Heat Pump Sub-Zero HSPF2 & Ambient COP Degradation Benchmark Matrix
Source-informed COP decay modeling (+47°F down to -25°F), compressor capacity retention, and electric auxiliary strip staging kinetics referencing AHRI 210/240 and DOE Appendix M1 test protocols.
1. Abstract & Dataset Scope
Provides a source-informed deterministic benchmark matrix modeling heating Coefficient of Performance (COP), delivered thermal capacity retention percentage, compressor electrical power demand, and auxiliary resistive element staging kinetics across 30 outdoor temperature points (-25°F to +47°F) under AHRI 210/240-2023 and DOE 10 CFR Part 430 Appendix M1 calculation protocols. Contrasts standard variable-speed inverters against cold-climate enhanced vapor injection (ccASHP with EVI) architectures.
2. Technical Methodology & Benchmark Formulation
Model formulation derived from published PNNL cold-climate heat pump monitoring studies, NEEP ccASHP specification frameworks, and AHRI 210/240-2023 rating conditions across standard temperature test bins (+47°F, +35°F with defrost penalty derating, +17°F, +5°F, down to -25°F). Thermodynamic heating capacity decay and COP curves are modeled deterministically using vapor injection compressor modulation equations and DOE 10 CFR Part 430 Appendix M1 seasonal derate assumptions. Values represent standardized benchmark scenarios rather than certified test results for any individual commercial heat pump model.
3. Data Dictionary & Variable Definitions
| Variable Name | Symbol | Unit | Type | Description | Example |
|---|---|---|---|---|---|
| Outdoor Ambient Temperature (°F) | T_amb_f | °F | Float | Dry-bulb outdoor ambient test temperature in Fahrenheit | 5 |
| Outdoor Ambient Temperature (°C) | T_amb_c | °C | Float | Dry-bulb outdoor ambient test temperature in Celsius | -15 |
| Compressor Technology | Tech | Architecture Category | String | Inverter refrigeration platform (Cold-Climate EVI vs Standard Single-Stage) | Cold-Climate EVI (Flash Injection) |
| Nominal Rating Capacity | Cap_nom | BTU/hr | Integer | Rated sensible plus latent heating capacity at 47°F outdoor rating point | 36000 |
| Actual Heating Capacity | Cap_act | BTU/hr | Integer | Delivered heating output at specified outdoor temperature | 27360 |
| Capacity Retention Ratio | Cap_ratio | Ratio (Cap/Cap47) | Float | Available sensible heating output relative to nominal 47°F rating | 0.76 |
| Compressor COP | COP_comp | Dimensionless | Float | Thermodynamic compressor heating coefficient of performance before defrost | 2.15 |
| Defrost Penalty Factor | K_defrost | Multiplier | Float | Derating factor accounting for periodic reverse-cycle frost melt defrost cycles | 1 |
| Effective COP | COP_eff | Dimensionless | Float | Net heating Coefficient of Performance delivered to conditioned space | 2.15 |
| Compressor Electrical Power | P_comp | kW | Float | Steady-state electrical power draw of inverter compressor and outdoor fan | 3.45 |
| Auxiliary Resistance Heat | P_aux | kW | Float | Engaged electric resistance auxiliary strip element wattage | 0 |
| Total Electrical Demand | P_total | kW | Float | Combined instantaneous electrical demand (compressor + auxiliary strips) | 3.45 |
| Hourly Operating Cost | Cost_hr | $/Hour | Float | Estimated hourly running cost at U.S. national residential average rate baseline | 0.63 |
| System Operational Status | Status | Classification | String | Operating regime classification (Optimal Operation, Frost / Defrost Active, EVI Boost Mode, Sub-Zero Operation, Auxiliary Staged) | EVI Boost Mode |
4. Sample Data Records Preview
Displaying 6 representative rows (Full dataset contains 30 Records)| temp f | temp c | arch | cop | cap ret pct | power kw | aux kw | hourly cost |
|---|---|---|---|---|---|---|---|
| 47 | 8.3 | Cold-Climate EVI | 4.1 | 100 | 2.57 | 0 | $0.47 |
| 35 | 1.7 | Cold-Climate EVI (Defrost Active) | 3.35 | 94 | 2.75 | 0 | $0.50 |
| 17 | -8.3 | Cold-Climate EVI | 2.65 | 84 | 3.1 | 0 | $0.57 |
| 5 | -15 | Cold-Climate EVI | 2.15 | 76 | 3.45 | 0 | $0.63 |
| -5 | -20.5 | Cold-Climate EVI | 1.85 | 68 | 3.6 | 0 | $0.66 |
| -15 | -26.1 | Cold-Climate EVI + Aux Heat | 1.5 | 55 | 3.6 | 5 | $1.58 |
| 17 | -8.3 | Standard Inverter | 2.2 | 65 | 2.89 | 0 | $0.53 |
| 5 | -15 | Standard Inverter + Aux Heat | 1.65 | 48 | 2.85 | 5 | $1.44 |
| -5 | -20.5 | Standard Inverter + Aux Heat | 1.25 | 32 | 2.5 | 10 | $2.29 |
5. Limitations & Engineering Disclaimer
This dataset provides modeled engineering benchmarks and reference calculations. It is not certified laboratory test data, does not replace manufacturer performance specifications, does not constitute code-compliance certification or installation approval, and should not be used as a substitute for applicable mechanical/electrical codes, AHJ requirements, manufacturer engineering instructions, or qualified professional HVAC/engineering review.
6. Dataset Citation (BibTeX / APA / IEEE)
When referencing this dataset in academic preprints, technical reports, or computational tooling, please cite using the formal reference metadata below:
APA Style
IEEE Style
BibTeX Record
@dataset{powerlab_2026_heatpump_subzero_dataset,
author = {Miad S. and {PowerLab Clean Energy Engineering Group}},
title = {Heat Pump Sub-Zero HSPF2 & Ambient COP Degradation Benchmark Matrix},
year = {2026},
publisher = {Figshare},
version = {1.0.0},
doi = {10.6084/m9.figshare.34018341},
url = {https://www.powelab.org/datasets/heat-pump-sub-zero-cop-degradation-benchmark}
}