Novel Reduced GWP Refrigerant Compositions for Stationary Air Conditioning
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
The current fluids most widely used for small and mid-sized air conditioning systems globally are R-410A and R-22. While these fluids have many positive attributes for cooling, they are the subject of valid criticisms regarding their high direct global warming potential (GWP) and, in the case of R-22, ozone depletion potential (ODP) also. In the interest of improved environmental sustainability, a new class of refrigerant molecule has been developed, the hydrofluoroolefin, or HFO. While the very low direct GWP values of these molecules are attractive, none of the HFOs by themselves are fully satisfactory for use in conventional stationary AC system designs, for reasons of concern about low capacity and flammability. Blended refrigerant candidates have been developed to provide better overall safety and performance, while retaining significant environmental sustainability properties versus the legacy refrigerants. There is as yet no universal agreement on what are the most critical properties for air conditioning fluids. No single candidate has yet been developed that meets every proposed requirement for a refrigerant fluid. This paper discusses three candidate fluids that have been developed to meet three of the most often cited sets of environmental, physical and performance properties for air conditioning. Each of these candidate fluids possesses desirable, but different sets of properties. The trade-offs and relative performance and environmental merits of each will be discussed. The three fluids vary in direct GWP values, flammability, capacity, and critical temperature. One is a 2L flammable gas that gives capacity performance near that of R-410A. One is a nonflammable composition for use to replace R-22 in high ambient temperature environments. The third is a 2L flammable replacement for R-22 with a direct GWP of less than 150. In designing and evaluating these new compositions, the trade-offs that exist between refrigeration capacity, efficiency (COP), temperature glide, GWP value, and flammability have been explored and assessed. We report on the comparisons of these compositions in AC measurement and modeling work. The new compositions have been evaluated with thermodynamic refrigeration cycle models at standard AC conditions, and at high ambient temperature operating conditions, and show good performance. Testing is underway to evaluate performance of these new compositions in laboratory equipment and in actual operating systems, as compared to R-22 performance in the same or similar systems. The status of the testing and some results generated to date will be reported in this paper. These new compositions should provide useful options to help maintain the quality of life and health benefits that accrue from air conditioning and refrigeration, but in an energy efficient and environmentally sustainable manner.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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