OpenStudio-ERI v1.7.1

OpenStudio-ERI version 1.7.1 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.7.1 uses OpenStudio v3.7.0, EnergyPlus v23.2.0, and HPXML v4.0-rc2. Please visit the OpenStudio-ERI v1.7.0 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

Bugfixes

• Fixes emissions lookup when zip code starts with a zero.

OpenStudio-ERI v1.7.0

OpenStudio-ERI version 1.7.0 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.7.0 uses OpenStudio v3.7.0, EnergyPlus v23.2.0, and HPXML v4.0-rc2. Please visit the OpenStudio-ERI v1.7.0 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

New Features

• Updates to OpenStudio 3.7.0/EnergyPlus 23.2.
• Breaking change: Updates to HPXML v4.0-rc2:
  • HPXML namespace changed from http://hpxmlonline.com/2019/10 to http://hpxmlonline.com/2023/09.
  • Replaces "living space" with "conditioned space", which better represents what is modeled.
  • Replaces PortableHeater and FixedHeater with SpaceHeater.
• HVAC updates:
  • Updated assumptions for variable-speed air conditioners, heat pumps, and mini-splits based on NEEP data. Expect results to change, potentially significantly so depending on the scenario.
  • Updates deep ground temperatures (used for modeling ground-source heat pumps) using L. Xing's simplified design model (2014).
  • Replaces inverse calculations, used to calculate COPs from rated efficiencies, with regressions for single/two-speed central ACs and ASHPs.
• Output updates:
  • Breaking change: Disaggregates "EC_x Vent" and "EC_x Dehumid" from "EC_x L&A" in ERI_Results.csv.
  • Adds "Peak Electricity: Annual Total (W)" output.
• Relaxes requirements for some inputs:
  • SolarAbsorptance and Emittance now only required for exterior walls & rim joists (i.e., ExteriorAdjacentTo=outside).
  • Window/PerformanceClass no longer required (defaults to "residential").
  • Allows above-grade basements/crawlspaces defined solely with Wall (not FoundationWall) elements.
• Adds ZERH Multifamily v2.
• Updates to ZERH Single Family v2 windows SHGC in climate zone 4 through 8.
• Allow JSON output files instead of CSV via a new --output-format JSON commandline argument.

Bugfixes

• Fixes possible "Electricity category end uses do not sum to total" error for a heat pump w/o backup.
• Fixes error if conditioned basement has InsulationSpansEntireSlab=true.
• Fixes error if heat pump CompressorLockoutTemperature == BackupHeatingLockoutTemperature.
• Fixes ground source heat pump fan/pump adjustment to rated efficiency.
• Fixes missing radiation exchange between window and sky.
• Minor HVAC design load calculation bugfixes for foundation walls.
• Fixes nEC_x calculation for a fossil fuel water heater w/ UEF entered.
• Various HVAC sizing bugfixes and improvements.

OpenStudio-ERI v1.6.3

OpenStudio-ERI version 1.6.3 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.6.3 uses OpenStudio v3.6.1, EnergyPlus v23.1.0, and a proposed HPXML v4.0. Please visit the OpenStudio-ERI v1.6.3 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

Bugfixes

• Fixes possible "Sum of energy consumptions do not match total" error for shared water heater w/ FractionDHWLoadServed=0.

OpenStudio-ERI v1.6.2

OpenStudio-ERI version 1.6.2 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.6.2 uses OpenStudio v3.6.1, EnergyPlus v23.1.0, and a proposed HPXML v4.0. Please visit the OpenStudio-ERI v1.6.2 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

Bugfixes

• Fixes incorrect ESRD ceiling U-factor for SFA unit with adiabatic ceiling when using SFNH program.

OpenStudio-ERI v1.6.1

OpenStudio-ERI version 1.6.1 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.6.1 uses OpenStudio v3.6.1, EnergyPlus v23.1.0, and a proposed HPXML v4.0. Please visit the OpenStudio-ERI v1.6.1 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

Bugfixes

• Fixes ZERH Single Family v2 mechanical ventilation fan efficiency to use ASRE instead of SRE.
• Fixes error if describing a wall with WallType/StructuralInsulatedPanel.

