Fix GHP experimental model rated conditions by yzhou601 · Pull Request #2204 · NatLabRockies/OpenStudio-HPXML

yzhou601 · 2026-04-30T18:15:44Z

Pull Request Description

GHP experimental models now directly use user-provided COP/EER in E+ coil objects, however, E+ coil rated conditions are different from GLHP rated conditions. We should convert user-provided GLHP COP/EER/capacities before adding coil inputs.

Checklist

Not all may apply:

Schematron validator (EPvalidator.sch) has been updated
Sample files have been added/updated (openstudio tasks.rb update_hpxmls)
Tests have been added/updated (e.g., HPXMLtoOpenStudio/tests/test*.rb and/or workflow/tests/test*.rb)
Documentation has been updated
Changelog has been updated
openstudio tasks.rb update_measures has been run
No unexpected changes to simulation results of sample files

…o GHP_experimental_rated_conditions

…m/NREL/OpenStudio-HPXML into GHP_experimental_rated_conditions

…o GHP_experimental_rated_conditions

…m/NREL/OpenStudio-HPXML into GHP_experimental_rated_conditions

…o GHP_experimental_rated_conditions

…m/NREL/OpenStudio-HPXML into GHP_experimental_rated_conditions

…e unit tests to make sure two models are consistent in rated inputs

yzhou601 · 2026-05-23T00:56:18Z

          # E+ Capacity and EIR as function of temperature curves(bi-quadratic) generated using E+ HVACCurveFitTool
          # See: https://bigladdersoftware.com/epx/docs/24-2/auxiliary-programs/hvac-performance-curve-fit-tool.html#hvac-performance-curve-fit-tool
-          # Catalog data from : https://files.climatemaster.com/Genesis-GS-Series-Product-Catalog.pdf, p180
+          # Catalog data from : https://www.climatemaster.com/download/18.274be999165850ccd5b5b73/1535543867815/lc377-climatemaster-commercial-tranquility-20-single-stage-ts-series-water-source-heat-pump-submittal-set.pdf


Update outdated product links

yzhou601 · 2026-05-23T00:57:53Z

-  GroundSourceCoolRatedWET = 85.0 # degF, Rated water entering temperature for ground-source systems, cooling
  GroundSourceCoolRatedIDB = 80.0 # degF, Rated indoor drybulb for ground-source systems, cooling
  GroundSourceCoolRatedIWB = 67.0 # degF, Rated indoor wetbulb for ground-source systems, cooling
+  GroundSourceHeatGLHPRatedEWT = 32.0 # degF, Rated water entering temperature for ground-source systems, heating


These variables are used to convert E+ rated conditions to GLHP rated conditions

yzhou601 · 2026-05-23T01:00:33Z

        )
        speed = OpenStudio::Model::CoilCoolingWaterToAirHeatPumpVariableSpeedEquationFitSpeedData.new(model, cap_ft_curve, cap_faf_curve, cap_fwf_curve, eir_ft_curve, eir_faf_curve, eir_fwf_curve, waste_heat_ft)
+        # convert GLHP rated COPs/capacities to E+ rated
+		rated_capacity_eplus = UnitConversions.convert(heat_pump.cooling_capacity, 'Btu/hr', 'W') / get_experimental_ghp_rated_condition_conversion(:clg, hp_ap.cool_cap_ft_spec[i]) * hp_ap.cool_capacity_ratios[i]


Convert HPXML rated inputs (GLHP rated conditions) to E+ rated inputs

yzhou601 · 2026-05-23T01:13:20Z

+	    # Need to adjust the capacity to GLHP rated conditions
+        total_cap_curve_value_design = MathTools.biquadratic(UnitConversions.convert(mj.cool_indoor_wetbulb, 'F', 'C'), UnitConversions.convert(entering_temp, 'F', 'C'), clg_ap.cool_cap_ft_spec[hvac_cooling_speed])
+        total_cap_curve_value_glhp_rated = MathTools.biquadratic(UnitConversions.convert(HVAC::GroundSourceCoolRatedIWB, 'F', 'C'), UnitConversions.convert(HVAC::GroundSourceCoolGLHPRatedEWT, 'F', 'C'), clg_ap.cool_cap_ft_spec[hvac_cooling_speed])
+		total_cap_curve_value = total_cap_curve_value_design / total_cap_curve_value_glhp_rated


Uses E+ performance curves to convert design condition to GLHP rated conditions (not E+ rated condition, so here we need to do curve calculation twice).

