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.