February 2026: Focused on release note accuracy and targeted performance improvements across OpenStudio stacks. Added explicit changelog entries for EV charging and battery resilience bug fixes in the OpenStudio-HPXML repo, and refactored schedule type key handling to use emplace_back for improved performance and clarity in CoilCoolingWaterPanelRadiant.

January 2026 performance summary: Focused on unit multiplier support, resilience accuracy, and scheduling enhancements across HPXML and OpenStudio. Delivered unit multiplier integration in resilience calculations for HPXML (multiplying eff_discharge_power and battery losses and exposing an output meter), added a critical load custom meter, and refined whole-building timeseries reporting to use BuildingID with updated tests. Established a unit multiplier testing workflow in CI to ensure batteries with unit multipliers are exercised in tests, and advanced Coil Cooling Water Panel radiant scheduling with new tests in OpenStudio. These changes enhance accuracy of resilience metrics, enable scalable unit-aware modeling, and improve testability and traceability for business decisions.

December 2025 Monthly Summary: Focused on robustness, data fidelity, and EV readiness across NREL/OpenStudio and NREL/OpenStudio-HPXML. Major features delivered include halted-workflow protection for OpenStudio translations (preventing runs and saves during halted states with clearer logs), an EMS architecture refactor and new vehicle charging/discharging programs with gating and early-exit logic, expanded testing for Water Heater Heat Pump Wrapped Condenser to improve EnergyPlus reliability, data model enhancements for window/shading attributes (insect screens, storm windows, interior/exterior shading, skylight IDs), and EV modeling safety improvements with whole-building vehicle validation and example HPXML scenarios. Major bugs fixed include preventing translation/save during halted workflows and fixes for schedule files lacking electric_vehicle column. Overall impact: improved reliability, data fidelity, and scalability of energy models, enabling faster validation cycles and better support for EV-enabled building simulations. Technologies demonstrated: EnergyPlus/HPXML translation, EMS modularization, test-driven development, CI/test automation, and data-attribute modeling.

Month: 2025-11. This period delivered targeted improvements across two repositories to improve stability, numerical reliability, validation, and test reliability, translating to tangible business value for energy modeling workflows and release readiness. Key features delivered and major fixes: - EnergyPlus 25.2.0 release: updated to 25.2.0-RC2 and aligned platform-specific hashes/build metadata in CMake, enabling a cleaner release boundary and consistent builds. (commits a34aa43d46c206c3bd3e3de8b70273b7ffa7950e; 5a3b947b4bfd9d6758fc80f43bf055d73feec1f2) - Nominal cooling capacity fix: data type upgrade to double with numeric 0 in place of 'Autosize' to preserve behavior and improve numerical reliability. (commit fc70c4f98e4321e6ec3c62057c7364ef4e1df6ee) - Code quality and test reliability for model object initialization: encapsulation improvements by making SiteGround constructors protected; updated SiteGroundTemperatureShallow construction to rely on a unique model object; tests updated to depend on a single model object retrieval path for stability. (commits c9cf9631a00fccbed22ebaec3a6be6b359db59bf; dcc5cc92d6411ce5367c191931b6d775abf0e04e; f287e4cf692ea612fecbb325969bc3b7492bc2c7) HPXML-related improvements: - Electric Panel headroom robustness and HPXML validation improvements: ensure headroom never negative, broaden validation coverage, and update related tests and documentation; including outputs docs updates. (commits dc94dcaa955b5df70cc209943568004897ba8b8a; ebcb5061c9c08d5c5c1adda0984741b97f38c428; 624d2e7e2379f8a0ee8f981d240356d7f4ffeb38; 579bd6c86d478a0011399cc163a1c0c124f75991; d02e92cef4ca0b9e0c59e4c63b620d6db8b3380d; f20e3ae2b9e5ae773cce698e5b3014150d07810a) Overall impact and business value: - Increased release readiness and stability across core energy modeling workflows, reducing production risk and support load. - Improved numerical reliability in critical capacities, leading to more predictable simulations and data integrity. - Robust test suite and encapsulation improvements that lower flakiness and enable safer refactors in future cycles. - Documentation and validation enhancements that improve user trust and model transparency. Technologies/skills demonstrated: - CMake/build metadata management and versioning; platform-hash handling. - Object-oriented refactoring and encapsulation in C++ (SiteGround constructors, unique object retrieval). - Test reliability engineering and updated expectations to reduce brittleness. - HPXML validation integration and documentation alignment.

