People PowerProject Update

Using Hidden Existing Resources to Reduce Our Carbon Footprint

By May 10, 2018 No Comments

One of the goals of the AGU headquarters renovation project is to explore new ways to tap into site resources to reduce our carbon footprint. AGU and the project team are working out of the box by utilizing a municipal sewer heat exchange with help from hidden gems beneath Florida Avenue, right in Dupont Circle.

The sewer opened for wet well construction

The removal of the top to the sewer outside 2000 Florida Avenue in preparation for the sewer heat exchange. Photo courtesy of Skanska.

Exploration and HUBER Decision

What the project team then needed that was not already on site was a heat exchanger. In coordination with DC water – whose approval was required prior to implementation – the project team selected German manufacturer HUBER Technologies, and they were on their way! The project team explored more than 40 different individual engineering strategies, and the means for accomplishing one of the final 26 energy saving strategies in the building was just 30 feet below the surface of AGU’s headquarters. Interface Engineering saw an opportunity to connect the building to the existing storm sewer system beneath Florida Avenue to provide heating and cooling for staff and members when the project is complete.

Visit to HUBER Technologies

With only a handful of similar systems in North America, the project team took advantage of the unique opportunity to travel to Germany to see a fully functioning system firsthand and continue their research process. When visiting HUBER Technologies members of the project team got to see this system fully realized. They saw municipal sewer heat exchange systems powering buildings half the size of the AGU building, and buildings over double the size. The trip helped the team develop a way to safely tap into the sewer flow and take advantage of free cooling for a portion of the year. The project team came away from this confident in the technology’s reliability and efficiency.

Photo of a wet well in Germany

Members of the project team look within a wet well that pumps 800 gallons per minute of wastewater – heating and cooling an office building twice the size of AGU’s headquarters


One of the most unique aspects of this strategy is the coordination to implement the system, including delivery of the heat exchanger in the middle of Dupont Circle.

“The team is very excited and relieved to finally have the heat exchanger on site and see the design come together in real life,” representatives from Interface Engineering tell us. “This has been a long process of working through new technology and understanding what would work best in the application for AGU.” The heat exchanger was shipped from Germany on a boat and had to clear customs before it could then be placed on a truck and brought to the D.C. area! Planes, trains, and automobiles (and boats) were not going to stop this team from accomplishing their goal.

One way they adapted to what works best? Storing the heat exchanger in the garage of the AGU building. When Interface Engineering realized that the piping from the wet well and sewer outside are at roughly the same elevation of the garage, the project team took advantage of the garage location as to not have to use an unnecessary amount of piping between the two.

A story that starts with a trip overseas to Germany ends right here in Dupont Circle. A main piece of the system was set on Florida Avenue in late April. Now the project team is at an exciting juncture of the process as they work on the connection of the wet well on Florida Avenue. AGU and the project team look forward to sharing more lessons learned as the connection is completed and we hope you’ll continue to follow along on this exciting journey toward the goal of net zero.