The Optimization of Building Energy Consumption in Universitas Negeri Padang Using Building Energy Simulation Program

Energy consumption of a building is one of the biggest sources of energy use today. Green Building Comitte Indonesia (GBCI) has launched a concept of energy consumption saving in a nationally standard building. Audit Building energy audit is the way to know how actual building energy consumption is and find alternative solution to decrease energy consumption in order to fulfill the energy saving building criteria. Two types of HVAC systems will be run in the EnergyPlus simulation, split AC and central AC. The previous research proved that central AC is better than split AC system for energy saving in the building with 20 floors. The simulation results show that by using a certain energy system, a more efficient energy system will be achieved and can still maintain the comfort of the room at a temperature of 24 °C and relative humidity according to the Green Building Indonesia standard reference.

Characteristics Particleboard Made From Areca Fiber With Tapioca and Gambier Adhesive

The development of engineering materials has increased its use in various fields. The engineering material is particleboard made from areca fiber which is processed with technology. Areca fiber as waste has the potential to be used as an engineering material. The purpose of this study was to obtain the characteristics of the particleboard following the quality standards of JIS A 5908-2003 and SNI 03-2105-2006. The process of making particleboard by mixing particles of areca fiber and adhesive then compacting it. The adhesives used are tapioca and gambier. The concentration of areca fiber particles is 90%, 80%, 70%, and 60%. From this research, it was found that the characteristics of the particleboard using tapioca adhesive according to the quality standard and the gambier adhesive particle board did not meet the standard quality. This particleboard can be used as a raw material for making interior furniture instead of wood.

Optimization of Waste Cooking Oil’s FFA as Biodiesel Feedstock

Waste cooking oil has high Free Fatty Acid (FFA). It affected on decreasing a biodiesel production. FFA reduction is one of important processes in biodiesel production from waste cooking oil. Thus, this study aimed to examine the optimum condition in FFA reduction. The process is assisted by using ultrasonic irradiation on acid esterification. Variables of the process are acid concentration, molar ratio of methanol and oil, and irradiation time. Meanwhile temperature irradiation on 45oC is a control variable. Process optimization is conducted by Response Surface Methodology (RSM) with Central Composite Design (CCD). The optimum conditions of response were 7.22:1 (methanol to oil molar ratio), 0.92% wt H2SO4, 26.04 minutes (irradiation time), and 45oC (irradiation temperature). Ultrasonic system reduced FFA significantly compared to conventional method.

Performance Analysis of Water Heating System by Using Double Glazed Flat Plate Solar Water Heater

Nowadays, the use of solar energy is incredibly important to be increased since solar energy is renewable energy and also does not cause pollution. To harness solar energy, a solar collector device is needed to convert solar energy into heat energy. This study aimed to analyze the heat transfer in the flat plate solar collector which is used as a source of thermal energy in the water heating process for bathing. A double-glazed solar collector was used to absorb solar thermal energy and then transferred it to a water pipe. The pipe material used copper which has a very high conductivity value with an outer diameter of 15.7 mm. The plate collector used aluminium plates because they have high thermal conductivity. The dimensions of the collector frame were 150 cm long, 80 cm wide and 80 cm high. The collector frame was made of wood and covered with an insulator from coconut fibre with a thickness of 8 cm, with a tilt angle of 15˚. Based on the experimental process, the collector temperature was taken by using a thermocouple in order to heat the water which the inlet temperature in a bucket was 28˚C and the outlet water temperature during the experiment was 40˚C.

The Effect of Tilt Angle of Axial Fan Blades on Air Flow Distribution in the Cabinet Dryer: Simulation Study Using Computational Fluid Dynamics

The application of tray dryer is widely used for various commodity dryers due to its simple construction. However, one of the drawbacks of tray dryer is the uneven airflow distribution in the drying chamber which results in the drying rate in the tray position being unequal. As a result, the degree of dryness of the product also varies. This study investigated the effect of fan blade angle on airflow distribution in the dryer cabin through numerical simulations. The axial fan diameter was 350 mm with a thickness of 20 mm. The variations of axial fan blades used were 10o, 20o, 30o and 45o. The number of blades used was 4, and the allowable airflow limit was 2 m x 1 m x 1 m, with an axial fan rotation of 500rpm. Based on the simulation results, the 45o fan angle had good air distribution results compared to the 10o, 20o, and 30o fan angles. Likewise, the distribution of air produced by the fan was evenly distributed, because the greater the angle of the fan used for the dryer, the better the results would be obtained.