Monthly summary for NREL/OpenStudio (2025-10). Focused on delivering validated enhancements to ZoneHVAC and sizing workflows, expanding test coverage, and tightening model/IDD alignment to support new fields and business requirements. Key outcomes include expanded validation tests, improved data model consistency, and documented changes to enable faster QA and release readiness.

September 2025 performance summary for NREL/OpenStudio and NREL/OpenStudio-HPXML: Delivered high-impact features enhancing efficiency, modeling fidelity, and maintainability, while strengthening test coverage and data translation capabilities. Key work includes enabling EconomizerLockout by default for HeatExchangerDesiccantBalancedFlow to improve energy efficiency and prevent undesirable operation during economizer cycles; updating EnergyPlus IDD for HVAC sizing and performance with new fields; integrating ZoneHVAC:IdealLoadsAirSystem fuel-efficiency fields and translation support; advancing robust garage geometry/footprint calculations with extensive tests and warnings; and implementing a continuous Viridis color scale for comparison visualizations, with fixes to color indexing. Overall, these efforts improve system-level energy performance, model reliability, and user-facing visualization quality.

August 2025 (NREL/OpenStudio) monthly summary focusing on delivering features, fixing critical issues, and strengthening validation and release quality. This period emphasized CI automation, expanded data model/IDD coverage, and enhanced validation rules to improve reliability and business value.

July 2025 performance summary for NREL/OpenStudio and NREL/OpenStudio-HPXML. Delivered features improving modeling accuracy and reliability, strengthened test coverage and infrastructure, and laid groundwork for the OpenStudio 3.10.1 upgrade. Results include more robust defaults, deterministic data handling, reliable weather/EPW processing, and expanded test scaffolding, translating to faster, more dependable energy model generation and fewer CI regressions.

June 2025 highlights: Delivered critical data quality and usability improvements in NREL/OpenStudio-HPXML, focusing on baseline data integrity, output clarity, and validation reliability. These changes reduce input data gaps, improve engineer productivity, and tighten the HPXML→OpenStudio workflow. Also advanced maintainability with internal refactorings and CI/doc updates that lay groundwork for faster iterations.

May 2025 performance highlights across NREL/OpenStudio-HPXML and NREL/OpenStudio. Delivered groundwork for electric panel opt-in, expanded test coverage for panel outputs and defaults, aligned sample data, and implemented data-model adjustments (real home mapping, EV charger defaults). Enhanced breaker space options and API clarity, extended branch circuit capabilities with pre-simulation output handling and validation improvements, and refreshed documentation and release notes. These changes increase configurability, improve data integrity, and reduce risk of misconfiguration for downstream users and validators.

April 2025: Delivered maintainability and robustness improvements across NREL/OpenStudio and NREL/OpenStudio-HPXML. Key outcomes include test suite and model code cleanup reducing unnecessary checks, a bug fix and test for timeseries handling when frequency is 'none' with user-defined outputs (ensuring nil handling and proper errors), and HPXML sample data updates to reflect repository changes. These efforts improve CI reliability, reduce maintenance costs, and provide clearer, error-resilient behavior for users.

March 2025 performance summary for OpenStudio-HPXML and OpenStudio repositories. Delivered structured, business-focused improvements across HPXML and OpenStudio workstreams, emphasizing modeling correctness, automation, and compatibility with EnergyPlus. Key outcomes include standardized HPXML electrical data model/schema, Real Homes integration with test coverage, EV/garage load modeling defaults, HVAC header propagation for mass flow rate calculations, and CoilSystemCoolingWater integration with forward translation plus EnergyPlus RC1 compatibility.

