Browsing by Author "Kashif Irshad"

Now showing 1 - 7 of 7
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    Effect of air gap on perfomance enhancement of building assisted with photo voltaic systems
    (ARPN Journal of Engineering and Applied Sciences, 2016-10-10) Kashif Irshad; Khairul Habib; Kareem, M.W
    This paper investigates performance improvement of room assisted with Photo voltaic (PV) system by varying air gap and PV glazing type. PV panel was installed on the south side of the room as Photo Voltaic Trombe wall (PV-TW) and over the roof. Performance was evaluated in term of cooling load, energy consumption and PV efficiency. Three different types of PV glazing (i.e. Single Glazing, Double glazing, double glazing filled with Argon gas) was tested by changing air gap between wall and PV panel for Malaysian climate. TRNSYS building simulation software was used in which various input parameters were inserted to obtain the results. It was found that maximum PV efficiency was achieved in the case of Double glass filled with Argon PV-TW at air gap of 0.2 m and roof pitch angle 20 degree. Ventilated PV-TW and PV panel installed over the roof also reduces cooling load of the room. Among all the three types of glazing, room assisted with Double glass filled with argon PV panel shows highest reduction in cooling load at air gap 0.2m and roof pitch angle 20 degree. Also cooling load of room reduced significantly with the increase in roof pitch angle up to certain critical angle which is different for different PV glazing.
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    Evaluation of thermal comfort in a test room equipped with a photovoltaic assisted thermoelectric air duct cooling system
    (Elsevier, 2017-08-26) Kashif Irshad; Khairul Habib; Kareem, M.W.; Firdaus Basrawi; Bidyut Baran Saha
    This study investigates the comfort performance of a test room equipped with the southfacing photovoltaic wall (PV-W) and north-facing thermo-electric air duct (TE-AD) system for the tropical climate. Both subjective and objective measurements were used to analyze the TE-AD system cooling performance when operated at variable input current supply (2e7 A) from a PV system. Indoor radiant and air temperatures, relative humidity, and air velocity were measured based on ISO 7730 for objective measurement. For subjective measurement, forty respondents were required to fill up the questionnaire that developed based on UNI EN ISO 10551 and UNI EN ISO 7730 guidelines in order to access their thermal comfort opinion. The results show that the thermal response of respondents associated with indoor situation of the test room have changed from (þ1) slightly warm to cool ( 2) when the input current supply rises from 2 A to 6 A. The overall predicted mean vote, predicted percentage dissatisfied indices, and acceptability vote shows that more than 90% of the respondents were thermally satisfied. Integration of the PV-W system with the TE-AD system increases the thermal comfort and reduces the thermal load of the test room with other benefits includes less fuel and energy consumption, high reliability, and less maintenance operation.
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    Experimental investigation of double slope solar still integrated with PCM nanoadditives microencapsulated thermal energy storage
    (Elsevier, 2023-11-04) Lukmon Owolabi Afolabi; Christopher Chintua Enweremadu; Kareem, M.W.; Adiat I. Arogundade; Kashif Irshad; Saiful Islam; K.O. Oladosu; Abdulhafid M. Elfaghi; Djamal Hissein Didane
    Transparent covered slope solar stills are trending but characterised with low productivity, heat losses and high energy consumption, which are setbacks in practice. In this study, double slope solar still (DSSS) integrated with PCM-TES is presented. PCM was microencapsulated with epoxy resin composite using vacuum mould-filled techniques. Conventional DSSS and DSSS-TES data collected have been compared to establish the influence of TES on productivity. Daily average temperature of the glass cover, humid air, saline water, still basin absorber and TES cavity for the DSSS-TES attained are 65.2 ◦C, 77.5 ◦C, 82.4 ◦C, 79.5 ◦C and 68.4 ◦C, respectively. DSSSTES has yielded higher production, with 7.5 Litres of potable water daily and extension in operation period by 3 h has been achieved. In addition, condensation and evaporation rates increased with increase in production by 105%. Integration of TES with the system has reduced the heat losses while leakages from PCM nanocomposite have been prevented by microencapsulated insulator. No trace of metals, bacteria and organic contaminants has been found in desalinated water. A payback period of 0.8 year has been recorded based on all-year-round operations. Findings are in good agreement with existing models. Moreover, sensorial characteristics obtained conform to WHO standards.
