Latest Options for Replacing HFC-134a Refrigerant in MACs
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
<div class="section abstract"><div class="htmlview paragraph">With the passage of the Kigali Amendment to the Montreal Protocol, HFC-134a refrigerant will be phased down in all markets worldwide, including those where automotive companies have been slow to embrace HFO-1234yf. Engineers are currently being challenged to design MAC systems using alternate low GWP refrigerants that are allowed by regulations, and are simultaneously cost-effective to manufacture, energy efficient, safe, reliable, affordable for consumers, and also suitable in electrified vehicles. This paper documents the latest international research and developments on: 1) refrigerants that satisfy the Montreal Protocol and national environmental regulations; 2) secondary loop MAC (SL-MACs) that achieve lower refrigerant emissions and higher energy efficiency in cooling-only and cooling and heating (heat pump) applications; 3) progress in Europe, North America, and Asia on heat pump systems for electric and hybrid vehicles optimized for safety and energy efficiency, and 4) the latest SAE standards for the emerging use of HFC-152a in SL-MACs. The authors of this paper are an interdisciplinary team from organizations based in China, Germany, India, Italy, and the United States, including experts from vehicle manufacturing, AC component and system suppliers, and non-government environmental organizations.</div></div>
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it