February 2025 performance summary: Expanded testing coverage, stability improvements, and documentation enhancements across the OpenStudio family, with focused feature enrichments in ft tests, reliability fixes in HPXML scheduling, and documentation/build-process stabilization in EnergyPlus. The work enabled more accurate energy modeling, safer releases, and clearer guidance for users. Key features delivered - NREL/OpenStudio: Expanded and updated the new ft test to increase coverage; refactored coil-system tests by separating coilsystem cooling water HX assisted ft into without unitary and coil system configurations; added FT tests and model tests; introduced support for field Density Basis in ZoneVentilationDesignFlowRate; updated FT feature scope and test assets; multiple commits including test expansion and feature refinements; version bumps across related projects. - NREL/OpenStudio-HPXML: Schedule Unavailable Periods Handling — improved outage rules handling for short periods (1–3 outages) with unit tests and documentation refinements; Simulation Control Temperature Capacitance Multiplier Type updated from String to Double for precise transient calculations. - NREL/EnergyPlus: Documentation Navigation and Layout Enhancements to improve TOC depth, cross-references, and figure numbering; Documentation Build Process Stabilization to ensure robust local and Read the Docs builds and correct Python interpreter usage. Major bugs fixed - OpenStudio: Fix ft test failures; widespread typo fixes across codebase and build (cmakelists and new ft); special-case handling improvements for coilsystem ft on the plant loop branch; ongoing FT test fixes and updates. - HPXML: Refined unavailable period rules with test coverage; updated docs and changelog; added unit tests demonstrating fixes. - EnergyPlus: Stabilization improvements for documentation build process. Overall impact and accomplishments - Substantial increase in test coverage and stability across core modeling components, leading to more reliable releases and faster validation cycles. - Improved modeling accuracy and configurability (e.g., density basis, non-dx varspeed scenarios) and better handling of edge cases (coil systems, plant loop branches). - Clearer documentation and more robust build pipelines reduce onboarding time and maintenance burden for contributors. Technologies and skills demonstrated - Test automation and expansion (ft tests, model tests), test-driven enhancements, and test configuration management. - Code quality improvements (typo fixes, formatting) and refactoring to improve maintainability. - System-level changes across HVAC domains (coil systems, density basis, varspeed coils) and data modeling (IDD updates). - Documentation best practices, build pipeline stabilization, and release alignment via version bumps across multiple repositories.

January 2025 was marked by substantial translation refinements, data-model enhancements, and test-coverage expansions across OpenStudio and HPXML, delivering measurable business value through improved modeling fidelity, maintainability, and validation. Key features were implemented with a focus on accurate EnergyPlus translations, robust object management, and clearer panel/demand data flows, while critical tests and documentation were upgraded to support reliability and future changes.

December 2024 performance summary for NREL OpenStudio family. Delivered substantial business value through feature enhancements, extensible framework improvements, and targeted test/data reliability work across OpenStudio and OpenStudio-HPXML. Achievements include new Python plugin searchpaths support and IDD integration, expansion of the extensible framework (constructors, groups, tests, and destructor override), the introduction of bore hole top depth as a required IDD field, and significant CI/build/test/data updates to improve validation, formatting, and data fidelity. HPXML HVAC configuration tests were broadened, defaults refined, and documentation and sample data expanded to improve correctness and user guidance. Together these efforts increase model accuracy, configurability, maintainability, and development velocity, reducing risk and accelerating plugin adoption and validation workflows.