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    Performance analysis of a multi-pass solar thermal collector system under transient state assisted by porous media
    (Elsevier, 2017-06-25) Kareem, M.W.; Gilani S.I; Khairul Habib; Kashif Irshad; Bidyut Baran Saha
    An enhanced forced convective multi-pass solar air heating collector (MPSAHC) system aided with granite pebble bed has been investigated in this present article. The air heating collector system was tested in the outdoor solar research site of Universiti Teknologi PETRONAS, Malaysia (4.385693° N and 100.979203° E). Transport pipe for movement of heated air around the system was eliminated in the design of the MPSAHC facility to minimise the thermal losses, pressure drop and the pumping cost of the hot air in the control volume. The daily ambient temperature and relative humidity range recorded during the repeated tests are 21.09–36.64 °C and 48.04–87.9%, respectively. The collector unit achieved a peak temperature of 80.29 °C while the optimum system air mass flow rate of 0.016 kgs−1 was applied. Despite high relative humidity of the environment, the stream of ambient air was heated to 48.53 °C, 57.75 °C and 71.19 °C at different positions in the MPSAHC which correspond to single pass, double pass and multi-pass effects, respectively. The porous matrix exhibited slow energy discharge at night time with air temperature difference of 14.27 °C at 18:00 h to 4.54 °C at 24:00 h over environmental air temperature. MPSAHC system delivered specific energy demand (SED) of 11.51 kWh kg−1 while the maximum thermal collector and daily average transient collector efficiencies of 72.59% and 36.38% were achieved, respectively. A good agreement has been established between reported studies and the present investigation. Although continuity of system operation at night was achieved using porous matrix but improvement is still needed to optimise the system performance.
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    Performance evaluation of a novel multi-pass solar air heating collector
    (Elsevier, 2016-12-04) Kareem M.W; Khairul Habib; Sopian K; Kashif Irshad
    In this present investigation, the performance of a new solar air heating collector of multi-pass mode is presented. The solar air heating system is theoretically modelled by applying energy balance expressions to reflect the network of convection and radiation heat flows. The theoretical analysis of the active air heater is supported by SIMSCAPETM numerical tool while the proposed multi-pass solar collector system was tested under the meteorological condition of Seri Iskandar, Malaysia (4.385693o N and 100.979203o E). These techniques were used to audit the solar energy balance of the solar dryer system. The performance indices of the drying system were evaluated and the system thermodynamic correlations were obtained. Daily maximum temperature gradient between ambient and the system collector was 30.42oC. The thermal collector efficiency and optical efficiency were 59.96% and 72.26%, respectively. Improvement on system thermal delivery by the sensible porous matrix of 9.37% was achieved. The predicted performance level was compared with the test result and a relatively fair agreement was obtained. However, the instantaneous thermodynamic properties of air at the system boundary need to be defined to accomplish better accuracy on the relevant correlations.
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    Study of thermoelectric and photovoltaic facade system for energy efficient building development: A review
    (Elsevier, 2019-05-17) Kashif Irshad; Khairul Habib; R. Saidur; Kareem, M.W.; Bidyut Baran Saha
    Energy usage in buildings has become a critical issue due to increase in occupants’ time spent inside a building and use of energy intensive equipment for providing comfort. Utilization of an alternate source of energy can be considered one of the promising solutions to tackle this issue. In the present paper, a review of photovoltaic (PV) and thermoelectric (TE) technologies implemented for energy efficient building development is presented, discussed and critically analyzed. Then, the basics of the solar panel and its performance parameters are introduced. After that, the integration of the PV technology in the building particularly on the wall and its benefits with respect to the building energy consumption has been thoroughly studied. It was found that about half of building thermal load was reduced by installation of a PV panel over the wall. In addition, the thermoelectric module as a substitute to the air conditioning technology is reviewed and literature that focuses on the integration of both TE and PV for building applications has been studied. It can be seen that the PV integrated with the TE system increases the energy saving potential by 22% and reduces 5e10 C indoor temperature from the ambient conditions. At the end of this article, few challenges, environmental aspect and future research directions are also addressed in detail.
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    Transient modelling of multi-pass solar thermal collector with sensilble energy storing matrix
    (ARPN Journal of Engineering and Applied Sciences, 2015-11-21) Kareem M.W; Khairul Habib; Ruslan M.H; Kashif Irshad
    Transient modelling of multi-pass solar hot air dryer as a physical system is presented in this present work. SIMSCAPE/SIMULINK tool was utilized for the theoretical study of hot air passing through transparent flat plates and anodized aluminium as solar thermal collector. Pebble bed made of granite was obtained locally to sever as the sensible heat reservoir. The thermal energy balance was resolved using lumped component technique. The parameters, variables and operating conditions of materials that constitute the thermal system forms the modelling input with available weather data collected in the Solar Research Site, Universiti Teknologi PETRONAS (4.385693o N and 100.979203o E). The model revealed improved on the multi-pass system performance efficiency by 12.4% and 10.1% when compared to the reported single pass and double pass solar air heaters. Closed loop control mechanism was imposed to achieve a steady heat flow 471.2 Js-1 to the drying compartment. A temperature gradient of 31.21 K was predicted which is suitable for the drying operation of many agricultural products. The theoretical result was in agreement with output obtained from the humidity controlled drying test system in the Solar Energy Laboratory, Universiti Kebangsaan Malaysia. However, there was need to improve the boundary condition accuracy and flexibility to accept various materials for system boundary.