Effect of Temperature on Long-Term Thermal Conductivity of Closed-Cell Insulation Materials
Bibliographic record
Abstract
This study examines the isolated impact of temperature on the accelerated aging of closed-cell foam insulation materials. Laboratory aging of closed-cell foams was conducted at three temperatures: −10, 23 and 50 °C. This was to cover the range of the material’s in-service range within a Canadian climate. Three polyisocyanurate foam and one extruded polystyrene foam insulations were considered in the study. The three polyisocyanurate foam products tested showed significant variability in polynomial functions at lower mean temperatures when newly manufactured; however, these differences were found to diminish over time. Thermal conductivity decreased between 0% and 17% depending on mean temperature following equivalent 5-year aging at 23 °C. Aging polyisocyanurate specimens at −10 °C was found to decrease rate of change in thermal conductivity by approximately 5% compared to aging at 23 °C when measured at a mean temperature of 24 °C, while aging at 50 °C had a smaller impact. However, at mean temperatures below the beginning of condensation point, there was greater variability in the impact of aging temperature. For the extruded polystyrene, thermal conductivity decreased between 8% and 10% following equivalent 5-year aging at 23 °C and displayed a linear relationship with a 23% difference in thermal conductivity between −10 °C and 40 °C.
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How this classification was reachedexpand
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 | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".