Revolutionizing Efficiency: SCDOT Headquarters' Energy Transformation

The Challenge

It was time to drive change at the South Carolina Dept. of Transportation (SCDOT) headquarters building. While the approximately 900 employees in the six-floor building diligently focused on maintaining a safe and reliable state transportation network, their own building struggled to provide a comfortable place to work. 

Constructed in 1977, the 222,000 square-foot building, which houses executive offices, a data center, emergency response employees and multiple administrative offices, had been “chopped up” to accommodate changing space needs over the years. Unfortunately, the infrastructure systems were not updated when the building’s space was reconfigured.

As a result, hot and cold spots plagued employees throughout the building. During summer months, for example, occupants faced chilly, sweater-clad mornings with the thermostat set to 65 degrees F. This low temperature was established in the morning to try to cap the building’s late-afternoon temperature at a sweat-inducing 80 degrees. 

Beyond the temperature issues, humidity in some building areas skyrocketed to more than 60 percent on hot days. The lighting also had not been modified when building changes were made so controls didn’t match current office configurations. New staff shutting the lights off could suddenly find that their light switch managed multiple office locations.

Additionally, the building’s original heating and cooling systems, including outdated pneumatic controls, were proving to be increasingly unreliable and inefficient. Further complicating the scenario, the facility was purchasing steam and chilled water from a 42-year-old, remote, degrading central steam and chilled water system located nearly a half mile away through underground piping and under multiple lanes of traffic. 

SCDOT also was financially responsible for repairing any leaks along the nearly five-block route to their facility. Staff could see evidence of steam leaks along the route to the building, an indication of the system's inefficiency and a literal view of agency costs vanishing into thin air. 

Facilities management staff were spending an estimated 30 to 40 percent of their time “putting out fires.” Managing building challenges was significantly impacting their day-to-day productivity. Building infrastructure upgrades were badly needed, but the agency needed a way to fund them. “We wanted to come off the central plant, address issues on our own, and decrease our energy cost,” said Roger Sears, PE, SCDOT Headquarters.

The Solution

After soliciting due diligence proposals, SCDOT leaders selected Trane to address building improvements based on Trane’s proposal and previous experience addressing the building’s unique needs.

Leaders also liked that Trane proposed a performance contracting solution that would allow the department to pay for the improvements with forthcoming energy savings, eliminating the need for an upfront capital outlay. The solution included equipment and controls upgrades, lighting improvements, and water conservation measures. 

Before beginning work, the project team undertook an investment grade audit that identified specific improvements needed. They also completed energy modeling which identified the energy savings each potential solution could provide and based on that, selected their energy conservation measures.

Alleviating expensive contract services 
The project team focused first on constructing a new water-cooled chiller plant on the building’s ground-level parking deck, eliminating the need to source chilled water from the central system nearly half a mile away. The team implemented the industry’s highest efficiency chiller, a 600-ton variable speed Trane® CenTraVac® centrifugal chiller in a variable primary flow configuration for reliable, robust performance.

The department also eliminated the need to procure steam from the remote central system by building a new high efficiency, condensing boiler plant and boiler room in the penthouse of the building. The project team added two identical, natural-gas-fueled boilers, providing redundancy in case one boiler should ever fail. “We now have on-demand gas boilers,” said Sears. “They only heat when needed and are much more energy efficient.”

Upgrading technologies, implementing conservation measures 
To help improve the comfort inside the building and eliminate hot and cold spots, the project team updated the air handling system, which also enhanced redundancy and efficiency, driving additional energy savings.

SCDOT implemented plumbing fixtures with low-flow devices throughout the building to conserve water. They also completed a comprehensive interior and exterior lighting upgrade, replacing existing T8 lighting with new energy saving LED fixtures. 

Optimizing building operations, energy management and lighting
SCDOT wanted to be able to manage issues on their own, and a key factor that allowed them to do so was the conversion of the building’s pneumatic controls to a Trane Tracer Ensemble web-enabled enterprise-wide, building management system (BMS). This BMS enables the SCDOT management team to remotely monitor vital building performance metrics, manage energy use, access long-term data collection, generate reports, and identify improvement opportunities for more informed decision making and increased productivity.

The platform includes Tracer Ensemble Cloud which provides software as a service (SaaS), hosted and managed by Trane, simplifying building management. It connects to SCDOT systems, but does not require a server or IT support, reducing both up-front costs and ongoing support.

The team also added Trane Intelligent Services® which provides real-time energy use data, system performance analysis, and ongoing consultative services to help increase energy efficiency, operating income and sustainability into the future. With visibility to what is happening in their building, facility managers are now able to fine tune operations to further help to drive down energy use and costs.

Lastly, to address the lighting configuration issues, the building’s lighting was also upgraded so that it could be controlled by occupants, and occupancy sensors and dimming capabilities also were added in appropriate areas. 

Providing effective project management for seamless installation
The Trane installation team completed major electrical upgrades to support the chiller plant, addressed code requirements, coordinated asbestos abatement during the air handling system retrofits, and performed seismic constraint upgrades for new gas piping. 

With the building being 100 percent occupied while upgrades were completed, and designated as the state’s emergency broadcasting center, project implementation required significant coordination between SCDOT and Trane project management. The project team scheduled much of the construction on weekends, so as not to disrupt normal business operations. The project team completed the complex project on time and on budget while working in the fully occupied building.

The Results

The improvements reduced the building’s energy use by 41 percent from $2.5 per square foot to $1.48 per square foot while helping to improve building comfort, indoor air quality and lighting.  Staff report that grievances about building comfort dropped from multiple daily complaint phone calls to nearly zero complaint calls once the upgrades were completed. 

The building upgrades significantly increased staff productivity, especially for the facilities management staff, as the building is now easier to manage and control. The agency disabled its connections to expensive centralized utilities, alleviating its potential liability for an aging buried piping infrastructure. The building is realizing a 19 percent reduction in kWh and an 85 percent reduction in therms. The project is expected to save the agency more than $258,500 with an operational cost savings guarantee of more than $75,425 annually.  

“The comfort levels and tenant satisfaction in the SCDOT building are tremendously higher and these improvements would not have been possible without the use of the Guaranteed Energy Savings concept,” said Sears. “This project also enabled SCDOT to win the Association of South Carolina Energy Managers ASCEM Energy Project of the Year Award for 2020.”