NREL/EnergyPlus
Oct 2024 – Oct 2025
12 Months active
Languages Used
C++FortranLaTeXTeXMarkdowniddCSVIDF
Technical Skills
Bug FixingEnergy ModelingSoftware DevelopmentBug FixC++C++ Development
Michael J. Witte
PROFILE
Michael J. Witte
Over the past year, Michael Witte engineered core enhancements and stability improvements for the NREL/EnergyPlus repository, focusing on energy modeling, reporting accuracy, and simulation reliability. He modernized plant loop and ventilation calculations, expanded district heating and chiller system features, and improved output formatting and data integrity. Using C++ and Fortran, Michael refactored legacy code, introduced dynamic logic for sizing and control, and strengthened test coverage with robust unit testing. His work addressed edge-case failures, streamlined configuration management, and aligned outputs with evolving standards, resulting in more maintainable code and higher-fidelity simulations for building energy and HVAC system analysis.
Overall Statistics
Feature vs Bugs
55%Features
Repository Contributions
228Total
Bugs
49
Commits
228
Features
61
Lines of code
18,921
Activity Months12
Your Network
32 peopleSame Organization
@gard.com1
Work History
October 2025
25 Commits • 9 Features
Oct 1, 2025October 2025 performance highlights for NREL/EnergyPlus: Key features delivered and major fixes delivered, with a focus on improving report accuracy, data integrity, and output quality.
25 Commits • 9 Features
Oct 1, 2025October 2025 performance highlights for NREL/EnergyPlus: Key features delivered and major fixes delivered, with a focus on improving report accuracy, data integrity, and output quality.
October 2025
September 2025
36 Commits • 10 Features
Sep 1, 2025September 2025 performance summary for NREL/EnergyPlus: Focused on stability, test coverage, and output quality. Delivered targeted bug fixes, expanded unit tests, and laid groundwork for richer JSON/SQLite outputs and consistent report formatting. These efforts improved reliability of core calculations and reporting, reduced build/test noise, and positioned the project for easier future extension.
September 2025
36 Commits • 10 Features
Sep 1, 2025September 2025 performance summary for NREL/EnergyPlus: Focused on stability, test coverage, and output quality. Delivered targeted bug fixes, expanded unit tests, and laid groundwork for richer JSON/SQLite outputs and consistent report formatting. These efforts improved reliability of core calculations and reporting, reduced build/test noise, and positioned the project for easier future extension.
August 2025
24 Commits • 7 Features
Aug 1, 2025August 2025 monthly summary for NREL/EnergyPlus focusing on delivering enhanced energy modeling features, stabilizing test infrastructure, and improving code quality. The month includes substantial feature work across the core EnergyPlus data model, improved reporting, and alignment of I/O references with implementation details, alongside rigorous unit-test stabilization.
24 Commits • 7 Features
Aug 1, 2025August 2025 monthly summary for NREL/EnergyPlus focusing on delivering enhanced energy modeling features, stabilizing test infrastructure, and improving code quality. The month includes substantial feature work across the core EnergyPlus data model, improved reporting, and alignment of I/O references with implementation details, alongside rigorous unit-test stabilization.
August 2025
July 2025
9 Commits • 4 Features
Jul 1, 2025July 2025 performance summary: delivered key reporting and reliability improvements for EnergyPlus, with a focus on accurate central-plant capacity reporting, expanded heat-recovery visibility, and code-quality enhancements that improve maintainability and safety. These changes bolster design decision support, reduce runtime risks, and improve user-facing warnings.
July 2025
9 Commits • 4 Features
Jul 1, 2025July 2025 performance summary: delivered key reporting and reliability improvements for EnergyPlus, with a focus on accurate central-plant capacity reporting, expanded heat-recovery visibility, and code-quality enhancements that improve maintainability and safety. These changes bolster design decision support, reduce runtime risks, and improve user-facing warnings.