This will make the heat pumps sized at GLHP rated conditions, consistent with what user provides. Then the capacities will be converted to E+ rated inputs later when we creates E+ models.

yzhou601 · 2026-05-23T01:15:48Z

+    cool_eir_ft_spec = [1.1828664909, -0.0450835550, 0.0009273315, 0.0056194113, 0.0006683467, -0.0007256237]
+	cool_capacity_curve_value = MathTools.biquadratic(UnitConversions.convert(HVAC::GroundSourceCoolRatedIWB, 'F', 'C'), UnitConversions.convert(HVAC::GroundSourceCoolGLHPRatedEWT, 'F', 'C'), cool_cap_ft_spec)
+	cool_eir_curve_value = MathTools.biquadratic(UnitConversions.convert(HVAC::GroundSourceCoolRatedIWB, 'F', 'C'), UnitConversions.convert(HVAC::GroundSourceCoolGLHPRatedEWT, 'F', 'C'), cool_eir_ft_spec)
+	expected_clg_capacity = standard_clg_capacity / cool_capacity_curve_value


Unit test to make sure the rated conditions are converted correctly.
The experimental model should have the consistent rated inputs as standard models before conversion.

Copilot

Pull request overview

This PR updates the ground-to-air heat pump experimental (GHP) implementation so that user-provided GLHP-rated COP/EER/capacities are converted to EnergyPlus coil rated-condition inputs, and updates autosizing/test baselines accordingly.

Changes:

Converts experimental GHP rated COP/capacity inputs from GLHP rated conditions to EnergyPlus rated conditions when populating E+ coil speed data.
Adjusts GHP experimental autosizing so capacities are sized back to GLHP-rated conditions (consistent with HPXML inputs) while using E+ curve forms.
Updates unit tests, changelog, and expected workflow baseline CSV outputs for the new rated-condition behavior.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
`HPXMLtoOpenStudio/resources/hvac.rb`	Adds GLHP-rated EWT constants and converts experimental coil rated COP/capacity inputs to E+ rated conditions.
`HPXMLtoOpenStudio/resources/hvac_sizing.rb`	Adjusts experimental GSHP sizing curve application to account for GLHP vs E+ rated-condition differences.
`HPXMLtoOpenStudio/tests/test_hvac.rb`	Updates GSHP tests to validate the new rated-condition conversion behavior.
`HPXMLtoOpenStudio/resources/defaults.rb`	Updates documentation links/wording for GSHP curve source comments.
`workflow/tests/base_results/results_sizing.csv`	Updates expected sizing results for GSHP experimental cases.
`workflow/tests/base_results/results_simulations_misc.csv`	Updates expected simulation summary outputs for GSHP experimental cases.
`workflow/tests/base_results/results_simulations_loads.csv`	Updates expected load outputs for GSHP experimental cases.
`workflow/tests/base_results/results_simulations_energy.csv`	Updates expected energy outputs for GSHP experimental cases.
`workflow/tests/base_results/results_simulations_bills.csv`	Updates expected bill outputs for GSHP experimental cases.
`Changelog.md`	Adds a bugfix entry for GSHP experimental rated-condition inputs.

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yzhou601 · 2026-05-28T19:22:55Z

+        # convert GLHP rated COPs/capacities to E+ rated
+		rated_capacity_eplus = UnitConversions.convert(heat_pump.cooling_capacity, 'Btu/hr', 'W') / get_experimental_ghp_rated_condition_conversion(:clg, hp_ap.cool_cap_ft_spec[i]) * hp_ap.cool_capacity_ratios[i]
+		rated_cop_eplus = hp_ap.cool_rated_cops[i] * get_experimental_ghp_rated_condition_conversion(:clg, hp_ap.cool_eir_ft_spec[i])
        # TODO: Add net to gross conversion after RESNET PR: https://github.com/NatLabRockies/OpenStudio-HPXML/pull/1879
-        speed.setReferenceUnitGrossRatedTotalCoolingCapacity(UnitConversions.convert(heat_pump.cooling_capacity, 'Btu/hr', 'W') * hp_ap.cool_capacity_ratios[i])
+        speed.setReferenceUnitGrossRatedTotalCoolingCapacity(rated_capacity_eplus)


This hurts my brain to think about this AI's question. I think using airflow rates and water flow rates that are based on GLHP capacities is reasonable here, we don't want those curves to adjust capacities/COPs because the coil is not running at WLHP conditions, right? @jmaguire1 any thoughts?

