OpenStudio-ERI v1.9.3

OpenStudio-ERI version 1.9.3 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 v1.9.3 uses OpenStudio v3.9.0, EnergyPlus v24.2.0, and HPXML v4.1-rc1. Please visit the OpenStudio-ERI v1.9.3 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 possibility of ERI Rated Home having extra balanced supplemental ventilation due to floating point comparison.

OpenStudio-ERI v1.9.2

OpenStudio-ERI version 1.9.2 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 v1.9.2 uses OpenStudio v3.9.0, EnergyPlus v24.2.0, and HPXML v4.1-rc1. Please visit the OpenStudio-ERI v1.9.2 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

• Updates HERS test outputs to match the latest RESNET accreditation forms.

OpenStudio-ERI v1.9.1

OpenStudio-ERI version 1.9.1 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 v1.9.1 uses OpenStudio v3.9.0, EnergyPlus v24.2.0, and HPXML v4.1-rc1. Please visit the OpenStudio-ERI v1.9.1 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 clothes washer configurations for ZERH v2 and ENERGY STAR SFNH 3.2/MFNC 1.2 programs when the rated home does not include a clothes washer.

OpenStudio-ERI v1.9.0

OpenStudio-ERI version 1.9.0 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 v1.9.0 uses OpenStudio v3.9.0, EnergyPlus v24.2.0, and HPXML v4.1-rc1. Please visit the OpenStudio-ERI v1.9.0 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 3.9/EnergyPlus 24.2/HPXML v4.1-rc1.
• Adds 2024 IECC ERI pathway calculation.
• Breaking change: Renamed Emissions: <EmissionsType>: RESNET: XXX to Emissions: <EmissionsType>: ANSI301: XXX in Annual Home CSV output files.
• Implements ANSI/RESNET/ICC Standard 301-2022 Addendum E for CFIS systems.
  • ERICalculation/Version and CO2IndexCalculation/Version can now be "2022CE".
  • Breaking change: Removes FanPower/FanPowerDefaulted and VentilationOnlyModeAirflowFraction inputs for CFIS systems.
  • Breaking change: Adds CFISControls/HasOutdoorAirControl and CFISControls/extension/ControlType inputs for CFIS systems.
  • Adds choice of "none" for CFISControls/AdditionalRuntimeOperatingMode input for CFIS systems.
  • Adds optional CFISControls/extension/SupplementalFanRunsWithAirHandlerFan input for CFIS systems.
• Adds inputs for modeling skylight curbs and/or shafts.
• Relaxes IECC climate zone requirements.
  • IECC climate zone years other than 2006 are now always optional; for programs that use specific IECC climate zone years (e.g., 2021 for ZERH SF 2.0), that year is used if provided, otherwise the next earliest provided year will be used with the assumption that the climate zone has not changed across the years.
  • See the documentation for more information.
• Updates HERS Diagnostic Output to v0.3.0.

Bugfixes

• Adds error-checking for NumberofConditionedFloorsAboveGrade=0, which is not allowed per the documentation.
• Fixes error if a heating system and a heat pump (that only provides cooling) are attached to the same distribution system.
• Fixes double counting of battery storage losses in ERI calculation; CO2e Index is unaffected.
• Misc Manual J design load calculation improvements.
• Fixes GSHP rated fan/pump powers in net to gross calculations.

OpenStudio-ERI v1.8.0

OpenStudio-ERI version 1.8.0 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 v1.8.0 uses OpenStudio v3.8.0, EnergyPlus v24.1.0, and HPXML v4.0-rc4. Please visit the OpenStudio-ERI v1.8.0 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 3.8, EnergyPlus 24.1, HPXML 4.0-rc4.
• Implements ANSI/RESNET/ICC Standard 301-2022 and Addendum C.
  • Breaking change: For shared water heaters, NumberofUnitsServed is replaced by extension/NumberofBedroomsServed.
  • Breaking change: For shared hot water recirculation systems, NumberofUnitsServed is replaced by NumberofBedroomsServed.
  • ERICalculation/Version and CO2IndexCalculation/Version can now be "2022C" or "2022".
  • Allows modeling electric battery storage, including shared batteries ("2022C" or newer).
  • The ElectricAuxiliaryEnergy input for boilers is no longer used.
• Breaking change: ERI_Results.csv and ERI_Worksheet.csv combined into a single ERI_Results.csv that better reflects the current ERI calculation components; additional fields (e.g., PEfrac) added and a few renamed/removed.
• Breaking change: Skylights attached to roofs of attics (e.g., with shafts or sun tunnels) must include the Skylight/AttachedToFloor element.
• Breaking change: Each VentilationFan must have one (and only one) UsedFor... element set to true.
• HERS software tests:
  • HERS Hot Water test HPXMLs have been updated to be direct EnergyPlus simulations (like the HERS HVAC & DSE tests already were); they are no longer run through ERI simulations.
  • HERS HVAC DSE tests now use duct effective R-values instead of nominal insulation R-values to demonstrate that they pass RESNET acceptance criteria.
• Adds --diagnostic-output commandline argument to produce a diagnostic output file per the HERS Diagnostic Output Schema.
• Allows AverageCeilingHeight to be optionally provided for infiltration calculations.
• Allows Roof/RadiantBarrier to be omitted; defaults to false.
• Allows FractionDuctArea as alternative to DuctSurfaceArea
• Allows alternative LabelEnergyUse (W) input for ceiling fans.
• Allows Slab/extension/GapInsulationRValue input for cases where a slab has horizontal (under slab) insulation.
• Ground source heat pump model enhancements.
• Improves heating/cooling component loads.
• Now defaults to -20F for CompressorLockoutTemperature for variable-speed air-to-air heat pumps.
• Adds more error-checking for inappropriate inputs (e.g., HVAC SHR=0 or clothes washer IMEF=0).
• Clarifies that HVAC Capacity=-1 can be used to autosize HVAC equipment for research purposes or to run tests. It should not be used for a real home, and a warning will be issued when it's used.

Bugfixes

• Fixes incorrect Reference Home mechanical ventilation flowrate for attached units (when Aext is not 1).
• Fixes possible 301ruleset.rb error due to floating point arithmetic.

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.