June 2025
4 Commits • 3 Features
Jun 1, 2025June 2025 monthly summary for NREL/EnergyPlus focused on strengthening plant loop operation robustness, aligning outputs with EnergyPlus 25.2.0, and improving code readability and maintainability. Key features delivered include: - Plant loop operation improvements: dynamic scan of supply-side components to determine heating or cooling capabilities, replacing reliance solely on plant sizing objects. - Robust sizing default: when no plant sizing object is present, default to NonCoincident sizing to avoid misclassification. - Output reporting updates for EnergyPlus 25.2.0: updated Equipment Summary Report, ensured consistent sizing reporting for PlantLoop and CondenserLoop sub-tables, and added design temperature and capacity columns. - Code cleanup: braces for if statements in Base.cc and PlantManager.cc to improve readability with no functional changes. Major bugs fixed (robustness and reporting): - Edge-case robustness: defaulting to NonCoincident when sizing object is missing to prevent incorrect size logic in plant loop operation. - Output reporting consistency: alignment with 25.2.0 rules, ensuring consistency across PlantLoop and CondenserLoop subtables and new design temperature/capacity columns. - Minor readability fixes that reduce risk of misinterpretation in future edits. Overall impact and accomplishments: - Improved simulation accuracy and reliability for plant sizing and energy reporting, reducing risk of misinterpretation in energy calculations and ensuring stakeholders receive consistent, up-to-date outputs. Maintains EnergyPlus alignment with current versioning and design-temperature conventions. Technologies/skills demonstrated: - C++ code changes, dynamic analysis logic, and robust edge-case handling; data reporting improvements; versioned output rule updates; and maintainability-focused code cleanups.
4 Commits • 3 Features
Jun 1, 2025June 2025 monthly summary for NREL/EnergyPlus focused on strengthening plant loop operation robustness, aligning outputs with EnergyPlus 25.2.0, and improving code readability and maintainability. Key features delivered include: - Plant loop operation improvements: dynamic scan of supply-side components to determine heating or cooling capabilities, replacing reliance solely on plant sizing objects. - Robust sizing default: when no plant sizing object is present, default to NonCoincident sizing to avoid misclassification. - Output reporting updates for EnergyPlus 25.2.0: updated Equipment Summary Report, ensured consistent sizing reporting for PlantLoop and CondenserLoop sub-tables, and added design temperature and capacity columns. - Code cleanup: braces for if statements in Base.cc and PlantManager.cc to improve readability with no functional changes. Major bugs fixed (robustness and reporting): - Edge-case robustness: defaulting to NonCoincident when sizing object is missing to prevent incorrect size logic in plant loop operation. - Output reporting consistency: alignment with 25.2.0 rules, ensuring consistency across PlantLoop and CondenserLoop subtables and new design temperature/capacity columns. - Minor readability fixes that reduce risk of misinterpretation in future edits. Overall impact and accomplishments: - Improved simulation accuracy and reliability for plant sizing and energy reporting, reducing risk of misinterpretation in energy calculations and ensuring stakeholders receive consistent, up-to-date outputs. Maintains EnergyPlus alignment with current versioning and design-temperature conventions. Technologies/skills demonstrated: - C++ code changes, dynamic analysis logic, and robust edge-case handling; data reporting improvements; versioned output rule updates; and maintainability-focused code cleanups.
June 2025
May 2025
18 Commits • 2 Features
May 1, 2025May 2025 monthly summary for NREL/EnergyPlus focusing on Outdoor Air (OA) calculation modernization and related QA work. Delivered centralized OA flow calculations, IAQ method support, and a refactor to DS Outdoor Air data objects, enabling new OA calculation pathways for zones and spaces to improve ventilation accuracy and maintainability. Expanded OA data modeling with SpaceList support and robust test scaffolding. Improved test reliability for Internal Heat Gains and space allocation in multi-space zones, and performed targeted cleanup to reduce noise in results and diffs. These changes enhance ventilation control fidelity, maintainability, and overall energy/IAQ performance while enabling faster iteration on OA-related features.