+        # convert GLHP rated COPs/capacities to E+ rated
        speed = OpenStudio::Model::CoilHeatingWaterToAirHeatPumpVariableSpeedEquationFitSpeedData.new(model, cap_ft_curve, cap_faf_curve, cap_fwf_curve, eir_ft_curve, eir_faf_curve, eir_fwf_curve, waste_heat_ft)
+		rated_capacity_eplus = UnitConversions.convert(heat_pump.heating_capacity, 'Btu/hr', 'W') / get_experimental_ghp_rated_condition_conversion(:htg, hp_ap.heat_cap_ft_spec[i]) * hp_ap.heat_capacity_ratios[i]
+		rated_cop_eplus = hp_ap.heat_rated_cops[i] * get_experimental_ghp_rated_condition_conversion(:htg, hp_ap.heat_eir_ft_spec[i])
        # TODO: Add net to gross conversion after RESNET PR: https://github.com/NatLabRockies/OpenStudio-HPXML/pull/1879
-        speed.setReferenceUnitGrossRatedHeatingCapacity(UnitConversions.convert(heat_pump.heating_capacity, 'Btu/hr', 'W') * hp_ap.heat_capacity_ratios[i])
-        speed.setReferenceUnitGrossRatedHeatingCOP(hp_ap.heat_rated_cops[i])
+        speed.setReferenceUnitGrossRatedHeatingCapacity(rated_capacity_eplus)
+        speed.setReferenceUnitGrossRatedHeatingCOP(rated_cop_eplus)
        speed.setReferenceUnitRatedAirFlow(UnitConversions.convert(UnitConversions.convert(heat_pump.heating_capacity, 'Btu/hr', 'ton') * hp_ap.heat_capacity_ratios[i] * hp_ap.heat_rated_cfm_per_ton, 'cfm', 'm^3/s'))


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…m/NREL/OpenStudio-HPXML into GHP_experimental_rated_conditions

…o GHP_experimental_rated_conditions

… can directly apply at interim speeds

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Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 10 comments.

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…m/NREL/OpenStudio-HPXML into GHP_experimental_rated_conditions

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Pull request overview

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yzhou601 added 2 commits April 30, 2026 11:41

convert user provided cops

55ae9a1

hvac sizing

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github-project-automation Bot added this to OpenStudio-HPXML Apr 30, 2026

github-project-automation Bot moved this to Triage in OpenStudio-HPXML Apr 30, 2026

yzhou601 self-assigned this Apr 30, 2026

yzhou601 added 2 commits April 30, 2026 12:48

capacity, refactor

ae7df53

one more cleanup

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shorowit added this to the 1.13.0 milestone May 5, 2026

yzhou601 and others added 7 commits May 11, 2026 14:33

temporarily disabled experimental unit tests

dff73ee

Merge branch 'master' of https://github.com/NREL/OpenStudio-HPXML int…

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…o GHP_experimental_rated_conditions

changed capacity ratios and cop ratios based on rated data

76c1ee7

Latest results. [skip ci]

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update comments

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Merge branch 'GHP_experimental_rated_conditions' of https://github.co…

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…m/NREL/OpenStudio-HPXML into GHP_experimental_rated_conditions

Merge branch 'master' of https://github.com/NREL/OpenStudio-HPXML int…

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…o GHP_experimental_rated_conditions

shorowit moved this from Triage to In progress in OpenStudio-HPXML May 12, 2026

GitHub Action and others added 9 commits May 12, 2026 17:21

Latest results. [skip ci]

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Merge branch 'master' of https://github.com/NREL/OpenStudio-HPXML int…

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…o GHP_experimental_rated_conditions

Merge branch 'GHP_experimental_rated_conditions' of https://github.co…

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…m/NREL/OpenStudio-HPXML into GHP_experimental_rated_conditions

Latest results. [skip ci]

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Merge branch 'master' of https://github.com/NREL/OpenStudio-HPXML int…

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…o GHP_experimental_rated_conditions

Merge branch 'GHP_experimental_rated_conditions' of https://github.co…

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…m/NREL/OpenStudio-HPXML into GHP_experimental_rated_conditions

update unit tests

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revert experimental assumptions to stick to E+ rated conditions, wrot…

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…e unit tests to make sure two models are consistent in rated inputs

changelog

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yzhou601 commented May 23, 2026

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yzhou601 marked this pull request as ready for review May 23, 2026 01:16

Latest results. [skip ci]

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typo fix in the unit test

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Merge branch 'master' of https://github.com/NREL/OpenStudio-HPXML int…

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…o GHP_experimental_rated_conditions

fix index, the capacity ratios are calculated at E+ rated conditions,…

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… can directly apply at interim speeds

exclude a warning

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remove duplicate method explanation

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yzhou601 commented Apr 30, 2026 •

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