4 Utilising Passive Design Strategies for Analysing Thermal …
53
Fig. 4.8 PMV versus PPD
curve for optimised case
compared to base case
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
Base Case
Optimised Case
objectives. The study involved analysing the effect of provision of wall insulation
and provision of roof insulation, both of which yielded fiber glass insulation in each
of their cases as the best among other options on the basis of maximum improvement
in thermal comfort of the occupants. Similarly, low-e glass windows provided better
results as compared to the other cases. However, for analysing the inter relationships
of these parameters, a combination of each of the type of window glazing was checked
and simulated with each of the case of provision of insulations in order to maximize
the thermal comfort goal. The simulation was run for the each combination and
the results in the form of thermal comfort indices was obtained. On comparing the
simulation results with each other, it was learnt that although individual strategies
applied showed different results, but if those strategies are used in conjunction, the
maximum improvement in comfort conditions was for the case of cellulose foam
wall insulation with fiber glass roof insulation of 40 mm thicknesses each, along with
triple pane clear glass window. The results of this case has been plotted in Fig. 4.8,
which depicts that there is a reduction in the minimum as well as maximum PMV
values, as compared to the base case. The minimum PMV value has reduced from −
1.22 to −0.31, while the maximum PMV value has decreased from 1.11 to 0.84. It
can be observed that when only individual strategies were taken into consideration,
the results with respect to the type of the insulation or glazing provisions were
different. However, when these strategies are combined, better results were obtained
with different type of insulation and glazing combination, rendering it as an optimal
solution for the cases studied. The combined effect of these strategies was that it
reduced the coolness in the inside zone and brought its minimum value down to −
0.31, which is within the ideal environmental condition (ASHRAE 2010; ISO 2005),
whereas, while doing that, the combined strategy led to shifting of the zone more
towards a warmer side for most of the instances, hence, most of the values of the
curve lie on the positive side of the PMV scale. Consequently, the PPD value too
dropped substantially, reaching to a value of 19.81% from 36.61%, indicating that
a larger percentage of occupants would be satisfied with their thermal environment.
53
Fig. 4.8 PMV versus PPD
curve for optimised case
compared to base case
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
Base Case
Optimised Case
objectives. The study involved analysing the effect of provision of wall insulation
and provision of roof insulation, both of which yielded fiber glass insulation in each
of their cases as the best among other options on the basis of maximum improvement
in thermal comfort of the occupants. Similarly, low-e glass windows provided better
results as compared to the other cases. However, for analysing the inter relationships
of these parameters, a combination of each of the type of window glazing was checked
and simulated with each of the case of provision of insulations in order to maximize
the thermal comfort goal. The simulation was run for the each combination and
the results in the form of thermal comfort indices was obtained. On comparing the
simulation results with each other, it was learnt that although individual strategies
applied showed different results, but if those strategies are used in conjunction, the
maximum improvement in comfort conditions was for the case of cellulose foam
wall insulation with fiber glass roof insulation of 40 mm thicknesses each, along with
triple pane clear glass window. The results of this case has been plotted in Fig. 4.8,
which depicts that there is a reduction in the minimum as well as maximum PMV
values, as compared to the base case. The minimum PMV value has reduced from −
1.22 to −0.31, while the maximum PMV value has decreased from 1.11 to 0.84. It
can be observed that when only individual strategies were taken into consideration,
the results with respect to the type of the insulation or glazing provisions were
different. However, when these strategies are combined, better results were obtained
with different type of insulation and glazing combination, rendering it as an optimal
solution for the cases studied. The combined effect of these strategies was that it
reduced the coolness in the inside zone and brought its minimum value down to −
0.31, which is within the ideal environmental condition (ASHRAE 2010; ISO 2005),
whereas, while doing that, the combined strategy led to shifting of the zone more
towards a warmer side for most of the instances, hence, most of the values of the
curve lie on the positive side of the PMV scale. Consequently, the PPD value too
dropped substantially, reaching to a value of 19.81% from 36.61%, indicating that
a larger percentage of occupants would be satisfied with their thermal environment.