May 2025
18 Commits • 2 Features
May 1, 2025May 2025 monthly summary for NREL/EnergyPlus focusing on Outdoor Air (OA) calculation modernization and related QA work. Delivered centralized OA flow calculations, IAQ method support, and a refactor to DS Outdoor Air data objects, enabling new OA calculation pathways for zones and spaces to improve ventilation accuracy and maintainability. Expanded OA data modeling with SpaceList support and robust test scaffolding. Improved test reliability for Internal Heat Gains and space allocation in multi-space zones, and performed targeted cleanup to reduce noise in results and diffs. These changes enhance ventilation control fidelity, maintainability, and overall energy/IAQ performance while enabling faster iteration on OA-related features.
April 2025
27 Commits • 8 Features
Apr 1, 2025April 2025 focused on consolidating equipment reporting, strengthening sizing/design level infrastructure, and expanding reporting while maintaining code quality. Key work spanned Equipment Summary reorganization, enum-driven sizing/design level changes, UI/reporting improvements for EvapFluidCooler, and robust testing/cleanup to improve reliability and maintainability.
27 Commits • 8 Features
Apr 1, 2025April 2025 focused on consolidating equipment reporting, strengthening sizing/design level infrastructure, and expanding reporting while maintaining code quality. Key work spanned Equipment Summary reorganization, enum-driven sizing/design level changes, UI/reporting improvements for EvapFluidCooler, and robust testing/cleanup to improve reliability and maintainability.
April 2025
March 2025
19 Commits • 2 Features
Mar 1, 2025March 2025: Delivered robust documentation updates for EnergyPlus IDD and output reporting, including clarifications for SpaceHVAC references. Stabilized MechanicalVentilation by enforcing at least one zone, added Do Space Heat Balance consistency and sizing guards, and advanced Heat Recovery with a refactor (AirToAir_Generic renamed to AirToAir_SensAndLatent) plus enhanced reporting and unit tests. The work encompassed extensive test coverage and multiple commits across documentation, core logic, and reporting components, reducing runtime errors and improving maintainability and accuracy of simulations.
March 2025
19 Commits • 2 Features
Mar 1, 2025March 2025: Delivered robust documentation updates for EnergyPlus IDD and output reporting, including clarifications for SpaceHVAC references. Stabilized MechanicalVentilation by enforcing at least one zone, added Do Space Heat Balance consistency and sizing guards, and advanced Heat Recovery with a refactor (AirToAir_Generic renamed to AirToAir_SensAndLatent) plus enhanced reporting and unit tests. The work encompassed extensive test coverage and multiple commits across documentation, core logic, and reporting components, reducing runtime errors and improving maintainability and accuracy of simulations.
February 2025
38 Commits • 11 Features
Feb 1, 2025February 2025 — NREL/EnergyPlus: Implemented density options for ZoneInfiltration and ZoneVentilation, added new outputs for infiltration and ventilation, and extended unit tests to improve coverage. Alongside feature work, the month included targeted bug fixes (ACH calculations, output naming regressions, zero-zone handling) and documentation/formatting improvements to support maintainability and downstream integrations. The work enhances reporting accuracy, enables density-based design flavors, and strengthens testability and stability.
38 Commits • 11 Features
Feb 1, 2025February 2025 — NREL/EnergyPlus: Implemented density options for ZoneInfiltration and ZoneVentilation, added new outputs for infiltration and ventilation, and extended unit tests to improve coverage. Alongside feature work, the month included targeted bug fixes (ACH calculations, output naming regressions, zero-zone handling) and documentation/formatting improvements to support maintainability and downstream integrations. The work enhances reporting accuracy, enables density-based design flavors, and strengthens testability and stability.
February 2025
January 2025
14 Commits • 3 Features
Jan 1, 2025January 2025 — Delivered Space boundary conditions support and reporting for NREL/EnergyPlus, including IDD updates and Envelope Summary enhancements to expose Space and Zone data; updated documentation and outputs. Implemented robust surface boundary condition handling and space/zone assignment fixes (including unentered adjacent spaces and inter-space surfaces). Switched to dynamic time-step indexing to improve simulation timing reliability. Expanded unit tests for UnitarySystem and boundary conditions, including tests for Space/Zone outside defined zones/spaces. Completed code quality and formatting cleanup to improve maintainability. This work enhances simulation accuracy, enriches reporting, and reduces regression risk through stronger test coverage.
