A comparative study on the performance of a R22 window air conditioner retrofitted with R407C/R290/R600a refrigerant mixture
Bibliographic record
Abstract
SYNOPSIS HFCs are the leading options for replacing R22 in air conditioning applications due to the Montreal Protocol. Among the HFCs, one of the more promising refrigerants is R407C, a zeotropic refrigerant mixture with a glide temperature difference of roughly 6°C. However, R407C could not be used as a drop-in substitute since HFCs are immiscible with conventional mineral oils and POE is used as a lubricant. But POE is highly hygroscopic in nature and will cause adverse effects in the system. Previous research reported that M20 (80% R407C and 20% HC blend by weight) could be a viable substitute without changing the mineral oil. But, in that study, the condenser tube length was increased by 19% to limit the discharge pressure within the acceptable limits of an existing R22 compressor. In the present study a test is conducted to assess the performance of M20 as a drop-in substitute for R22 in a window air conditioner, without increasing condenser length but with the capillary length alone changed. The indoor and outdoor air temperatures were varied in accordance with BIS 1391 (1992) standard and the test was carried out in a psychrometric test facility. Experimental results showed that M20 refrigerant had 4.18% to 7.47% lower cooling capacity compared to the R22 system. Hence M20 can be used as a drop-in substitute for R22 in a window air-conditioner but with marginal reduction in cooling capacity.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".