ZEMCH 2019 International Conference Proceedings April.2020 | Page 169
3.2. TSV
During the measurement period, 217 TSV data were collected. Figure 4 shows the percentage of
TSV responses. The most common answer was 1 (slightly warm), accounting for 28.57%, and 25.35%
felt that it was neutral. Responses showing colder thermal sensation (‐1 (slightly cool), ‐2 (cool), ‐3 (cold))
accounted for only 18.90%, while those showing warmer thermal sensation (1 (slightly warm), 2 (warm),
3 (hot)) accounted for more than half. As such, a large number of responders answered that the indoor
thermal environment was warm.
Figure 4. Percentage of TSV
Figure 5. PMV and TSV Distribution
Figure 5 shows the distribution of PMV and TSV. According to the figure, the distribution of TSV
forms at a higher position than that of PMV. The average of PMV was ‐0.25, and the average of TSV
was 0.61, with the TSV average forming at about 0.86 higher. This indicates that the occupants felt
warmer thermal sensation than PMV. The following section will associate the difference between PMV
and TSV with carbon dioxide concentration for analysis.
3.3.Dv
Figure 6 is the Dv distribution for each carbon dioxide concentration. The average was ‐0.86, and
the standard deviation was 1.25. About 80% of the total data showed negative Dv, and 96% of the results
showed a negative result when the carbon dioxide concentration was over 2,000 ppm. This implies that
many occupants felt warmer thermal sensation than PMV, which was aggravated when the carbon
dioxide level was over 2,000 ppm.
Figure 7 displays the average Dv for each carbon dioxide concentration segment. The higher the
carbon dioxide concentration segment, the lower the Dv. Dv average at carbon dioxide concentration
lower than 2,500 ppm was ‐0.55, while that at carbon dioxide concentration over 2,500 ppm was ‐1.42,
which was almost three times lower. This means that the thermal sensation was warmer by a scale of
over 1, indicating that occupants may feel warmer at segments with higher carbon dioxide
concentration. From these results, we can see that carbon dioxide concentration affects TSV, and it
would be necessary to assess thermal comfort levels considering the carbon dioxide levels for more
accurate thermal comfort control.
TSV Analysis on Changes in the Carbon Dioxide Concentration in a University Library Reading Room
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