OpenStudio-ERI v1.6.0

OpenStudio-ERI version 1.6.0 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.6.0 uses OpenStudio v3.6.1, EnergyPlus v23.1.0, and a proposed HPXML v4.0. Please visit the OpenStudio-ERI v1.6.0 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

New Features

• Updates to OpenStudio 3.6.1/EnergyPlus 23.1.
• Breaking change: CO2e Index results must now be requested through a new optional SoftwareInfo/extension/CO2IndexCalculation/Version input.
• Updates to newer proposed HPXML v4.0:
  • Breaking change: Replaces CeilingFan/Quantity, ClothesWasher/NumberofUnits, and ClothesDryer/NumberofUnits with Count.
  • Breaking change: Replaces PVSystem/InverterEfficiency with PVSystem/AttachedToInverter and Inverter/InverterEfficiency.
• Output updates:
  • Breaking change: Adds End Use: Heating Heat Pump Backup Fans/Pumps (disaggregated from End Use: Heating Fans/Pumps).
  • Breaking change: Replaces Component Load: Windows with Component Load: Windows Conduction and Component Load: Windows Solar.
  • Breaking change: Replaces Component Load: Skylights with Component Load: Skylights Conduction and Component Load: Skylights Solar.
  • Breaking change: Adds Component Load: Lighting (disaggregated from Component Load: Internal Gains).
  • Breaking change: Adds "net" values for emissions; "total" values now exclude generation (e.g., PV).
  • Adds Load: Heating: Heat Pump Backup (heating load delivered by heat pump backup systems).
  • Adds System Use outputs (end use outputs for each heating, cooling, and water heating system); allows requesting timeseries output.
  • All annual load outputs are now provided as timeseries outputs; previously only "Delivered" loads were available.
  • Peak summer/winter electricity outputs are now based on Jun/July/Aug and Dec/Jan/Feb months, not HVAC heating/cooling operation.
• Heat pump enhancements:
  • Allows HeatingCapacityRetention[Fraction | Temperature] optional inputs as a more flexible alternative to HeatingCapacity17F.
  • Allows CompressorLockoutTemperature and BackupHeatingLockoutTemperature as optional inputs; alternatives to BackupHeatingSwitchoverTemperature.
  • Defaults for CompressorLockoutTemperature: 25F for dual-fuel, -20F for mini-split, 0F for all other heat pumps.
  • Defaults for BackupHeatingLockoutTemperature: 50F for dual-fuel, 40F for all other heat pumps.
  • Increased consistency between variable-speed central HP and mini-split HP models for degradation coefficients, gross SHR calculations, etc.
• Duct enhancements:
  • Allows modeling ducts buried in attic loose-fill insulation using Ducts/DuctBuriedInsulationLevel.
  • The duct effective R-value can now be found in the ERI___Home.xml files; it accounts for exterior air film, duct shape, and buried insulation level.
• Allows additional building air leakage inputs (ACH or CFM at user-specified house pressure, Natural CFM, Effective Leakage Area).
• LightingGroup for garage is no longer required if the home doesn't have a garage.
• Weather cache files (*foo-cache.csv) are no longer used/needed.

Bugfixes

• Adds error-checking to ensure that SFA/MF dwelling units have at least one attached wall/ceiling/floor surface.
• Various Manual J HVAC autosizing calculation bugfixes and improvements.
• Ensure that ductless HVAC systems do not have a non-zero airflow defect ratio specified.

OpenStudio-ERI v1.5.2

OpenStudio-ERI version 1.5.2 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.5.2 uses OpenStudio v3.5.0, EnergyPlus v22.2.0, and a proposed HPXML v4.0. Please visit the OpenStudio-ERI v1.5.2 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

New Features

• Adds support for ZERH Single Family v2.
• Updates to ENERGY STAR SFNH Rev 12 and MFNC Rev 03.
• WaterHeatingSystem/RecoveryEfficiency is now an optional input.
• Weather cache file (*-cache.csv) is now optional; if not provided, it will be generated on the fly. Provide the cache file for fastest runtime.
• Provide two decimal places in ENERGY STARS/ZERH CSV output files to better prevent user confusion.

Bugfixes

• Bugfixes for ENERGY STAR and ZERH programs.

OpenStudio-ERI v1.5.1

OpenStudio-ERI version 1.5.1 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.5.1 uses OpenStudio v3.5.0, EnergyPlus v22.2.0, and a proposed HPXML v4.0. Please visit the OpenStudio-ERI v1.5.1 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

Bugfixes

• Fixes incorrect warning about zip code not found in eGRID/Cambium lookup table.
• Fixes error when a non-electric water heater has jacket insulation and the UEF metric is used.