November 2024 performance summary for NREL/OpenStudio-HPXML: Key features delivered: - HPXML input capacity defaults and methods: introduced and refined input capacity handling (stubs and transitions to input capacity), cleaned up input_capacity HPXML methods, and updated power calculations for air handler and pump to leverage capacity-based metrics. Also added utilization of blower fan, airflow cfm, and electric auxiliary energy in power calculations where applicable. - Panel loads defaulting and validation: strengthened robustness by validating system types and avoiding defaults when load type is none. - Mechanical ventilation defaulting and fan power handling: updated defaulting behavior for mechanical ventilation and added a workaround for missing defaulted ventilation fan power. - Tests, sample data, and documentation updates: aligned test samples and documentation with new power arguments and defaults (breaker spaces, pool/spa defaults, and HPXML resource docs). - Schema validation and changes: improved schema validation, assigned empty system_idrefs where needed, and updated field names with TODOs resolved. - Testing improvements and test updates: expanded hvac/wh tests, updated expected values, and enhanced debugging output (breaker-space reporting by load type). - Hardcoded panel load output names: ensured consistent naming for stability in reporting. - HVAC capacity methods and COP enhancements: stubbed water heater input capacity, added methods for hpwh COP and related watts, and refined COP handling in dx scenarios. - Capacity/regressions fix: moved away from regression-based capacity logic to more robust approaches. - Panel calculation types improvements: enabled multiple panel calculation types, updated inputs/outputs docs, ensured reporting of only requested types, and modularized panel outputs. - Clarifications and COP handling: clarified ventless dryer interpretation and temporary COP handling strategies. - Testing and refactoring improvements: ongoing refactoring and expanded configuration testing for HVAC setups. Major bugs fixed: - Panel loads: added error checking on system types and prevented defaulting when type is none. - Mechanical ventilation: fixed defaulting issues and added workaround for missing vent fan power defaults. - Test and data alignment: updated samples and defaults to reflect new power arguments and breaker spaces, reducing false positives in tests. Overall impact and accomplishments: - Increased modeling robustness and accuracy forHPXML-driven simulations, reducing post-merge defects and improving reliability of energy-performance results for projects using OpenStudio-HPXML. - Broadened test coverage and data validation, enabling faster iteration and safer deployments. - Strengthened documentation and schema consistency, improving developer onboarding and user guidance. Technologies/skills demonstrated: - Ruby-based HPXML domain modeling, schema validation, and capacity-focused calculations. - Test automation, hvac/wh test expansion, and data-driven sample updates. - Refactoring and documentation practices, with clear code-path improvements for panel and hvac calculations.

October 2024 performance summary focusing on delivering business value through improved modeling accuracy and expanded testing coverage across HPXML/OpenStudio and OpenStudio repos. Key outcomes include enhancements to HPXML/OpenStudio electric panel load modeling: validation improvements, handling of defaulted panel loads, exclusion of shared water heating from panel loads, refined heat pump backup simultaneity logic, support for low-load scenarios, Part A refinements, argument consolidation, and the introduction of a new Mech Vent load type to improve granularity and accuracy in residential electrical load modeling. In OpenStudio, expanded UniterySystemPerformanceMultispeed testing coverage and data model improvements: more test scenarios, standardizing multispeed coils, validating speed-related data fields, stage and unitary flow handling, and ensuring better translation to EnergyPlus IDF. Collectively these efforts improve model accuracy, reliability, QA coverage, and enable better business decisions by delivering more accurate energy-use predictions and interoperable data models.

July 2024 performance summary for NREL/OpenStudio. Delivered feature-level robustness enhancements and API modernization for Epw-related components, expanded test coverage, and prepared release documentation to support upgrades. Result: more robust data handling, reduced regression risk, and improved maintainability across EpwFile and EpwDesignCondition code paths.

Month: 2024-04. NREL/OpenStudio: Implemented EPW Incomplete Design Header Test Coverage. Added an EPW file with an incomplete design header row and a test case to validate handling of incomplete design conditions in EPW files. Commits: 875e34896e4e917d42b2b4a296ddec1f2b9ac2fe; 90e52be59fbf2bac66800b9699174b2223bcf74e. These changes strengthen regression testing and edge-case handling for EPW parsing, reducing risk of incorrect design data influencing results.