A comparative study between unvented and vented attics powered by the hybrid turbine ventilator in Malaysian houses

Abstract

Vented attic is a design technique that provides a better solution to reduce solar heat gains trapped in a roof attic. However, its application in the tropical climate is very rare if not, ignored, especially in Malaysian houses. This paper seeks to identify, and compare the performance of attic ventilation by a single hybrid turbine ventilator for a specific volume under both unvented and vented conditions. The study was done in an actual roof attic (10 m3) located in Universiti Sains Malaysia. The results indicate that the reduction of the attic air temperature was 6.4°C, while stabilising the level of relative humidity to about 40–50% which is higher than that for an unvented attic by 10%. Furthermore, the findings reveal that by incorporating a 50 W poly-crystalline solar panel with a turbine ventilator of Ø 45 cm, the peak value of the attic air velocity had exceeded 1.3 m/s when the solar radiation was observed to be around 800 W/m2.