Learn the Building
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This workstream provides vital information on current challenges, near and longer-term carbon reduction opportunities and the accuracy of the energy model. It also creates early wins that build momentum and trust. Getting the most out of this work requires trust-based collaboration across facilities managers, operations staff, the energy modeler, external contractors and design engineers. Engaging with tenants to get insight into what drives their loads can also be valuable to the process. Data and insights on the existing conditions of the building typically arise from four sources:
- Design documents
- Data from metered systems
- Direct observation and testing
- Building operations team feedback
Each source is important, but it is the integration across these four categories of data that leads to deep operational insights and identification of major areas of opportunity.
Getting the most out of this work requires trust-based collaboration across facilities managers, operations staff, the energy modeler, external contractors and design engineers. Engaging with tenants to get insight into what drives their loads can also be valuable to the process.
Gather Information: In this phase, project teams should work with the building management and operations teams to collect the information shown below here in the sample Information Gathering Checklist:
Why is this Information Needed?
- Floor Plans
- Elevation Drawings
- Vertical Floor Dimensions
- Tenant Fit-out Drawings
- Façade Cut/Detail Sheets
- Window Cut/Detail Sheets
Architectural drawings will be used to build the energy model geometry and assign performance characteristics to exterior wall assemblies.
Mechanical, Electrical and Plumbing Drawings
- Mechanical Schedules
- Mechanical Riser Diagrams
- M-Drawings (Schedules) of Retrofit/Upgraded Equipment or a Description of Changes
- Electrical Schedules
- Electrical Riser Diagrams
- Lighting Schedules and Detail Sheets
- Plumbing Schedules
- Plumbing Riser Diagrams
MEP drawings will be used to build the energy-consuming systems in the energy model. These documents will also inform opportunities for equipment replacements based on end of useful life and can be referenced when evaluating equipment locations and available space.
- Minimum 12 months of data for all incoming utilities including electricity, natural gas, district steam, fuel oil.
- Data from tenant electrical sub-meters (if available)
- Data from central plant BTU meters (if available)
Building utility bills showing annual energy consumption and tariffs are required to create an initial energy model. Utility bills allow the energy modeler to calibrate the total energy consumption and the breakdown by fuel type, which is important to track as different fuel sources have different greenhouse gas emissions and associated energy costs.
BMS Information - The BMS may be a source for a wide variety of operational data such as:
- Fan run hours
- Damper and valve positions
- Air and water flow rates
- Air handling unit supply air set points
- Space temperature set points
- Air, water and space temperatures
- Chiller/cooling tower/boiler entering and leaving water temperatures
- Pump flows during peak and off-peak times
- Fan and pump electrical consumption and demand data from VFDs
The main parameters to collect are:
- Meter data
- Equipment hours of operation
- Temperature setpoints
- Data trends
- Fault detection
- System mode (manual versus override)
Historical data from the BMS can help align modeled energy use breakdowns with actual operation. Collating and reviewing this data can provide insights into building operations. Sometimes building operation differs from the document design, standards, and even the facilities team’s own understanding as system modifications are made incrementally over the years. Live data can be used to verify system schedules, turndown, and setpoints and drive even more accurate modeling of building operations. Building management systems provide insight into how the building is performing in real-time.
Information gathered from building operators can provide deep operation insights, serve to develop trust, and identify areas of opportunity for improvement.
Existing Capital Plans
It is also important to gather data on the “business as usual” (BAU) plan for future capital and operational expenditures. Doing so allows the team to compare ECMs against already planned expenditures and to begin to understand the sequence and timing of ECMs within the context of already-planned building upgrades.
Lease Turnover Schedules
Having insight into lease turnover schedules can help define opportunities for engaging tenants in the low carbon retrofit process, and identifying proper phasing of decarbonization solutions in tenant spaces.
Survey the Building:Understanding a building’s existing conditions requires time on-site. Design drawings, operator interviews, and utility data all provide valuable insight, but do not capture the nuances of how the building runs day-in and day-out. Project teams should plan to conduct an initial site walkthrough to confirm high level information about the building equipment, systems and operations strategies shortly after project kickoff. As the study unfolds, additional site visits to verify information, gain additional clarity on certain conditions, or evaluate the feasibility of implementing ECMs will be necessary. The more time the project team spends in the building, the easier it will be to reflect the building’s existing conditions in the building energy model and to develop ECMs that are feasible. When walking the building, the team should evaluate the following:
- Space temperatures : does the space temperature feel too low or too high?
- Infiltration conditions: are there noticeable drafts within the space?
- Pipe trim and valving: is there proper instrumentation within the system?
- Unoccupied space conditions: is equipment running when it should be off?
- Central plant operations: is equipment running more often than it needs to be?
- Piping/duct conditions: are there noticeable leaks or inefficiencies within the distribution?
- Multiple controls for different equipment within a single space or physically grouped thermostats: is it possible that the controls are causing conflicting operation?
Deploy Additional Metering (if required): Collecting documentation and surveying the building will highlight gaps in data or information needed to build a calibrated energy model. To fill these gaps, the project team may elect to deploy additional metering to capture the missing information. Metering ultimately reduces speculation and provides real-time insight into the building’s operations. Project teams should execute the following steps when developing a metering strategy:
- Identify and create an inventory of existing meters, submeters and instrumentation.
- Verify the accuracy of existing meters and ensure they are properly connected and integrated in the building management system (BMS)
- Gain direct access to view the BMS data. Ideally, the team will have viewing access to real-time building operations during the entire duration of the project.
- Identify areas where additional meters will be required.
- Develop a deployment program for additional metering needs including preferred vendors, meter types, meter quantities, locations for placement, and an installation schedule.
Observe and Test Systems:Building system assessments and functional tests are great ways to capture operating parameters, evaluate performance, and identify issues that can be resolved with retro-commissioning. Project teams should conduct some or all the following building tests to further inform the study:
Building envelope performance and infiltration
Understand the conduction losses/gains through the envelope. This will inform potential envelope opportunities and the baseline energy model.
Refer to ASTM E1186 – 17 for standard practices for air leakage site detection in building envelopes and air barrier systems.