4 Utilising Passive Design Strategies for Analysing Thermal …
45
Similarly, PPD values were also estimated corresponding to each of the PMV
value obtained for each instant of time. With the minimum PPD value being 5%,
the maximum PPD value reached 36.01%, which is again much beyond the 20%
restriction, as recommended by the standards (ASHRAE 2010; ISO 2005). The PPD
results also suggest that though there have been instances where the PPD values lie
within the 20% range, but there are other cases as well wherein the PPD values have
crossed the 20% cap, suggesting that for the study duration, a maximum of 36.01% of
the occupants are dissatisfied with their thermal environment. Therefore, this value
should also be tried to be brought down in order to reach the ideal conditions.
A graph between the two values has also been plotted, as shown in Fig. 4.3, which
agrees well with the ideal PMV versus PPD curve, that can be obtained from any
literature (ASHRAE 2010; ISO 2005). The graph between the two values obtained
indicates that the minimum PPD value of 5% corresponds to the 0 PMV value,
implying that even at thermally neutral conditions, at least 5% of the occupants
remain dissatisfied, as stated in Sect. 4.1.4. The graph also depicts that moving away
from the 0 PMV value, towards either negative or positive sides of the graph, the
percentage of dissatisfied occupants is increasing, while only a very small percentage
of people are feeling comfortable with their thermal environment, and hence, lie
within the zone of −0.5 to +0.5. It also implies that some percentage of occupants
still feel thermally satisfied with their environment on moving only a little away from
the ideal zone. However, as the threshold crosses 20%, measures need to be taken to
maintain the thermal environment within the ideal range and reduce the percentage
of people dissatisfied with their thermal environment.
Fig. 4.3 Experimental
results
0
3
6
9
12
15
18
21
24
27
30
33
36
39
42
-1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4
PPD (%)
PMV
45
Similarly, PPD values were also estimated corresponding to each of the PMV
value obtained for each instant of time. With the minimum PPD value being 5%,
the maximum PPD value reached 36.01%, which is again much beyond the 20%
restriction, as recommended by the standards (ASHRAE 2010; ISO 2005). The PPD
results also suggest that though there have been instances where the PPD values lie
within the 20% range, but there are other cases as well wherein the PPD values have
crossed the 20% cap, suggesting that for the study duration, a maximum of 36.01% of
the occupants are dissatisfied with their thermal environment. Therefore, this value
should also be tried to be brought down in order to reach the ideal conditions.
A graph between the two values has also been plotted, as shown in Fig. 4.3, which
agrees well with the ideal PMV versus PPD curve, that can be obtained from any
literature (ASHRAE 2010; ISO 2005). The graph between the two values obtained
indicates that the minimum PPD value of 5% corresponds to the 0 PMV value,
implying that even at thermally neutral conditions, at least 5% of the occupants
remain dissatisfied, as stated in Sect. 4.1.4. The graph also depicts that moving away
from the 0 PMV value, towards either negative or positive sides of the graph, the
percentage of dissatisfied occupants is increasing, while only a very small percentage
of people are feeling comfortable with their thermal environment, and hence, lie
within the zone of −0.5 to +0.5. It also implies that some percentage of occupants
still feel thermally satisfied with their environment on moving only a little away from
the ideal zone. However, as the threshold crosses 20%, measures need to be taken to
maintain the thermal environment within the ideal range and reduce the percentage
of people dissatisfied with their thermal environment.
Fig. 4.3 Experimental
results
0
3
6
9
12
15
18
21
24
27
30
33
36
39
42
-1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4
PPD (%)
PMV