The Effect of AC (alternating current) and DC (direct current) on Bend Testing Results of Low Carbon Steel Welding Joints

The purpose of this study was to determine the effect of alternating current (AC) and direct current (DC) on the bend testing results of low carbon steel welding joints. The results of this study are expected to determine the cracks that occur from the root bend and face bend testings in the AC and DC welding process. This study used experimental method, where the research was done by giving AC and direct polarity DC (DC-) SMAW welding treatments. The material used in this research was low carbon steel plate DIN 17100 Grade ST 44, thickness 10 with E7016 electrode type. The process of welding joints used a single V seam, strong current of 90A, and the welding position of 1G. The testing of welding joints was carried out by bend testing using the standard acceptance of AWS D1.1 root bend and face bend testing results. The results of the bend testing showed that the AC welding root bend test specimen held no cracks while the DC welding root bend test held cracks with incompelete penetration and open crack defects. On the contrary, the AC welding face bend test had open crack defects and in the DC welding face bend test was found a crack. Thus, there was a difference in the crack resistance of the welding joint from the types of current used through the root bend test and face bend test. Therefore, it can be summarized that AC welding is better for root welding and DC welding is good for capping welding.

The Effect on Using Different Types of Electrodes toward the Tensile Strength of the Welding Joints Groove V Low Carbon Steel Type DIN 1.0038

The choice of electrode type in welding will affect the strength of the welding result. The aim of this study was to determine the effect on using different type of electrode on the tensile strength of low carbon steel type 1.0038 by using experimental method. The welding was conducted using Groove V. In addition, the specimens used in this research were the low carbon steel plate type 1.0038 with a thickness of 8 mm and were given SMAW treatment using 2 different types of electrodes, namely E 6013 and E 7016 whose diameters were 2.6 and 3.2 mm. The standard specimen used was ASTM-E8 and being tested using a Universal Testing Machine. Based on the research that had been conducted, it was obtained that the steel type 1.0038 welded using E 7016 electrodes had a higher tensile strength than the one using E 6013.

The Effect of Cast Iron Preheating on the Microstructure of Welding Results by Using Cin-2 Electrodes

Cast iron is commonly found in engineering tools such as machine frames, vise, lathes, planers, pressing tools, V-belt pulleys and others. Cast iron is a metal which is relatively difficult to weld because it contains more than 0.3% carbon. As a matter of fact, a lot of welding workers still experience failure in welding the cast iron, so they require the proper procedures to perform welding on the cast iron like the heat treatment before the welding. This study was aimed at obtaining the effect of preheating variations on the weld joints in which the process of welding the material used the type of open V seam connection. The specimen used was a cast iron with a thickness of 10 mm and the electrode used was the JIS Z 3252 DFCNiFe electrode. The method applied in this research was the microstructure observation testing toward the welding result by using Shielded Metal Arc Welding (SMAW). Based on the results of the study, it can be concluded that by applying the preheating variation treatment on the cast iron welding, there was a change in the microstructure and it was dominated by pearlite-ferrite in the weld metal area. As a result, the rough graphite that looks like roots became smooth after experiencing the preheating treatment because the ferrite was evenly distributed in the heat affected area. To conclude, the most superior specimen for the cast iron preheating among the four specimens was the one with 425oC temperature.

The Effect of Cooling Media on Tensile Strength of Medium Carbon Steel in Post Welding Process Using Electric Welding (SMAW) with E7018 Electrodes

The use of cooling media in post welding process will affect the tensile strength of a material. This study aims to determine how much the influence of using cooling media in post welding and which cooling media is appropriate to use. The process is done by comparing the tensile strength of each cooling media, namely the cooling media of water, air, and coolant. The use of cooling media is carried out after the welding process, until the material that is ready to be welded reaches room temperature. Based on the experiments that have been conducted, the use of post-welding cooling media affects the tensile strength of medium carbon steel with the highest effect on the water cooling media, then the coolant media, and the lowest is the air cooling media. Therefore, the choice of the use of cooling media significantly affects the tensile strength of medium carbon steel in the post-welding process.

The Effect of Preheating and Non-Preheating in Cast Iron Welding Toward Mechanical Properties

Cast iron material is a material that has brittle properties and is less able to withstand stress due to the welding cycle caused by flake graphite in cast iron. Because of these problems, in connecting cast iron materials using the SMAW welding method, it is necessary to have heat treatment (preheating) to avoid the welding problems on the properties of cast iron. The purpose of this study is to determine the effect of heating and non-heating on the cast iron before the welding process. Therefore, this research will play a crucial contribution as a reference for cast iron welding researchers and cast iron welding process. The method of the research was experimental research, where the measurement results were obtained directly from the specimens. The welding was using an open V seam. The specimen used was cast iron with a thickness of 8 mm. One cast iron was given heat treatment at a temperature of 260ºC and the others did not receive heat treatment before being welded. The welding process used SMAW with CIN - 2 electrodes with a diameter of 3 mm. The test used the bending test on the face specimens according to the American Welding Society D1.1 standard. The results showed that there was an effect of the preheating treatment on cast iron, which that the non-preheating specimens were easier to fracture than the preheating specimens. Thus, it can be concluded that welding with preheating is better than welding without preheating.