Mineral wool is among the commonly used conductive insulation material for building insulation. Studies on insulated building envelope in temperate climate have shown potential energy savings towards attaining energy efficient buildings and sustainable built environment. To date, there is no empirical data on the benefits of insulated building envelope in warm humid tropical climate. Such data would provide commercial mileage to the insulation and building industries. Hence, the Center for Research and Innovation in Sustainable Energy (RISE) of Universiti Teknologi MARA has embarked on research collaboration with a local insulation manufacturing association. This paper presents the empirical findings on thermal and energy evaluation of mineral wool insulation under Malaysian sky condition. The objectives of the study are to evaluate the wholebuilding thermal and energy performance for mineral wool insulation at roof pitch for selected roof pitch angle, and finally to identify the optimum roof pitch angle due to the thermal and energy saving potential. The experimental works were conducted inside the Twin Energy Efficiency Test Cells inside the campus of Universiti Teknologi MARA, Shah Alam Selangor. Two test buildings named as Test Cell A and Test Cell B has identical building design with conventional envelope constructions. Test Cell A was the control unit while Test Cell B was later modified with the installation of mineral wool insulation of thickness 75 mm at roof pitch angle of 10 O , 15 O and 20 O . Both cells were installed with a normal 750 W split unit air-conditioning system. Identical automated outdoor and indoor data logging systems were installed inside both test cells for simultaneous data collection. For each roof pitch angle, ten days data from Test Cell A and Test Cell B were simultaneously and consecutively monitored in a 24-hour air conditioned (AC) mode. Ambient temperature for outdoor and attic were collected for the thermal performance analysis. Electrical data of current, voltage, power and energy consumption were collected and analysed for the building cooling energy performance. The thermal and energy performance of the mineral wool insulation were appraised by the cooling load savings. The findings identify the optimum roof pitch angle and conclude that the mineral wool insulation at roof pitch produces nominal thermal improvement but noteworthy energy savings. .Keywords-component; mineral wool insulation; roof insulation; thermal performance; energy performance I.INTRODUCTION Malaysia is in the climatic region of tropical rainforest and is hot and humid throughout the year. Daily temperature exceeds more than 25 O C for 58% of the time with a mean annual humidity of 83%. The high level of global solar radiation ranges from 12 MJm -2 day -1 to 21 MJm -2 day -1 [1]. For low-rise buildings in tropical equatorial climates, the roof has been identified as the envelope most exposed and receives more solar radiation than any other surfaces [2,3,4]. It is the major source of external heat gain ...

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For low-rise buildings in equatorial region, the roof is exposed to solar radiation longer than other parts of the envelope. Roofs are to be designed to reject heat and moderate the thermal impact. These are determined by the design and construction of the roofing system. The pitch of roof and the properties of construction affect the heat gain into the attic and subsequently the indoor temperature of the living spaces underneath. This finally influences the thermal comfort conditions of naturally ventilated buildings and cooling load of conditioned buildings. This study investigated the effect of insulated sloping roof on thermal energy performance of the building. A whole-building thermal energy computer simulation tool, Integrated Environmental Solution (IES), was used for the modelling and analyses. A building model with dimension of 4.0 m x 4.0 m x 3.0 m was designed with insulated roof and conventional construction for other parts of the envelope. A 75 mm conductive insulation material with thermal conductivity (k-value) of 0.034 Wm -1 K -1 was installed underneath the roof tiles. The building was modelled with roof pitch angles of 0°, 15°, 30°, 45°, 60°a nd simulated for the month of August in Malaysian climate conditions. The profile for attic temperature, indoor temperature and cooling load were downloaded and evaluated. The optimum roof pitch angle for best thermal performance and energy saving was identified. The results show the pitch angle of 0°is able to mitigate the thermal impact to provide the best thermal condition with optimum energy savings. The maximum temperature difference between insulated and non-insulted roof for attic (Attic A-B ) and indoor condition (Indoor A-B ) is +7.8°C and 0.4°C respectively with an average energy monthly savings of 3.9 %.

This paper presents the prediction of grid-connected photovoltaic (GCPV) system installed at Green Energy Research Center, Universiti Teknologi MARA, Shah Alam, Malaysia located at latitude of 2 °N 101°E. By using Mathematical approach and climate variations of Malaysia such as module temperature and solar irradiance, the prediction of power systems performance parameters was analyzed. The parameter of the study is limited to 26 consecutive days with filter data of 80W/m 2 irradiance. This study conducted by using monocrystalline and polycrystalline solar cell technologies. The actual and the predicted data measurement of these solar cell technologies were analyzed. The empirical models were compared according to the coefficient of determination (R 2) and percentage error. MathCAD software was used in order to calculate the prediction and detail analysis of electrical parameters. Finally, the results show a good accuracy between actual and prediction data.

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