Design-build retro-commissioning (DBRCx) is a new approach Grumman|Butkus Associates (GBA) has developed to assist a large for-profit health care organization in implementing a nationwide retro-commissioning (RCx) program across multiple hospitals. During the past 10 years, RCx has become a standard method for achieving energy savings for institutional, commercial, and industrial facilities. Savings typically target 3%-6% of the utility bill and result in a one- to two-year simple payback of the direct measure costs (material and labor to implement the measure), not including the engineering effort to identify savings opportunities or provide measurement and verification (M&V) services. A typical project starts with an engineering team that identifies savings opportunities. The owner selects the measures, a contractor completes the implementation, and the engineering team verifies the savings; sometimes, third-party verification is also provided. Many local utility programs offer incentives ranging from covering the engineering analysis costs to cash incentives based on verified savings from the projects implemented.
In 2017, GBA was hired to implement a combined RCx and monitoring-based commissioning (MBCx) program across 27 acute care facilities. While the organization owns all the facilities, the hospitals are independently run by local C-suite and facilities teams. The portfolio varies in size (square footage), number of beds, and type and age of equipment. Some facilities have central heating and cooling plants with large, built-up, custom air-handling units with a central building automation system (BAS). Others rely on smaller, locally controlled DX systems.
Since the client does not have a corporate presence at each facility, the request for proposal (RFP) required that the selected team provide full turnkey services for each project. This included not only providing traditional RCx services but also developing engineering drawings and scopes of work, bidding the implementation of the measures, hiring the contractors, overseeing construction, providing project/construction management services, and verifying the energy savings through utility bill and trend analysis.
FIGURE 1: A synopsis of the retro-commissioning (RCx)/monitoring-based commissioning (MBCx) program process.
Images courtesy of Grumman|Butkus Associates
The client also wanted to launch a standardized MBCx platform at each site for two years to provide online trend data and to continuously validate the energy savings for the implemented measures. MBCx also helps verify the measures’ persistence over time. The client’s goal was for each site to save 20% of HVAC energy consumption with a full-program simple payback of four years. The program was funded by the client for four years with the corporation identifying the sites where GBA would launch the RCx/MBCx program on a rolling basis.
GBA, a full-service mechanical, electrical, plumbing, and fire protection design and energy consulting firm, has been providing licensed professional engineering services nationwide for more than 40 years. GBA has become a reputable source for HVAC infrastructure design, RCx, MBCx, and new construction commissioning for health care, higher education, laboratory, hospitality, and commercial buildings. As a consultant, GBA was not initially set up to hire contractors. To provide the turnkey services requested by its health care client, GBA created a new company, GBA Services, obtaining the necessary licenses and insurance policies dictated by the client and the authority having jurisdictions (AHJs) to hire the contractors to implement the work.
The turnkey/design-build project setup led to many challenges and successes for GBA and for the client, some of which are summarized below.
FIGURE 2. Verified cost savings of the implemented measures.
Speed: If corporate red tape or utility protocols are not constraints, DBRCx can have significant schedule advantages over the traditional RCx planning, investigation, implementation, and verification phases.
Single Point of Contact/Less Owner Staffing: Streamlined communication and responsibility to the DBRCx team optimizes owner staffing and the internal workload.
Transparency: Unlike a traditional performance contract, where the owner is “blind” to the process, GBA reviewed all measures selected for implementation with the site operations staff and the client, procured multiple bids for implementation and shared results with the client, submitted actual trend data and went through a detailed calculation spreadsheet and M&V review process, and did a final utility bill verification of savings. The DBRCx provider can be held more accountable than a typical performance contractor, giving the owner confidence the dollars spent and savings achieved are real and justified.
Technology: The DBRCx provider can often bring enhanced technology and expertise to the owner.
FIGURE 3: GBA's in-house fault detection platform (Trend Sumo®) workflow.
Financial savings: If the right DBRCx provider is selected, the owner can see improved financial returns and payback for dollars spent since the same provider is doing all the steps from planning, investigating, implementing, and verifying. This assumes the selected DBRCx provider can provide or oversee all these tasks.
Cash flow for the DBRX team. Owners wishing to leverage the DBRCx process may be slow payers. This means delayed payments to the DBRCx provider and its subcontractors, which can lead to work schedule issues or difficult negotiations over payment terms.
Less information and details for the owner. By its nature, the DBRCx process puts all the responsibility for producing results on the DBRCx provider. This means the owner is significantly less involved in the details and financials for the projects.
Less involvement from the owner means more work for the DBRCx team with the project site teams.
Conflict of Interest: If the DBRCx provider is solely tasked with calculating the energy savings, providing financial estimates, and verifying the savings, this scenario can be a potential conflict of interest.
Capabilities of the DBRCx provider:
In addition to the successes and challenges listed above, GBA has some lessons learned for future projects.
Selection of sites: If a corporation-wide program is being implemented, GBA recommends working with the DBRCx provider in the selection of sites and the order for implementation. Going by physical size or using a marker, such as an ENERGY STAR score, does not paint the whole picture of a site’s operations, especially in the health care field. A number of factors, such as staff availability, type and age of the equipment, relationship with the local controls contractor, and vintage of the BAS, all contribute to the success of a project. GBA recommends a preliminary review of the utility data along with a one-day site visit to each facility, allowing the DBRCX provider to interview site staff and review existing operations and condition of the BAS. Each facility in a portfolio can then then be ranked according to RCx/MBCx potential. Some sites may end up requiring so much infrastructure or capital work that the owner may opt to save them for later phases or remove them from the DBRCx program.
BAS conditions: The BAS does not need to be the latest and greatest for a project to be successful; however, if the system is so out-of-date that new sequences of operations cannot be programmed, it is a nonstarter. Additionally, if traditional M&V through trend analysis is planned, trending in the BAS is needed. Data loggers can be utilized, but a large-scale data logger approach is slower and more cumbersome than utilizing the BAS. An MBCx platform is an alternative option for trend analysis, as discussed below.
MBCx platform: Depending on the MBCx platform type, the BAS system or the controls network itself may need to be upgraded. This should be evaluated for each site at the start of the project.
FIGURE 4: Pre and post measure implementation trend data.
Operations and Maintenance (O&M) Issues: For each site in a multisite program, GBA recommends that corporate allocate $20,000-$50,000 upfront for O&M issues found during the initial investigation phase. These issues typically impact the normal operation of a system, such as problems with dampers or actuators, but fixing them may result in minimal, or hard-to-quantify, energy savings. Nevertheless, dollars are required to repair these issues so implementation of the identified measures can succeed. If such items have to be included in the measure costs, the simple payback is negatively impacted.
Infrastructure/Capital Planning: During the course of the investigation phase, many opportunities may be identified that, when bid to contractors, might not meet the program’s simple payback requirements. The item then becomes a capital measure. GBA recommends the owner coordinate capital planning with the site teams and the DBRCx provider so that during future projects the additional measures identified can be included when appropriate or budgeted for future work. GBA has created a tool called an Infrastructure Report Card that grades a site’s MEP equipment based on general conditions and energy efficiency, which can provide a capital roadmap for replacement.
FIGURE 5: GBA's infrastructure report card summary table.
Overall, DBRCx can be an effective tool for large-scale energy savings initiatives, leveraging the expertise of the engineering provider and taking burden off the owner’s team. In the DBRCx initiative profiled in this article, 14 facilities have now completed the two-year project. The client has invested more than $9 million, resulting in a verified 19% HVAC energy cost savings and a 3.8-year simple payback, programwide. The results have successfully met the client’s program requirements.