the final exterior insulation panels fitted to the top of the mechanical house on the roof. In the foreground is a helmeted exhaust vent, part of the heat recovery system – the air coming out of the building, pulled by the fans of this unit, is heating intake air, thus it is cooler than directly vented interior waste air.

Here’s what we were looking at: The fabulous solar hot water arrays.

This is a shot looking up at the underside of the solar hot water system. I should have rotated it but either way, you can see the plumbing. 20% of the hot water will be heated through these panels. Maybe we can work on another grant to get more of these things upstairs!





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