OpenStudio-ERI v1.5.0

OpenStudio-ERI version 1.5.0 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

OpenStudio-ERI v1.5.0 uses OpenStudio v3.5.0, EnergyPlus v22.2.0, and a proposed HPXML v4.0. Please visit the OpenStudio-ERI v1.5.0 documentation for instructions on how to get started, how to connect software tools to the workflow, etc. The full set of US TMY3 weather files can be obtained from here.

New Features

• Updates to OpenStudio 3.5.0/EnergyPlus 22.2.
• Updates to newer proposed HPXML v4.0:
  • Breaking change: Replaces FrameFloors/FrameFloor with Floors/Floor.
  • Breaking change: Floor/FloorType (WoodFrame, StructuralInsulatedPanel, SteelFrame, or SolidConcrete) is a required input.
  • Breaking change: All Ducts must now have a SystemIdentifier.
  • Breaking change: Replaces WallType/StructurallyInsulatedPanel with WallType/StructuralInsulatedPanel.
  • Breaking change: Replaces StandbyLoss with StandbyLoss[Units="F/hr"]/Value for an indirect water heater.
  • Breaking change: Replaces BranchPipingLoopLength with BranchPipingLength for a hot water recirculation system.
  • Breaking change: Replaces Floor/extension/OtherSpaceAboveOrBelow with Floor/FloorOrCeiling.
  • Breaking change: For PTAC with heating, replaces HeatingSystem of type PackagedTerminalAirConditionerHeating with CoolingSystem/IntegratedHeating* elements.
• Breaking change: Now performs full HPXML XSD schema validation (previously just limited checks); yields runtime speed improvements.
• Adds ENERGY STAR ERI calculation for SF National v3.2 and MF National v1.2.
• Adds IECC ERI pathway calculation (2015, 2018, 2021).
• Adds Zero Energy Ready Homes calculation for v1.
• Allows SEER2/HSPF2 efficiency types for central air conditioners and heat pumps.
• Allows calculating all programs (e.g., ERI, ENERGY STAR, IECC, etc.) simultaneously while avoiding duplicate EnergyPlus simulations.
  • Breaking change: Deprecates energy_star.rb script; energy_rating_index.rb will now run all programs specified in the HPXML.
  • Breaking change: The organization of ENERGY STAR output files have changed.
• Allows modeling CFIS ventilation systems with a supplemental fan.
  • Breaking change: New CFISControls/AdditionalRuntimeOperatingMode input required for CFIS ventilation systems.
• Breaking change: The ClimateZoneIECC/Year is now more strict:
  • All runs must include a 2006 IECC climate zone.
  • IECC ERI pathway runs must include an IECC climate zone of the same year.
  • ENERGY STAR ERI runs for SF National v3.2 and MF National v1.2 must include a 2021 IECC climate zone.
  • Zero Energy Ready Homes v1 runs must include a 2015 IECC climate zone.
• Allows modeling room air conditioners with heating or reverse cycle.
• Allows shared dishwasher/clothes washer to be attached to a hot water distribution system instead of a single water heater.
• Adds HVAC capacities, design loads, and design temperatures to csv output files.
• Annual/timeseries outputs:
  • Adds annual emission outputs disaggregated by end use; timeseries emission outputs disaggregated by end use can be requested.
  • Allows generating timeseries unmet hours for heating and cooling.
  • Adds heating/cooling setpoints to timeseries outputs when requesting zone temperatures.
• Improves Kiva foundation model heat transfer by providing better initial temperature assumptions based on foundation type and insulation levels.

Bugfixes

• Fixes units for Peak Loads (kBtu/hr, not kBtu) in ERI____Home.csv output files.
• Bugfix for increasing HVAC capacities due to installation grading.
• Fixes possible output error for ground source heat pumps with a shared hydronic circulation loop.
• Fixes zero energy use for a ventilation fan w/ non-zero fan power and zero airflow rate.

OpenStudio-ERI v1.4.4

OpenStudio-ERI version 1.4.4 has been released. The OpenStudio-ERI workflow calculates an Energy Rating Index (ERI) using the Department of Energy's OpenStudio/EnergyPlus building simulation platform. The open-source workflow is intended to be used by residential software tools that provide a HPXML building description file.

Two packages are available, a minimal zip with a handful of weather files and a full zip with all US TMY3 weather files. OpenStudio-ERI v1.4.4 uses OpenStudio v3.4.0, EnergyPlus v22.1.0, and a proposed HPXML v4.0. Please visit the OpenStudio-ERI v1.4.4 documentation for instructions on how to get started, how to connect software tools to the workflow, etc.

Bugfixes

• Fixes possible simulation error if a slab has an ExposedPerimeter near zero.