General Overview

1. What is the Building Re-tuning Simulator (BRS)?
   
   The BRS is a free, easy to use, online tool that helps identify low-cost and no-cost re-tuning measures. Re-tuning relies on building automation system (BAS) data to identify and implement controls measures that improve the building's energy efficiency, reduce operating costs, and improve occupant comfort.
2. What is Building Re-tuning?
   
   Re-tuning is a data-driven process of improving control of existing building energy systems, centered on the BAS, through the application of four key principles:

   • If you don't need it, turn it off
   • If you don't need it at full power, turn it down
   • Mitigate simultaneous heating and cooling
   • Reduce infiltration and unnecessary outdoor air supply

   It is systematic process aimed at minimizing building energy consumption by identifying and correcting operational problems that plague buildings. The investigative process of re-tuning can also uncover and diagnose HVAC equipment deficiencies that require corrective actions.
3. What are the benefits from using the BRS?
   
   The primary benefit is that users are provided with a way to estimate via simulation the energy and cost impacts of various re-tuning control measures before their implementation. This allows users to test control settings and prioritize solutions for implementation. The BRS simulation also includes a limited number of operations and maintenance (O&M) and capital project measures.
4. Where can I learn more about Building Re-tuning?
   
   There are several building re-tuning resources available. See the Training and Resources pages for more information.
5. Does the BRS re-tune buildings?
   
   No. The BRS develops estimates of energy consumption, cost, and savings for the selected re-tuning measures based on simulations. Selection and actual in-field implementation of the re-tuning measures are done separately by building O&M personnel.
6. How long will it take to complete the BRS?
   
   The BRS is designed to be a simplified building energy model with the goal of reducing the required time and effort for the user to collect data and interface with the tool, relative to other detailed energy modeling software tools such as EnergyPlus. The BRS requires data collection and analysis processes that can be approached with varying degrees of detail. Therefore, the time needed to go through the entire BRS simulation process can vary significantly based on the building type, level of detail incorporated, and amount of staff time allotted to the process.
7. What types of support does the Department of Energy provide to users of the BRS?
   
   The BRS is designed to be used independently by personnel that are engaged in the re-tuning process. FEMP is available to answer user questions and provide limited technical assistance. Please contact FEMP using the Assistance page for more information.

Site Level Planning

1. What should I do before using the BRS?
   
   There are three steps that should be taken before using the BRS.

   • Step 1. Screen the building to determine if it is a good candidate for re-tuning. This can be done by completing the Re-tuning Candidate Checklist.
   • Step 2. Identify staff that will be able to provide building-specific knowledge support for HVAC systems, controls, and building operating requirements. Staff supporting the BRS and re-tuning processes may include the building manager, energy manager, operations and maintenance contractor, and controls technicians/contractors.
   • Step 3. Review the BRS databook before entering into the BRS tool to determine availability of the building, equipment, and operations data needed to complete the BRS modeling.
2. What are the attributes of a good candidate building for applying the BRS?
   
   Buildings being considered as candidates for BRS application should be reviewed for both the overall re-tuning potential of the candidate building and the capabilities and availability of the staff that will use the BRS. The re-tuning potential of any building can be screened using the Re-tuning Candidate Checklist tool.
3. What building staff are needed to support the use of the BRS along with re-tuning and sustainment of improvements?
   
   Staff supporting the BRS and re-tuning processes may include the building manager, energy manager, operations and maintenance contractor, and controls technicians/contractors.
4. Are there any equipment or building systems required for using the BRS?
   
   Yes, the BRS was developed for application in buildings with a building automation system (with trending capability at a minimum). In addition, the building controls and controlled components must be operating properly in order for the simulation to accurately reflect the actual operation and the potential for savings in the building. There is one notable exception. The BRS does allow the user to simulate leaking coils, which may be the result of faulty hot water or chilled water valves. The user can then evaluate the impact of re-tuning measures in the presence of such a leak or evaluate the correction of the leak as part of an O&M measure.
   
   For buildings without building automation systems, a very limited set of re-tuning measures may still be possible. See the Training page for more information.
5. What is the difference between a building model and a simulation?
   
   A building model is a simplified representation of an actual building. It includes key characteristics of a facility and is typically used for evaluating the impact of changes in control, changes to equipment, or changes to envelope properties as opposed to predicting energy use in a new building.
   
   A simulation is the process of using the building model to study the behavior and performance of the facility. This is done by manipulating variables to evaluate system performances and calculate energy and cost savings.
6. Does the BRS provide information about Healthy Building aspects or impacts?
   
   No, the BRS does not directly address Healthy Building aspects or impacts. Healthy Buildings measures typically focus on indoor environmental quality (IEQ) in combination with energy efficiency. Re-tuning measures affecting space temperature and airflow directly affect IEQ, but IEQ is not addressed specifically in the BRS.

Website Access

1. Is there a cost to use the BRS?
   
   No. The BRS is available free of charge.
2. Does the BRS require any special connections, software apps, or downloads?
   
   No. The BRS is a free, web-based tool that operates using common browsers such as Chrome, Firefox, Microsoft Edge, and Safari. The user only needs a stable internet connection to use the tool.
3. Does the BRS require users to register?
   
   Yes, registration is required to use the BRS. The user must have a valid email account.
4. Is the BRS website secure?
   
   Yes, the BRS website is part of a federal computer system used to accomplish federal functions. Pacific Northwest National Laboratory (PNNL) both actively monitors the network traffic and the software on the web server.