Trial / Demo
Zero Envy formulated a robust decarbonization strategy aimed at achieving net zero carbon emissions by 2035. Leveraging the capabilities of IESVE software, including ModelIT, ApacheHVAC and the VEScripts Python API, they developed eight targeted solutions to meet its carbon-neutral goals.
CalPERS “Lincoln Plaza North” is an existing government office building in Sacramento, California. Zero Envy formulated a robust decarbonization strategy aimed at achieving net zero carbon emissions by 2035. Leveraging the capabilities of IESVE software, including ModelIT, ApacheHVAC and the VEScripts Python API, they developed eight targeted solutions to meet its carbon-neutral goals.
Zero Envy was hired as part of a team to develop a decarbonization strategy to reach net zero carbon emissions (scope 1 and 2) by 2035. This included an ASHRAE Level II Energy Audit, a Digital Twin calibrated energy model of the existing building and decarbonization analysis.
They calibrated the Digital Twin energy model to match actual building energy use over a year in order to provide meaningful decarbonization strategies. They conducted a rigorous ASHRAE Level II energy audit to gather key inputs for the energy model, including a site visit, existing design document/specs review and energy usage analysis. They also performed an in-depth analysis of Building Management System (BMS) trend data to accurately model the building system controls.
Figure 1: Building aerial photographs and Energy Model Geometry
The mechanical system primarily consists of a variable volume primary air system and several smaller Air Handling Units (AHU’s) serving dedicated spaces. Constant volume fan terminal units, VAV terminals, fan-powered mixing boxes, and a combination of those are located on each floor to provide cooling and heating options.
Figure 2: Energy Model HVAC Systems
The energy model was calibrated to match monthly electricity and natural gas data with utility bills, following ASHRAE Guideline 14 using CVRMSE (Coefficient of the Variation of the Root Mean Square Error) and NMBE (Normalized Mean Bias Error) metrics. The calculated CVRMSE values were 3.1% for electricity and 12.3% for natural gas, and the NMBE values were 2.1% and 1.5%, respectively - both within required limits.
Figure 3: Comparison of calibrated results and actual building energy usage
Decarbonization Analysis
The calibrated model was used to evaluate decarbonization and energy conservation measures. In total, 15 measures were analyzed and eight were included in the recommended strategy. The measures covered lighting systems, HVAC systems, domestic hot water systems and miscellaneous loads such as the kitchen equipment. A few examples of the recommended strategies are described below:
Figure 4: Fan curve comparison and curve fitting
Figure 5: Central plant and heat recovery potential analysis using Python
Results with Eight Targeted Solutions
The graph below illustrates a clear roadmap to achieve the project's carbon-neutral goal by 2035, year by year, highlighting the eight measures and their respective implementation timelines:
Figure 6: Path to net carbon
In Summary
Zero Envy played a key role in formulating a robust decarbonization strategy aimed at achieving net zero carbon emissions by 2035. Leveraging the capabilities of IESVE, including ModelIT, ApacheHVAC and the VEScripts Python API, the team developed eight targeted solutions, which collectively provided a well-defined roadmap for the project to successfully meet its ambitious carbon-neutral goals.
"Zero Envy's strategic approach and IESVE’s advanced capabilities enabled a clear and achievable pathway to meet ambitious 2035 net zero carbon targets. The eight solutions provided a robust framework for Lincoln Plaza North’s decarbonization journey."
Yiyu Chen, Zero Envy
