NREL/EnergyPlus
Jan 2025 – Jul 2025
5 Months active
Languages Used
C++MarkdownTeX
Technical Skills
DocumentationEnergy ModelingHVAC SystemsSoftware DesignTechnical DocumentationTechnical Writing
Lixing Gu
PROFILE
Lixing Gu
Worked on the NREL/EnergyPlus repository to design and implement advanced duct loss modeling features for HVAC energy simulations. Over five months, developed new DuctLoss objects and enhanced input processing, enabling accurate modeling of conduction, leakage, and makeup air losses in single air loops. Leveraged C++ and domain expertise in energy modeling to refactor code, improve documentation, and streamline input requirements, supporting maintainability and usability. Integrated feedback from design reviews, updated technical documentation in Markdown and LaTeX, and validated models through rigorous testing. These contributions improved simulation accuracy, reduced onboarding complexity, and supported more reliable building energy performance analysis in EnergyPlus.
Overall Statistics
Feature vs Bugs
100%Features
Repository Contributions
17Total
Bugs
0
Commits
17
Features
5
Lines of code
7,456
Activity Months5
Your Network
39 peopleSame Organization
@fsec.ucf.edu2
Shared Repositories
37
Alex SwindlerMember
Alex SwindlerMember
Amir RothMember
Amir RothMember
Amir RothMember
Amir RothMember
Bereket NigusseMember
brianlballMember
Dominik WójtMember
Work History
July 2025
1 Commits • 1 Features
Jul 1, 2025July 2025 monthly summary for NREL/EnergyPlus focused on refining the Duct Loss Modeling feature to improve accuracy, usability, and maintainability of HVAC simulations.
1 Commits • 1 Features
Jul 1, 2025July 2025 monthly summary for NREL/EnergyPlus focused on refining the Duct Loss Modeling feature to improve accuracy, usability, and maintainability of HVAC simulations.
July 2025
June 2025
12 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for NREL/EnergyPlus: Delivered DuctLoss: Conduction, Leakage, and Makeup Air modeling feature; implemented new DuctLoss objects, input processing, and energy loss calculations; mapped components (splitters/mixers); added validations for AirLoopHVAC; updated tests and docs. Also fixed a set of bugs and improved code quality with clang-format and test cleanups. This work improves modeling accuracy, robustness, and maintainability, reducing long-term maintenance risk and enabling more reliable energy simulations.
June 2025
12 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for NREL/EnergyPlus: Delivered DuctLoss: Conduction, Leakage, and Makeup Air modeling feature; implemented new DuctLoss objects, input processing, and energy loss calculations; mapped components (splitters/mixers); added validations for AirLoopHVAC; updated tests and docs. Also fixed a set of bugs and improved code quality with clang-format and test cleanups. This work improves modeling accuracy, robustness, and maintainability, reducing long-term maintenance risk and enabling more reliable energy simulations.
March 2025
1 Commits • 1 Features
Mar 1, 2025March 2025 performance summary for NREL/EnergyPlus focusing on enhancing the NFP duct model for moisture calculations and simplifying leakage accounting. Implemented a humidity ratio field and leakage localization within the NFP duct model, and removed the separate supply leak calculation by integrating it into system loads. This reduces model complexity while improving moisture accuracy, supporting more reliable energy simulations and decision-making.
1 Commits • 1 Features
Mar 1, 2025March 2025 performance summary for NREL/EnergyPlus focusing on enhancing the NFP duct model for moisture calculations and simplifying leakage accounting. Implemented a humidity ratio field and leakage localization within the NFP duct model, and removed the separate supply leak calculation by integrating it into system loads. This reduces model complexity while improving moisture accuracy, supporting more reliable energy simulations and decision-making.
March 2025
February 2025
1 Commits • 1 Features
Feb 1, 2025February 2025 monthly summary for NREL/EnergyPlus focusing on documentation and design governance improvements that enable safer and faster downstream implementation of the NFP-DuctModelSingleLoop.
February 2025
1 Commits • 1 Features
Feb 1, 2025February 2025 monthly summary for NREL/EnergyPlus focusing on documentation and design governance improvements that enable safer and faster downstream implementation of the NFP-DuctModelSingleLoop.
January 2025
2 Commits • 1 Features
Jan 1, 2025January 2025 monthly summary for NREL/EnergyPlus focusing on groundwork for model enhancements and documentation improvement. This period concentrated on proposing and documenting a duct model enhancement to better capture conduction losses and duct leakage in single air loops without requiring a full airflow network. The effort culminated in a formal New Feature Proposal (NFP) with defined input objects, modifications to existing inputs, and outlined algorithms for loss calculations. Documentation was updated to incorporate feedback on mass flow handling for supply/return leaks and to retain the Heat Transmittance Coefficient (U-Factor) field, including clarified assumptions and usage examples. Two commits tied to the NFP were recorded: one to upload the NFP and another to update it.
2 Commits • 1 Features
Jan 1, 2025January 2025 monthly summary for NREL/EnergyPlus focusing on groundwork for model enhancements and documentation improvement. This period concentrated on proposing and documenting a duct model enhancement to better capture conduction losses and duct leakage in single air loops without requiring a full airflow network. The effort culminated in a formal New Feature Proposal (NFP) with defined input objects, modifications to existing inputs, and outlined algorithms for loss calculations. Documentation was updated to incorporate feedback on mass flow handling for supply/return leaks and to retain the Heat Transmittance Coefficient (U-Factor) field, including clarified assumptions and usage examples. Two commits tied to the NFP were recorded: one to upload the NFP and another to update it.
January 2025
Activity
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Quality Metrics
Correctness88.2%
Maintainability88.2%
Architecture87.2%
Performance83.6%
AI Usage21.2%
Skills & Technologies
Programming Languages
C++MarkdownTeX
Technical Skills
Array IndexingBug FixC++C++ DevelopmentCode FormattingCode RefactoringDocumentationEnergy ModelingEnergy SimulationEnum HandlingError HandlingFortran (implied by EnergyPlus codebase)HVAC System ModelingHVAC SystemsHVAC Systems Modeling
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