January 2025
14 Commits • 3 Features
Jan 1, 2025January 2025 — Delivered Space boundary conditions support and reporting for NREL/EnergyPlus, including IDD updates and Envelope Summary enhancements to expose Space and Zone data; updated documentation and outputs. Implemented robust surface boundary condition handling and space/zone assignment fixes (including unentered adjacent spaces and inter-space surfaces). Switched to dynamic time-step indexing to improve simulation timing reliability. Expanded unit tests for UnitarySystem and boundary conditions, including tests for Space/Zone outside defined zones/spaces. Completed code quality and formatting cleanup to improve maintainability. This work enhances simulation accuracy, enriches reporting, and reduces regression risk through stronger test coverage.
November 2024
13 Commits • 2 Features
Nov 1, 2024Monthly summary for 2024-11 (NREL/EnergyPlus): Delivered key features for District Heating improvements and chiller/unitary system robustness, with expanded test coverage and documentation updates. Major bug fixes include DistrictHeating:Water and related data/documentation cleanups; added support for DistrictHeating:Steam and corrected data structures (e.g., PollutionModule array fix). Achievements include enhanced typing and reporting for district heating, improved unitary and EIR chiller reliability through targeted tests, and extensive code cleanup. Impact: higher fidelity district heating modeling, more robust chiller/unitary simulations, reduced risk of edge-case failures, and improved maintainability. Technologies/skills demonstrated: C++ development, unit testing, test-driven validation, documentation and IDD updates, and formatting/cleanup.
13 Commits • 2 Features
Nov 1, 2024Monthly summary for 2024-11 (NREL/EnergyPlus): Delivered key features for District Heating improvements and chiller/unitary system robustness, with expanded test coverage and documentation updates. Major bug fixes include DistrictHeating:Water and related data/documentation cleanups; added support for DistrictHeating:Steam and corrected data structures (e.g., PollutionModule array fix). Achievements include enhanced typing and reporting for district heating, improved unitary and EIR chiller reliability through targeted tests, and extensive code cleanup. Impact: higher fidelity district heating modeling, more robust chiller/unitary simulations, reduced risk of edge-case failures, and improved maintainability. Technologies/skills demonstrated: C++ development, unit testing, test-driven validation, documentation and IDD updates, and formatting/cleanup.
November 2024
October 2024
1 Commits
Oct 1, 2024October 2024 monthly summary for NREL/EnergyPlus. Focused on stabilizing chiller control behavior and ensuring accurate energy modeling. Key outcome: a bug fix preventing unintended chiller shutdown when condenser flow is zero in other chillers; ensures load is set to zero and standby power is applied when condenser mass flow falls below the tolerance. Applied across multiple chiller models to ensure consistency and reliability. Commit: c894587d9257067cc05f15681daa0142f8c1fe4d. Impact: reduces downtime risk, improves energy consumption predictability, and enhances model fidelity for engineering decisions.
October 2024
1 Commits
Oct 1, 2024October 2024 monthly summary for NREL/EnergyPlus. Focused on stabilizing chiller control behavior and ensuring accurate energy modeling. Key outcome: a bug fix preventing unintended chiller shutdown when condenser flow is zero in other chillers; ensures load is set to zero and standby power is applied when condenser mass flow falls below the tolerance. Applied across multiple chiller models to ensure consistency and reliability. Commit: c894587d9257067cc05f15681daa0142f8c1fe4d. Impact: reduces downtime risk, improves energy consumption predictability, and enhances model fidelity for engineering decisions.
Activity
Loading activity data...
Quality Metrics
Correctness91.6%
Maintainability91.2%
Architecture86.6%
Performance86.0%
AI Usage20.2%
Skills & Technologies
Programming Languages
C++CSVFortranIDFLaTeXMarkdownRVITeXidd
Technical Skills
Bug FixBug FixingBuilding Energy ModelingBuilding Energy SimulationBuilding Performance SimulationC++C++ DevelopmentCode CleanupCode DocumentationCode FormattingCode ModernizationCode OptimizationCode OrganizationCode RefactoringCode Reversion
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline