Releases: NREL/OpenStudio-HPXML
OpenStudio-HPXML v1.9.1
OpenStudio-HPXML v1.9.1 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
OpenStudio-HPXML v1.9.1 uses OpenStudio v3.9.0, EnergyPlus v24.2.0, and HPXML v4.1-rc1. Please visit the OpenStudio-HPXML v1.9.1 documentation for instructions on how to get started, how to generate an appropriate HPXML file, etc. The full set of US TMY3 weather files can be obtained from here.
New Features
- Now can be used to obtain ACCA Manual J approval; see the OpenStudio-HPXML documentation.
Bugfixes
- Fixes Manual J design load calculations for radiant floors.
OpenStudio-HPXML v1.9.0
OpenStudio-HPXML version 1.9.0 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
OpenStudio-HPXML v1.9.0 uses OpenStudio v3.9.0, EnergyPlus v24.2.0, and HPXML v4.1-rc1. Please visit the OpenStudio-HPXML v1.9.0 documentation for instructions on how to get started, how to generate an appropriate HPXML file, 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.
- Allows
Site/Address/ZipCode
to be provided instead ofClimateandRiskZones/WeatherStation/extension/EPWFilePath
, in which case the closest TMY3 weather station will be automatically selected. - Allows optional inputs for modeling skylight curbs and/or shafts.
- Allows modeling exterior horizontal insulation for a slab-on-grade foundation (or basement/crawlspace floor).
- Allows alternative infiltration input
AirInfiltrationMeasurement/LeakinessDescription
, in which the infiltration level is estimated using age of home, climate zone, foundation type, etc. - Window shading enhancements:
- Allows optional
InteriorShading/Type
input (blinds, shades, curtains) as a way to default summer/winter shading coefficients. - Allows optional
ExteriorShading/Type
input (trees, solar screens/films, etc.) as a way to default summer/winter shading coefficients. - Allows optional
InsectScreen
input.
- Allows optional
- Adds optional
BuildingConstruction/UnitHeightAboveGrade
input for, e.g., apartment units of upper levels where the wind speed, and thus infiltration rate, is higher. - Updates operational calculations (i.e., when
NumberofResidents
provided):- Updates hot water usage based on FSEC study.
- Updates misc/tv plug load usage based on RECS 2020 data.
- Updates relationship between number of bedrooms and number of occupants to use RECS 2020 instead of RECS 2015.
- Allows optional
HeatingCapacity
andBackupHeatingCapacity
inputs for heat pump water heaters (HPWHs). - Central Fan Integrated Supply (CFIS) mechanical ventilation enhancements:
- Allows CFIS systems without automatic flow control of outdoor air (
CFISControls/HasOutdoorAirControl=false
). - Allows CFIS systems with no strategy to meet remainder of ventilation target (
CFISControls/AdditionalRuntimeOperatingMode="none"
). - Allows CFIS systems with supplemental fans that run simultaneously with the air handler (
CFISControls/extension/SupplementalFanRunsWithAirHandlerFan=true
). - Allows CFIS systems with timer control, in which ventilation operation occurs at a fixed interval (
CFISControls/extension/ControlType="timer"
). - Allows CFIS systems to be attached to ductless HVAC systems like PTHPs (requires using a DSE=1 distribution system, see documentation).
- Allows CFIS systems without automatic flow control of outdoor air (
- HVAC Manual J design load and sizing calculations:
- Adds optional
DistributionSystemType/AirDistribution/extension/ManualJInputs/BlowerFanHeatBtuh
input for HVAC equipment whose performance data has not been adjusted for blower heat. - Adds optional
DistributionSystemType/AirDistribution/extension/ManualJInputs/DefaultTableDuctLoad
input to use Manual J default duct factor tables instead of ASHRAE 152. - Adds optional
DistributionSystemType/HydronicDistribution/extension/ManualJInputs/HotWaterPipingBtuh
input to include hydronic distribution piping losses through unconditioned spaces. - Adds optional
HVACSizingControl/ManualJInputs/InfiltrationShieldingClass
input to specify wind shielding class for infiltration design load calculations. - Adds optional
HVACSizingControl/ManualJInputs/InfiltrationMethod
input to specify which method to use for infiltration design load calculations. - Updates heat pump HERS sizing methodology to better prevent unmet hours in warmer climates.
- Misc Manual J design load calculation improvements.
- Breaking change: Disaggregates "Walls" into "Above Grade Walls" and "Below Grade Walls" in results_design_load_details.csv output file.
- Significant speed improvements when using optional space-level design load calculations.
- Adds optional
- Advanced research features:
- Optional input
SimulationControl/AdvancedResearchFeatures/OnOffThermostatDeadbandTemperature
to model on/off thermostat deadband with start-up degradation for single and two speed AC/ASHP systems and time-based realistic staging for two speed AC/ASHP systems. - Optional input
SimulationControl/AdvancedResearchFeatures/HeatPumpBackupCapacityIncrement
to model multi-stage electric backup coils with time-based staging. - Maximum power ratio detailed schedule for variable-speed HVAC systems can now be used with
NumberofUnits
dwelling unit multiplier.
- Optional input
- BuildResidentialHPXML measure:
- Breaking change: Replaced
slab_under_width
andslab_perimeter_depth
arguments withslab_under_insulation_width
andslab_perimeter_insulation_depth
- Breaking change: Replaced
schedules_vacancy_periods
,schedules_power_outage_periods
, andschedules_power_outage_periods_window_natvent_availability
arguments withschedules_unavailable_period_types
,schedules_unavailable_period_dates
, andschedules_unavailable_period_window_natvent_availabilities
; this improves flexibility for handling more unavailable period types.
- Breaking change: Replaced
- Utility bill calculations:
- Allows OpenEI URDB tariffs that have $/day fixed charges.
- Updates
openei_rates.zip
with the latest residential utility rates from the OpenEI U.S. Utility Rate database.
- Adds a warning if the sum of supply/return duct leakage to outside values is very high.
Bugfixes
- Prevents possible error if only one of FracSensible/FracLatent are provided for a PlugLoad or FuelLoad; Breaking change: FracSensible and FracLatent must now be both be provided or omitted.
- Prevents possible error when using multiple
Attic
/Foundation
elements for the same attic/foundation type. - Adds error-checking for
NumberofConditionedFloorsAboveGrade
=0, which is not allowed per the documentation. - Fixes utility bill calculations if there is battery storage or a generator.
- BuildResidentialScheduleFile measure: Fixes possible divide by zero error during generation of stochastic clothes washer and dishwasher schedules.
- Allows negative values for
Building/Site/Elevation
. - Fixes lower element height for a water heater using the advanced
WaterHeatingSystem/extension/TankModelType=stratified
. - Fixes possible error for a combi boiler system.
- Fixes error if modeling a ground-to-air heat pump with a separate backup heating system.
- Fixes default CFIS fan power during ventilation only mode.
- Fixes a bug that potentially oversizes heat pumps when detailed performance capacity fractions are provided.
- For a CFIS system with a supplemental fan, fixes supplemental fan runtime when using sub-hourly timesteps.
- Fixes GSHP rated fan/pump powers in net to gross calculations and improves default modeled pump power (W/ton).
OpenStudio-HPXML v1.8.1
OpenStudio-HPXML version 1.8.1 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
OpenStudio-HPXML v1.8.1 uses OpenStudio v3.8.0, EnergyPlus v24.1.0, and HPXML v4.0-rc4. Please visit the OpenStudio-HPXML v1.8.1 documentation for instructions on how to get started, how to generate an appropriate HPXML file, etc. The full set of US TMY3 weather files can be obtained from here.
Bugfixes
- Fixes cfm/ton restriction from incorrectly applying to furnace heating airflow rate.
OpenStudio-HPXML v1.8.0
OpenStudio-HPXML version 1.8.0 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
OpenStudio-HPXML v1.8.0 uses OpenStudio v3.8.0, EnergyPlus v24.1.0, and HPXML v4.0-rc4. Please visit the OpenStudio-HPXML v1.8.0 documentation for instructions on how to get started, how to generate an appropriate HPXML file, 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 v4.0-rc4.
- Adds BPI-2400 HPXML test files and results; see Testing Framework for more information.
- Updates per ANSI/RESNET/ICC 301-2022 w/ Addendum C:
- Breaking change: For shared water heaters,
NumberofUnitsServed
is replaced byextension/NumberofBedroomsServed
. - Breaking change: For shared hot water recirculation systems,
NumberofUnitsServed
is replaced byNumberofBedroomsServed
. - Allows shared batteries (batteries serving multiple dwelling units).
- Updated default CFIS fan power to 0.58 W/cfm.
- Removed natural ventilation availability RH constraint; HR constraint remains.
- Refrigerator and freezer schedules may now be based on ambient temperature using new
TemperatureScheduleCoefficients
andConstantScheduleCoefficients
inputs; the refrigerator default schedule uses these new inputs. - Default schedules updated for cooking ranges, lighting, plug loads, televisions, hot water recirculation pumps, and occupant heat gains.
- Adds schedule inputs for hot water recirculation pumps and general water use internal gains.
- Updated water heater installation default location.
- Updated calculation of hot water piping length for buildings with both conditioned and unconditioned basements to avoid double counting.
- Updated how imbalanced infiltration and mechanical ventilation are combined on an hourly basis.
- Updated handling of duct leakage imbalance induced infiltration.
- Small change to default flow rate for imbalanced mechanical ventilation systems.
- Updated window default interior shade coefficients to be calculated based on SHGC.
AverageCeilingHeight
now used in natural ACH/CFM infiltration calculations.
- Breaking change: For shared water heaters,
- Breaking change: Replaces
BuildingSummary/Site/extension/GroundConductivity
withBuildingSummary/Site/Soil/Conductivity
. - Breaking change: Modeling whole SFA/MF buildings is now specified using a
SoftwareInfo/extension/WholeSFAorMFBuildingSimulation=true
element instead ofbuilding-id=ALL
argument. - Breaking change: Skylights attached to roofs of attics (e.g., with shafts or sun tunnels) must include the
Skylight/AttachedToFloor
element. - Air source heat pump/air conditioner enhancements:
- Adds heat pump backup autosizing methodology input (
HeatPumpBackupSizingMethodology
) with choices of "emergency" and "supplemental". - Allows autosizing with detailed performance data inputs for variable-speed HVAC systems using
CapacityFractionOfNominal
. - Now defaults to -20F for
CompressorLockoutTemperature
for variable-speed heat pump systems.
- Adds heat pump backup autosizing methodology input (
- Ground source heat pump enhancements:
- Allows optional detailed inputs related to geothermal loop (
HVACPlant/GeothermalLoop
). - Allows optional ground diffusivity input.
- Updates to using G-Functions from the G-Function Library for Modeling Vertical Bore Ground Heat Exchanger.
- Updated heating/cooling performance curves to reflect newer equipment.
- Adds geothermal loop outputs (number/length of boreholes) to annual results output file.
- Allows optional detailed inputs related to geothermal loop (
- HVAC Manual J design load and sizing calculations:
- Breaking change: Outputs for "Infiltration/Ventilation" category disaggregated into "Infiltration" and "Ventilation".
- Breaking change: Outputs for "Windows" category no longer includes AED excursion; now a separate "AED Excursion" category.
- Allows optional
HeatingAutosizingFactor
,CoolingAutosizingFactor
,BackupHeatingAutosizingFactor
inputs to scale HVAC capacities for autosized equipment. - Allows optional
HeatingAutosizingLimit
,CoolingAutosizingLimit
,BackupHeatingAutosizingLimit
inputs to set maximum HVAC capacities ceiling for autosized equipment. - Allows optional zone-level and space-level design load calculations using HPXML
Zones/Zone[ZoneType="conditioned"]/Spaces/Space
elements. - Allows additional outdoor design condition inputs:
DailyTemperatureRange
andHumidityDifference
. - Adds a new detailed output file with block/space load details by surface, AED curves, etc.
- Miscellaneous improvements.
- Allows optional
Ducts/DuctShape
andDucts/DuctFractionRectangular
inputs, which affect duct effective R-value used for modeling. - Adds optional
Slab/extension/GapInsulationRValue
input for cases where a slab has horizontal (under slab) insulation. - Allows radiant barriers for additional locations (attic gable walls and floor); reduced emissivity due to dust assumed for radiant barriers on attic floor.
- Adds window and skylight
GlassType
options of "low-e, high-solar-gain" and "low-e, low-solar-gain"; updates U-factor/SHGC lookup tables. - Updates default temperature capacitance multiplier from 1 to 7, an average value found in the literature when calibrating timeseries EnergyPlus indoor temperatures to field data.
- Allows optional building site inputs (
GeoLocation/Latitude
,GeoLocation/Longitude
,Elevation
); useful when located far from, or at a very different elevation than, the EPW weather station. - Updates default
ShieldingofHome
to be "well-shielded" for single-family attached and multifamily dwelling units. - Improves heating/cooling component loads; for timesteps where there is no heating/cooling load, assigns heat transfer to heating or cooling by comparing indoor temperature to the average of heating/cooling setpoints.
- Adds net energy and net electricity timeseries output columns even when there is no PV or generator.
- Allow alternative label energy use (W) input for ceiling fans.
- Replaced state-average default fuel prices with EIA State Energy Data System (SEDS) prices.
- Adds more error-checking for inappropriate inputs (e.g., HVAC SHR=0 or clothes washer IMEF=0).
- Updates to run_simulation.rb script:
- Allows requesting timeseries outputs with different frequencies (e.g.,
--hourly enduses --monthly temperatures
). - Breaking change: Deprecates
--add-timeseries-output-variable
; EnergyPlus output variables can now be requested like other timeseries categories (using e.g.--hourly 'Zone People Occupant Count'
). - Adds an optional
--skip-simulation
argument that allows skipping the EnergyPlus simulation.
- Allows requesting timeseries outputs with different frequencies (e.g.,
- BuildResidentialHPXML measure:
- Breaking change: Replaces
roof_radiant_barrier
/roof_radiant_barrier_grade
arguments withradiant_barrier_attic_location
/radiant_barrier_grade
. - Allows specifying number of bedrooms served by the water heater which is used for apportioning tank losses; Breaking change: Replaces
water_heater_num_units_served
withwater_heater_num_bedrooms_served
. - Allows defining multiple unavailable periods; Breaking change: arguments renamed to
schedules_vacancy_periods
,schedules_power_outage_periods
, andschedules_power_outage_periods_window_natvent_availability
. - Adds detailed performance data inputs for variable-speed air source HVAC systems.
- Adds heat pump backup sizing methodology input.
- Add soil and moisture type arguments (for determining ground conductivity and diffusivity) and optional geothermal loop arguments for ground source heat pumps.
- The "Geometry: Building Number of Units" input is now written to the HPXML
NumberofUnitsInBuilding
element. - Adds a blower fan efficiency input for specifying fan power W/cfm at maximum speed.
- Breaking change: Replaces
- BuildResidentialScheduleFile measure:
- Allows appending columns to an existing CSV file rather than overwriting.
- Other plug load schedules now use Other schedule fractions per ANSI/RESNET/ICC 301-2022 Addendum C.
- TV plug load schedules now use TV schedule fractions from the American Time Use Survey and monthly multipliers from the 2010 Building America Analysis Spreadsheets.
- Ceiling fan schedules now use ceiling fan schedule fractions and monthly multipliers from ANSI/RESNET/ICC 301-2022 Addendum C.
- ReportUtilityBills measure:
- Adds new optional arguments for registering (with the OpenStudio runner) annual or monthly utility bills.
- Advanced research features:
- Breaking change: Replaces
SimulationControl/TemperatureCapacitanceMultiplier
withSimulationControl/AdvancedResearchFeatures/TemperatureCapacitanceMultiplier
. - Allows an optional boolean input
SimulationControl/AdvancedResearchFeatures/DefrostModelType
for heat pump advanced defrost model. - Adds maximum power ratio detailed schedule for variable-speed HVAC systems to model shedding controls per AHRI 1380.
- Breaking change: Replaces
Bugfixes
- Fixes error if using AllowIncreasedFixedCapacities=true w/ HP detailed performance data.
- Prevents mains water temperature from going below freezing (0 C).
- Fixes error if HPXML has emissions scenario and abbreviated run period.
- Fixes detailed schedule error-checking where schedules with MAX < 1 were incorrectly allowed.
- Fixes error if using MF space types (e.g., "other heated space") and the building has no HVAC equipment...
OpenStudio-HPXML v1.7.0
OpenStudio-HPXML version 1.7.0 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
OpenStudio-HPXML v1.7.0 uses OpenStudio v3.7.0, EnergyPlus v23.2.0, and HPXML v4.0-rc2. Please visit the OpenStudio-HPXML v1.7.0 documentation for instructions on how to get started, how to generate an appropriate HPXML file, 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
HotTubs/HotTub
withSpas/PermanentSpa
. - Replaces
PortableHeater
andFixedHeater
withSpaceHeater
.
- Allows simulating whole multifamily (MF) buildings in a single combined simulation:
- Breaking change: Multiple elements move from
SoftwareInfo/extension
toBuildingDetails/BuildingSummary/extension
to allow variation across units:HVACSizingControl
ShadingControl
SchedulesFilePath
NaturalVentilationAvailabilityDaysperWeek
- Allows
NumberofUnits
to be used as a multiplier on dwelling unit simulation results to reduce simulation runtime. - See the OpenStudio-HPXML documentation for more detail.
- Breaking change: Multiple elements move from
- HVAC modeling 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.
- Allows detailed heating and cooling performance data (min/max COPs and capacities at different outdoor temperatures) for variable-speed systems.
- 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: "Hot Tub" outputs renamed to "Permanent Spa".
- Adds "Peak Electricity: Annual Total (W)" output.
- Adds battery resilience hours output; allows requesting timeseries output.
- ReportUtilityBills measure: Allows reporting monthly utility bills in addition to (or instead of) annual bills.
- BuildResidentialHPXML measure:
- Allow duct area fractions (as an alternative to duct areas in ft^2).
- Allow duct locations to be provided while defaulting duct areas (i.e., without providing duct area/fraction inputs).
- Add generic "attic" and "crawlspace" location choices for supply/return ducts, water heater, and battery.
- Always validate the HPXML file before applying defaults and only optionally validate the final HPXML file.
- Adds manufactured home belly as a foundation type and allows modeling ducts in a manufactured home belly.
- Battery losses now split between charging and discharging.
- Interior/exterior window shading multipliers are now modeled using the EnergyPlus incident solar multiplier.
- Allows
WaterFixture/FlowRate
as an alternative toLowFlow
; hot water credit is now calculated based on fraction of low flow fixtures. - Allows above-grade basements/crawlspaces defined solely with Wall (not FoundationWall) elements.
- Updates to 2022 EIA energy costs.
- Added README.md documentation for all OpenStudio measures.
Bugfixes
- Fixes battery resilience output to properly incorporate battery losses.
- Fixes lighting multipliers not being applied when kWh/yr inputs are used.
- Fixes running detailed schedules with mixed timesteps (e.g., hourly heating/cooling setpoints and 15-minutely miscellaneous plug load schedules).
- Fixes calculation of utility bill fixed costs for simulations with abbreviated run periods.
- Fixes error if heat pump
CompressorLockoutTemperature
==BackupHeatingLockoutTemperature
. - Fixes possible "Electricity category end uses do not sum to total" error for a heat pump w/o backup.
- Fixes ground source heat pump fan/pump adjustment to rated efficiency.
- Fixes error if conditioned basement has
InsulationSpansEntireSlab=true
. - Fixes ReportSimulationOutput outputs for the Parametric Analysis Tool (PAT).
- Fixes missing radiation exchange between window and sky when an interior/exterior window shading multiplier less than 1 exists.
- Fixes monthly shallow ground temperatures (used primarily in HVAC autosizing) for the southern hemisphere.
- Various HVAC sizing bugfixes and improvements.
- Fixes low-speed heating COPs for some two-speed ASHPs and cooling COPs for some single-speed ACs/HPs.
- BuildResidentialHPXML measure: Fixes air distribution CFA served when there is not a central system that meets 100% of the load.
OpenStudio-HPXML v1.6.0
OpenStudio-HPXML version 1.6.0 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
OpenStudio-HPXML v1.6.0 uses OpenStudio v3.6.1, EnergyPlus v23.1.0, and a proposed HPXML v4.0. Please visit the OpenStudio-HPXML v1.6.0 documentation for instructions on how to get started, how to generate an appropriate HPXML file, 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.
- Updates to newer proposed HPXML v4.0:
- Breaking change: Replaces
VentilationFan/Quantity
andCeilingFan/Quantity
withCount
. - Breaking change: Replaces
PVSystem/InverterEfficiency
withPVSystem/AttachedToInverter
andInverter/InverterEfficiency
. - Breaking change: Replaces
WaterHeatingSystem/extension/OperatingMode
withWaterHeatingSystem/HPWHOperatingMode
for heat pump water heaters.
- Breaking change: Replaces
- Output updates:
- Breaking change: Adds
End Use: Heating Heat Pump Backup Fans/Pumps
(disaggregated fromEnd Use: Heating Fans/Pumps
). - Breaking change: Replaces
Component Load: Windows
withComponent Load: Windows Conduction
andComponent Load: Windows Solar
. - Breaking change: Replaces
Component Load: Skylights
withComponent Load: Skylights Conduction
andComponent Load: Skylights Solar
. - Breaking change: Adds
Component Load: Lighting
(disaggregated fromComponent 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.
- Allows specifying the number of decimal places for timeseries output.
- Msgpack outputs are no longer rounded (since there is no file size penalty to storing full precision).
- Annual emissions and utility bills now include all fuel/end uses, even if zero.
- ReportSimulationOutput measure: Allows disabling individual annual output sections.
- Breaking change: Adds
- Breaking change: Deprecates
OccupancyCalculationType
("asset" or "operational").- If
NumberofResidents
not provided, an asset calculation is performed assuming standard occupancy per ANSI/RESNET/ICC 301. - If
NumberofResidents
is provided, an operational calculation is performed using a relationship between #Bedrooms and #Occupants from RECS 2015.
- If
- Heat pump enhancements:
- Allows
HeatingCapacityRetention[Fraction | Temperature]
inputs to define cold-climate performance; likeHeatingCapacity17F
but can apply to autosized systems and can use a user-specified temperature. - Default mini-split heating capacity retention updated from 0.4 to 0.5 (at 5 deg-F).
- Allows
CompressorLockoutTemperature
as an optional input to control the minimum temperature the compressor can operate at. - 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. - Provides a warning if
BackupHeatingSwitchoverTemperature
orBackupHeatingLockoutTemperature
are low and may cause unmet hours. - Autosizing is no longer all-or-none; backup heating can be autosized (defaulted) while specifying the heat pump capacities, or vice versa.
- Allows
extension/CrankcaseHeaterPowerWatts
as an optional input; defaults to 50 W for central HPs/ACs and mini-splits. - Increased consistency between variable-speed central HP and mini-split HP models for degradation coefficients, gross SHR calculations, etc.
- Allows
- Infiltration changes:
- Breaking change: Infiltration for SFA/MF dwelling units must include
TypeOfInfiltrationLeakage
("unit total" or "unit exterior only"). - Breaking change: Replaces
BuildingConstruction/extension/HasFlueOrChimney
withAirInfiltration/extension/HasFlueOrChimneyInConditionedSpace
; defaults now incorporate HVAC/water heater location. - Allows infiltration to be specified using
CFMnatural
orEffectiveLeakageArea
.
- Breaking change: Infiltration for SFA/MF dwelling units must include
- Lighting changes:
- LightingGroups can now be specified using kWh/year annual consumption values as an alternative to fractions of different lighting types.
- LightingGroups for interior, exterior, and garage are no longer required; if not provided, these lighting uses will not be modeled.
- HVAC sizing enhancements:
- Allows optional inputs under
HVACSizingControl/ManualJInputs
to override Manual J defaults for HVAC autosizing calculations. - Updates to better align various default values and algorithms with Manual J.
- Updates design load calculations to handle conditioned basements with insulated slabs.
- Allows optional inputs under
- Duct enhancements:
- Allows modeling ducts buried in attic loose-fill insulation using
Ducts/DuctBuriedInsulationLevel
. - Allows specifying
Ducts/DuctEffectiveRValue
, the value that will be used in the model, though its use is not recommended.
- Allows modeling ducts buried in attic loose-fill insulation using
- Allows modeling a pilot light for non-electric heating systems (furnaces, stoves, boilers, and fireplaces).
- Allows summer vs winter shading seasons to be specified for windows and skylights.
- Allows defining one or more
UnavailablePeriods
(e.g., occupant vacancies or power outage periods). - Stochastic schedules for garage lighting and TV plug loads now use interior lighting and miscellaneous plug load schedules, respectively.
- Performance improvement for HPXML files w/ large numbers of
Building
elements. - Weather cache files (*foo-cache.csv) are no longer used/needed.
Bugfixes
- Fixes
BackupHeatingSwitchoverTemperature
for a heat pump w/ separate backup system; now correctly ceases backup operation above this temperature. - Fixes error if calculating utility bills for an all-electric home with a detailed JSON utility rate.
- Stochastic schedules now excludes columns for end uses that are not stochastically generated.
- Fixes operational calculation when the number of residents is set to zero.
- Fixes possible utility bill calculation error for a home with PV using a detailed electric utility rate.
- Fixes defaulted mechanical ventilation flow rate for SFA/MF buildings, with respect to infiltration credit.
- HPXML files w/ multiple
Building
elements now only show warnings for the singleBuilding
being simulated. - Adds a warning for SFA/MF dwelling units without at least one attached wall/ceiling/floor surface.
- Various fixes for window/skylight/duct design loads for Manual J HVAC autosizing calculations.
- Ensure that ductless HVAC systems do not have a non-zero airflow defect ratio specified.
- Fixes possible "A neighbor building has an azimuth (XX) not equal to the azimuth of any wall" for SFA/MF units with neighboring buildings for shade.
- Fixes reported loads when no/partial HVAC system (e.g., room air conditioner that meets 30% of the cooling load).
OpenStudio-HPXML v1.5.1
OpenStudio-HPXML version 1.5.1 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
OpenStudio-HPXML v1.5.1 uses OpenStudio v3.5.0, EnergyPlus v22.2.0, and a proposed HPXML v4.0. Please visit the OpenStudio-HPXML v1.5.1 documentation for instructions on how to get started, how to generate an appropriate HPXML file, etc. The full set of US TMY3 weather files can be obtained from here.
New Features
- When
Battery/Location
not provided, now defaults to garage if present, otherwise outside. - BuildResidentialScheduleFile measure:
- Allows requesting a subset of end uses (columns) to be generated.
Bugfixes
- Fixes total/net electricity timeseries outputs to include battery charging/discharging energy.
- Fixes error when a non-electric water heater has jacket insulation and the UEF metric is used.
OpenStudio-HPXML v1.5.0
OpenStudio-HPXML version 1.5.0 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
OpenStudio-HPXML v1.5.0 uses OpenStudio v3.5.0, EnergyPlus v22.2.0, and a proposed HPXML v4.0. Please visit the OpenStudio-HPXML v1.5.0 documentation for instructions on how to get started, how to generate an appropriate HPXML file, 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
withFloors/Floor
. - Breaking change:
Floor/FloorType
(WoodFrame, StructuralInsulatedPanel, SteelFrame, or SolidConcrete) is a required input. - Breaking Change: All
Ducts
must now have aSystemIdentifier
. - Breaking Change: Replaces
WallType/StructurallyInsulatedPanel
withWallType/StructuralInsulatedPanel
. - Breaking change: Replaces
SoftwareInfo/extension/SimulationControl/DaylightSaving/Enabled
withBuilding/Site/TimeZone/DSTObserved
. - Breaking Change: Replaces
StandbyLoss
withStandbyLoss[Units="F/hr"]/Value
for an indirect water heater. - Breaking Change: Replaces
BranchPipingLoopLength
withBranchPipingLength
for a hot water recirculation system. - Breaking Change: Replaces
Floor/extension/OtherSpaceAboveOrBelow
withFloor/FloorOrCeiling
. - Breaking change: For PTAC with heating, replaces
HeatingSystem
of type PackagedTerminalAirConditionerHeating withCoolingSystem/IntegratedHeating*
elements.
- Breaking Change: Replaces
- Breaking Change: Now performs full HPXML XSD schema validation (previously just limited checks); yields runtime speed improvements.
- Breaking Change: HVAC/DHW equipment efficiencies can no longer be defaulted (e.g., based on age of equipment); they are now required.
- Breaking Change: Deprecates ReportHPXMLOutput measure; HVAC autosized capacities & design loads moved to
results_annual.csv
. - Breaking change: BuildResidentialHPXML measure: Replaces arguments using 'auto' for defaults with optional arguments of the appropriate data type.
- Utility bill calculations:
- Breaking change: Removes utility rate and PV related arguments from the ReportUtilityBills measure in lieu of HPXML file inputs.
- Allows calculating one or more utility bill scenarios (e.g., net metering vs feed-in tariff compensation types for a simulation with PV).
- Adds detailed calculations for tiered, time-of-use, or real-time pricing electric rates using OpenEI tariff files.
- Lithium ion battery:
- Allows detailed charging/discharging schedules via CSV files.
- Allows setting round trip efficiency.
- Breaking change: Lifetime model is temporarily disabled;
Battery/extension/LifetimeModel
is not allowed.
- Allows SEER2/HSPF2 efficiency types for central air conditioners and heat pumps.
- Allows setting the natural ventilation availability (days/week that operable windows can be opened); default changed from 7 to 3 (M/W/F).
- Allows specifying duct surface area multipliers.
- Allows modeling CFIS ventilation systems with supplemental fans.
- Allows shared dishwasher/clothes washer to be attached to a hot water distribution system instead of a single water heater.
- Allows heating/cooling seasons that don't span the entire year.
- Allows modeling room air conditioners with heating or reverse cycle.
- Allows setting the ground soil conductivity used for foundation heat transfer and ground source heat pumps.
- Allows setting the EnergyPlus temperature capacitance multiplier.
- EnergyPlus modeling changes:
- Switches Kiva foundation model timestep from 'Hourly' to 'Timestep'; small increase in runtime for sub-hourly simulations.
- Improves Kiva foundation model heat transfer by providing better initial temperature assumptions based on foundation type and insulation levels.
- Annual/timeseries outputs:
- Allows timeseries timestamps to be start or end of timestep convention; Breaking change: now defaults to start of timestep.
- 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.
- Allows CSV timeseries output to be formatted for use with the DView application.
- Adds heating/cooling setpoints to timeseries outputs when requesting zone temperatures.
- Disaggregates Battery outputs from PV outputs.
- Design temperatures, used to calculate design loads for HVAC equipment autosizing, are now output in
in.xml
andresults_annual.csv
.
Bugfixes
- Fixes possible incorrect autosizing of heat pump separate backup systems with respect to duct loads.
- Fixes incorrect autosizing of heat pump integrated backup systems if using MaxLoad/HERS sizing methodology and cooling design load exceeds heating design load.
- Fixes heating (or cooling) setpoints affecting the conditioned space temperature outside the heating (or cooling) season.
- Fixes handling non-integer number of occupants when using the stochastic occupancy schedule generator.
- Fixes units for Peak Loads (kBtu/hr, not kBtu) in annual results file.
- Fixes possible output error for ground source heat pumps with a shared hydronic circulation loop.
- Provides an error message if the EnergyPlus simulation used infinite energy.
- Fixes zero energy use for a ventilation fan w/ non-zero fan power and zero airflow rate.
- Fixes excessive heat transfer when foundation wall interior insulation does not start from the top of the wall.
- Fixes how relative paths are treated when using an OpenStudio Workflow.
- Fixes possible simulation error if a slab has an ExposedPerimeter near zero.
- Fixes possible "Could not identify surface type for surface" error.
- Fixes possible ruby error when defaulting water heater location.
- Battery round trip efficiency now correctly affects results.
- BuildResidentialHPXML measure:
- Fixes aspect ratio convention for single-family attached and multifamily dwelling units.
OpenStudio-HPXML v1.4.0
OpenStudio-HPXML version 1.4.0 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
Two packages are available, a minimal zip with a handful of weather files and a full zip with all US TMY3 weather files. OpenStudio-HPXML v1.4.0 uses OpenStudio v3.4.0, EnergyPlus v22.1.0, and a proposed HPXML v4.0. Please visit the OpenStudio-HPXML v1.4.0 documentation for instructions on how to get started, how to generate an appropriate HPXML file, etc.
New Features
- Updates to OpenStudio 3.4.0/EnergyPlus 22.1.
- High-level optional
OccupancyCalculationType
input to specify operational vs asset calculation. Defaults to asset. If operational,NumberofResidents
is required. - Allows calculating one or more emissions scenarios (e.g., high renewable penetration vs business as usual) for different emissions types (e.g., CO2e).
- New ReportUtilityBills reporting measure: adds a new results_bills.csv output file to summarize calculated utility bills.
- Switches from EnergyPlus SQL output to MessagePack output for faster performance and reduced file sizes when requesting timeseries outputs.
- New heat pump capabilities:
- Breaking change: Replaces the
UseMaxLoadForHeatPumps
sizing option withHeatPumpSizingMethodology
, which has three choices:ACCA
: nominal capacity sized per ACCA Manual J/S based on cooling design loads, with some oversizing allowances for larger heating design loads.HERS
(default): nominal capacity sized equal to the larger of heating/cooling design loads.MaxLoad
: nominal capacity sized based on the larger of heating/cooling design loads, while taking into account the heat pump's capacity retention at the design temperature.
- Allows the separate backup system to be a central system (e.g., central furnace w/ ducts). Previously only non-central system types were allowed.
- Heat pumps with switchover temperatures are now autosized by taking into account the switchover temperature, if higher than the heating design temperature.
- Allows
BackupHeatingLockoutTemperature
as an optional input to control integrated backup heating availability during, e.g., a thermostat heating setback recovery event; defaults to 40F.
- Breaking change: Replaces the
- New water heating capabilities:
- Allows conventional storage tank water heaters to use a stratified (rather than mixed) tank model via
extension/TankModelType
; higher precision but runtime penalty. Defaults to mixed. - Allows operating mode (standard vs heat pump only) for heat pump water heaters (HPWHs) via
extension/OperatingMode
. Defaults to standard. - Updates combi boiler model to be simpler, faster, and more robust by using separate space/water heating plant loops and boilers.
- Allows conventional storage tank water heaters to use a stratified (rather than mixed) tank model via
- New capabilities for hourly/sub-hourly scheduling via schedule CSV files:
- Detailed HVAC and water heater setpoints.
- Detailed heat pump water heater operating modes.
- EnergyPlus modeling changes:
- Switches from ScriptF to CarrollMRT radiant exchange algorithm.
- Updates HVAC fans to use fan power law (cubic relationship between fan speed and power).
- Updates HVAC rated fan power assumption per ASHRAE 1449-RP.
- Allows specifying a
StormWindow
element for windows/skylights; U-factors and SHGCs are automatically adjusted. - Allows an optional
AirInfiltrationMeasurement/InfiltrationHeight
input. - Allows an optional
Battery/UsableCapacity
input; now defaults to 0.9 x NominalCapacity (previously 0.8). - For CFIS systems, allows an optional
extension/VentilationOnlyModeAirflowFraction
input to address duct losses during ventilation only mode. - Breaking change: Each
VentilationFan
must have one (and only one)UsedFor...
element set to true. - BuildResidentialHPXML measure:
- Breaking change: Changes the zip code argument name to
site_zip_code
. - Adds optional arguments for schedule CSV files, HPWH operating mode, water heater tank model, storm windows, heat pump lockout temperature, battery usable capacity, and emissions scenarios.
- Adds support for ambient foundations for single-family attached and apartment units.
- Adds support for unconditioned attics for apartment units.
- Adds an optional argument to store additional custom properties in the HPXML file.
- Adds an optional argument for whether the HPXML file is written with default values applied; defaults to false.
- Adds an optional argument for whether the HPXML file is validated; defaults to false.
- Breaking change: Changes the zip code argument name to
- ReportSimulationOutput measure:
- Breaking change: New "End Use: <Fuel>: Heating Heat Pump Backup" output, disaggregated from "End Use: <Fuel>: Heating".
- Adds "Energy Use: Total" and "Energy Use: Net" columns to the annual results output file; allows timeseries outputs.
- Adds a "Fuel Use: Electricity: Net" timeseries output column for homes with electricity generation.
- Adds optional argument for requesting timeseries EnergyPlus output variables.
- Adds ability to include
TimeDST
and/orTimeUTC
timestamp column(s) in results_timeseries.csv. - Timestamps in results_timeseries.csv are output in ISO 8601 standard format.
- Allows user-specified annual/timeseries output file names.
- ReportHPXMLOutput measure:
- Adds "Enclosure: Floor Area Foundation" output row in results_hpxml.csv.
- Adds support for shared hot water recirculation systems controlled by temperature.
- Relaxes requirement for
ConditionedFloorAreaServed
for air distribution systems; now only needed if duct surface areas not provided. - Allows MessagePack annual/timeseries output files to be generated instead of CSV/JSON.
Bugfixes
- Adds more stringent limits for
AirflowDefectRatio
andChargeDefectRatio
(now allows values from 1/10th to 10x the design value). - Catches case where leap year is specified but weather file does not contain 8784 hours.
- Fixes possible HVAC sizing error if design temperature difference (TD) is negative.
- Fixes an error if there is a pool or hot tub, but the pump
Type
is set to "none". - Adds more decimal places in output files as needed for simulations with shorter timesteps and/or abbreviated run periods.
- Timeseries output fixes: some outputs off by 1 hour; possible negative combi boiler values.
- Fixes range hood ventilation interaction with infiltration to take into account the location of the cooking range.
- Fixes possible EMS error for ventilation systems with low (but non-zero) flow rates.
- Fixes documentation for
Overhangs/Depth
inputs; units should be ft and not inches. - The
WaterFixturesUsageMultiplier
input now also applies to general water use internal gains and recirculation pump energy (for some control types). - BuildResidentialHPXML measure:
- Fixes units for "Cooling System: Cooling Capacity" argument (Btu/hr, not tons).
- Fixes incorrect outside boundary condition for shared gable walls of cathedral ceilings, now set to adiabatic.
OpenStudio-HPXML v1.3.0
OpenStudio-HPXML version 1.3.0 has been released. The OpenStudio-HPXML workflow uses HPXML building description files to run residential simulations on the Department of Energy's OpenStudio/EnergyPlus building simulation platform.
Two packages are available, a minimal zip with a handful of weather files and full zip with all US TMY3 weather files. OpenStudio-HPXML v1.3.0 uses OpenStudio v3.3.0, EnergyPlus v9.6.0, and a proposed HPXML v4.0. Please visit the OpenStudio-HPXML v1.3.0 documentation for instructions on how to get started, how to generate an appropriate HPXML file, etc.
New Features
- Updates to OpenStudio 3.3.0/EnergyPlus 9.6.0.
- Breaking change: Replaces "Unmet Load" outputs with "Unmet Hours".
- Breaking change: Renames "Load: Heating" and "Peak Load: Heating" (and Cooling) outputs to include "Delivered".
- Breaking change: Any heat pump backup heating requires
HeatPump/BackupType
("integrated" or "separate") to be specified. - Breaking change: For homes with multiple PV arrays, all inverter efficiencies must have the same value.
- Breaking change: HPXML schema version must now be '4.0' (proposed).
- Moves
ClothesDryer/extension/IsVented
toClothesDryer/Vented
. - Moves
ClothesDryer/extension/VentedFlowRate
toClothesDryer/VentedFlowRate
. - Moves
FoundationWall/Insulation/Layer/extension/DistanceToTopOfInsulation
toFoundationWall/Insulation/Layer/DistanceToTopOfInsulation
. - Moves
FoundationWall/Insulation/Layer/extension/DistanceToBottomOfInsulation
toFoundationWall/Insulation/Layer/DistanceToBottomOfInsulation
. - Moves
Slab/PerimeterInsulationDepth
toSlab/PerimeterInsulation/Layer/InsulationDepth
. - Moves
Slab/UnderSlabInsulationWidth
toSlab/UnderSlabInsulation/Layer/InsulationWidth
. - Moves
Slab/UnderSlabInsulationSpansEntireSlab
toSlab/UnderSlabInsulation/Layer/InsulationSpansEntireSlab
.
- Moves
- Initial release of BuildResidentialHPXML measure, which generates an HPXML file from a set of building description inputs.
- Expanded capabilities for scheduling:
- Allows modeling detailed occupancy via a schedule CSV file.
- Introduces a measure for automatically generating detailed smooth/stochastic schedule CSV files.
- Expands simplified weekday/weekend/monthly schedule inputs to additional building features.
- Allows
HeatingSeason
&CoolingSeason
to be specified for defining heating and cooling equipment availability.
- Adds a new results_hpxml.csv output file to summarize HPXML values (e.g., surface areas, HVAC capacities).
- Allows modeling lithium ion batteries.
- Allows use of
HeatPump/BackupSystem
for modeling a standalone (i.e., not integrated) backup heating system. - Allows conditioned crawlspaces to be specified; modeled as crawlspaces that are actively maintained at setpoint.
- Allows non-zero refrigerant charge defect ratios for ground source heat pumps.
- Expands choices allowed for
Siding
(Wall/RimJoist) andRoofType
(Roof) elements. - Allows "none" for wall/rim joist siding.
- Allows interior finish inputs (e.g., 0.5" drywall) for walls, ceilings, and roofs.
- Allows specifying the foundation wall type (e.g., solid concrete, concrete block, wood, etc.).
- Allows additional fuel types for generators.
- Switches to the EnergyPlus Fan:SystemModel object for all HVAC systems.
- Introduces a small amount of infiltration for unvented spaces.
- Updates the assumption of flue losses vs tank losses for higher efficiency non-electric storage water heaters.
- Revises shared mechanical ventilation preconditioning control logic to operate less often.
- Adds alternative inputs:
- Window/skylight physical properties (
GlassLayers
,FrameType
, etc.) instead ofUFactor
&SHGC
. Ducts/FractionDuctArea
instead ofDucts/DuctSurfaceArea
.Length
instead ofArea
for foundation walls.Orientation
instead ofAzimuth
for all applicable surfaces, PV systems, and solar thermal systems.- CEER (Combined Energy Efficiency Ratio) instead of EER for room ACs.
UsageBin
instead ofFirstHourRating
(for water heaters w/ UEF metric).CFM50
instead ofCFM25
orPercent
for duct leakage.
- Window/skylight physical properties (
- Allows more defaulting (optional inputs):
- Mechanical ventilation airflow rate per ASHRAE 62.2-2019.
- HVAC/DHW system efficiency (by age).
- Mechanical ventilation fan power (by type).
- Color (solar absorptance) for walls, roofs, and rim joists.
- Foundation wall distance to top/bottom of insulation.
- Door azimuth.
- Radiant barrier grade.
- Whole house fan airflow rate and fan power.
- Adds more warnings of inputs based on ANSI/BPI 2400 Standard.
- Removes error-check for number of bedrooms based on conditioned floor area, per RESNET guidance.
- Updates the reporting measure to register all outputs from the annual CSV with the OS runner (for use in, e.g., PAT).
- Removes timeseries CSV output columns that are all zeroes to reduce file size and processing time.
- Improves consistency of installation quality calculations for two/variable-speed air source heat pumps and ground source heat pumps.
- Relaxes requirement for heating (or cooling) setpoints so that they are only needed if heating (or cooling) equipment is present.
- Adds an
--ep-input-format
argument to run_simulation.rb to choose epJSON as the EnergyPlus input file format instead of IDF. - Eliminates EnergyPlus warnings related to unused objects or invalid output meters/variables.
- Allows modeling PTAC and PTHP HVAC systems.
- Allows user inputs for partition wall mass and furniture mass.
Bugfixes
- Improves ground reflectance when there is shading of windows/skylights.
- Improves HVAC fan power for central forced air systems.
- Fixes mechanical ventilation compartmentalization area calculation for SFA/MF homes with surfaces with InteriorAdjacentTo==ExteriorAdjacentTo.
- Negative
DistanceToTopOfInsulation
values are now disallowed. - Fixes workflow errors if a
VentilationFan
has zero airflow rate or zero hours of operation. - Fixes duct design load calculations for HPXML files with multiple ducted HVAC systems.
- Fixes ground source heat pump rated airflow.
- Relaxes
Overhangs
DistanceToBottomOfWindow vs DistanceToBottomOfWindow validation when Depth is zero. - Fixes possibility of double-counting HVAC distribution losses if an
HVACDistribution
element has both AirDistribution properties and DSE values - Fixes possibility of incorrect "Peak Electricity: Winter Total (W)" and "Peak Electricity: Summer Total (W)" outputs for homes with duct losses.
- Fixes heating/cooling seasons (used for e.g. summer vs winter window shading) for the southern hemisphere.
- Fixes possibility of EnergyPlus simulation failure for homes with ground-source heat pumps and airflow and/or charge defects.
- Fixes peak load/electricity outputs for homes with ground-source heat pumps and airflow and/or charge defects.