Field comparison study of indoor environment quality in office buildings with underfloor and overhead ventilation systems
Bibliographic record
Abstract
The use of UFAD (Underfloor Air Distribution) systems is increasing rapidly and reported advantages of UFAD include energy savings and improved indoor air quality. At present few publications documenting measurements of ventilation effectiveness and indoor environment quality in occupied buildings with UFAD have been identified. In this field comparison study we measured several aspects of the thermal environment in two buildings with different ventilation systems (underfloor air distribution and mixing) located in Montreal (Quebec). The results are presented in terms of thermal stratification, predicted thermal comfort indices (VATD , limit to air speed and PMV/ PPD), and IAQ index (CO2 level and stratification). The aim of the study was to determine whether UFAD in practice results in improved ventilation effectiveness compared to typical overhead air distribution without affecting the thermal comfort. The study found that there was little stratification for UFAD under operating conditions and it performed as a mixing system, thus no improvement in ventilation effectiveness was identified in the occupied zone, in comparison to the reference mixing system. In addition the predicted thermal comfort in term of VATD, air speed and PMV/PPD was similar to those obtained for mixing ventilation and was within the acceptable limits set by ASHRAE 55-2010.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".