ZEMCH 2015 - International Conference Proceedings | Page 621

Figure 4: Thermal comfort condition for brick walls with iron sheet (top) and thatched roofs (bottom).
4.3 Hollow concrete block walls with iron sheet/thatched roof
Hollow concrete block walls had a very poor performance in terms of thermal comfort. This was despite the fact that the thermal conductivity of hollow concrete blocks (0.86 W/m.K) was lower than
brick walls (1 W/m.K). The results indicated that hollow concrete block walls failed to satisfy thermal
comfort criteria regardless of roofing types. The situation, however, was considerably worse for the
iron sheet roof. According to the results, for hollow concrete block walls with iron sheet roof, the
building was thermally uncomfortable for 13.7% of the occupied periods which is significantly higher than the 3% acceptable level. Moreover, We exceeded the acceptable limit in 148 days which is
around 41% of the entire year. The maximum value for We was reported on the 24th of January with a
value of 35 °C.hr (degree-hours). The building also failed criterion 3 as there were 39 hours/incidents
during which ∆T exceeded the upper limit temperature (Tupp). Figure 5 summarises the results of
simulations for hollow concrete block walls with iron sheet and thatched roof construction methods.

Figure 5: Thermal comfort condition for hollow concrete block walls with iron sheet (top) and thatched
roofs (bottom).

Improving thermal comfort in low-income tropical housing: the case of Uganda

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