52
S. F. Ali and D. Rakshit
Table 4.8 Results of provision of window glazing
Type
Double pane clear
glass
Triple pane clear
glass
Tinted glass Low-e glass
Minimum PMV −0.61
−0.59
−0.81
−0.63
Maximum PMV
0.85
0.82
1.06
0.77
Maximum PPD
20.55
19.25
28.86
17.47
recommended by standards (ASHRAE 2010; ISO 2005) and the curve dominates
towards the zone of positive PMV values, making the environment comparatively
warmer, and resulting in attaining a maximum PPD value because of that. However,
that maximum PPD value is still approximately equal to the upper limit of the required
PPD, even though the PMV value is a little beyond the maximum tolerable PMV
value.
Analogously, the window properties were modified according to the cases undertaken for the study and the simulation was run for each of them. The thermal comfort
indices obtained using the simulation analysis for each of the case were plotted
against each other and it was noticed that the PMV versus PPD curves of the cases
followed the same trend as depicted in Fig. 4.7, though with different PMV as well as
PPD ranges. The results of these cases are tabulated in Table 4.8. Both the PMV and
PPD values in each of the cases were observed to have comparatively shrunk down
and tended towards the ideal range, with a considerable shift from a cooler environment to a warmer one. This suggests that changing the glazing type to the cases
chosen can result in admitting the heat inside and restricting its flow to the ambient.
Moreover, comparison of the results of these cases revealed that the difference in
their magnitudes are due to the different thermal properties they possess, enlisted in
Table 4.7. Comparison of results against each of the cases suggests that the low-e
glass has a better performance since the maximum reduction in values were observed
in this case, while minimum improvement was observed in the case of tinted glass.
4.3.4 Optimal Solution for Maximum Thermal Comfort
Implementing passive design technologies in buildings have a huge impact on the
energy consumption as well as maintaining comfort of occupants. Section 4.3.3 dealt
with examining the impact of different passive strategies applied to the building, for
which, other parameters were kept constant as the base case, on the basis of which,
a certain strategy giving the finest outcome is chosen. However, if more than one
strategy is applied to a building, the result of these techniques do not just add up
to each other. They have different interactions with the environment. They might
behave differently when alone or when in conjunction with other parameters. Hence,
the effects of these strategies should be studied when applied together in order to
analyse their inter relationships and to come to a conclusion on the basis of their
S. F. Ali and D. Rakshit
Table 4.8 Results of provision of window glazing
Type
Double pane clear
glass
Triple pane clear
glass
Tinted glass Low-e glass
Minimum PMV −0.61
−0.59
−0.81
−0.63
Maximum PMV
0.85
0.82
1.06
0.77
Maximum PPD
20.55
19.25
28.86
17.47
recommended by standards (ASHRAE 2010; ISO 2005) and the curve dominates
towards the zone of positive PMV values, making the environment comparatively
warmer, and resulting in attaining a maximum PPD value because of that. However,
that maximum PPD value is still approximately equal to the upper limit of the required
PPD, even though the PMV value is a little beyond the maximum tolerable PMV
value.
Analogously, the window properties were modified according to the cases undertaken for the study and the simulation was run for each of them. The thermal comfort
indices obtained using the simulation analysis for each of the case were plotted
against each other and it was noticed that the PMV versus PPD curves of the cases
followed the same trend as depicted in Fig. 4.7, though with different PMV as well as
PPD ranges. The results of these cases are tabulated in Table 4.8. Both the PMV and
PPD values in each of the cases were observed to have comparatively shrunk down
and tended towards the ideal range, with a considerable shift from a cooler environment to a warmer one. This suggests that changing the glazing type to the cases
chosen can result in admitting the heat inside and restricting its flow to the ambient.
Moreover, comparison of the results of these cases revealed that the difference in
their magnitudes are due to the different thermal properties they possess, enlisted in
Table 4.7. Comparison of results against each of the cases suggests that the low-e
glass has a better performance since the maximum reduction in values were observed
in this case, while minimum improvement was observed in the case of tinted glass.
4.3.4 Optimal Solution for Maximum Thermal Comfort
Implementing passive design technologies in buildings have a huge impact on the
energy consumption as well as maintaining comfort of occupants. Section 4.3.3 dealt
with examining the impact of different passive strategies applied to the building, for
which, other parameters were kept constant as the base case, on the basis of which,
a certain strategy giving the finest outcome is chosen. However, if more than one
strategy is applied to a building, the result of these techniques do not just add up
to each other. They have different interactions with the environment. They might
behave differently when alone or when in conjunction with other parameters. Hence,
the effects of these strategies should be studied when applied together in order to
analyse their inter relationships and to come to a conclusion on the basis of their