Ardiyansyah Yatim

• University of Indonesia

Indonesia is a tropical country with relatively warm temperatures, so it is necessary to use air conditioning in daily activities. The use of the air conditioner causes the large use of electricity. This prompted the government to intervene by issuing the Minister of Energy and Mineral Resources Regulation No. 57 of 2017 regarding the provisions fo...

Air Conditioner has become one of the most increasing household appliance uses in Indonesia. The function of air conditioners is focused on providing thermal comfort to its users. Due to the increase in Indonesia's population, there is also an increase in energy usage. One use of consumptive electrical energy is the use of AC. This increase in ener...

Higher energy demands in favorable energy prices increasing people's affordability of the cooling devices, causing most building and residential areas to wear air conditioning systems. Higher energy saving, efficiency, and eco-friendly equipment have become a challenge for manufacturers and researchers. Also, Indonesia's government rules the energy...

Thermal comfort is an essential parameter for the well-being of occupants in buildings. This paper aims to analyze the thermal comfort of a 400-person capacity-art center auditorium at Universitas Indonesia. The physical parameters evaluated include temperature and humidity according to both ASHRAE-55-2010 and National SNI 03-6572-2001 standards on...

Many researches have been conducted on cooling equipment to reduce its energy consumption, maintenance and operation cost. Oil-free chiller uses a magnetic bearing compressor to avoid friction loss from the bearing’s contact surface. In comparison to a conventional compressor, the magnetic bearing of the motor, with the help of variable speed drive...

Consideration of energy consumption and its impact on the environment has been driving the heating, ventilating, and air conditioning (HYAC) industry to develop and test more energy-efficient units. The Air Handling Unit (AHU) is one of the important components of the HYAC system that has undergone a lot of improvements in terms of energy efficienc...

Correspond with population growth, Indonesia's energy consumption has been increasing for the past decade. In the last few years, the demand for energy increases by 7.1% every year. The highest energy consumption for a building is in the cooling sector. Much research has been conducted to increase the performance of cooling equipment to reduce thei...

Due to the high level of population of the Indonesian citizen affecting the necessities of the Indonesian citizen, one of which is the needs for electricity., the government through the Ministry of Energy and Mineral Resources made PERMEN ESDM number 7 of 2015 concerning the application of minimum energy performance standards and the inclusion of e...

Indonesia is the fourth most high population country in the world. This amount of population causes the electricity energy necessity much more. One of the common uses of electricity is for the usage of air conditioner which is part of the living standards in this generation. The government have created a regulation made by the Ministry of Energy an...

Here, we present a numerical approach to analyze the integrity of a vessel that was subject to a weld repair. A Post-Weld Heat Treatment (PWHT) process was implemented to a vessel undergone weld repair due to leakage. Due to the thick wall of the welded bottom head, this welding process must be followed by the PWHT to relieve the residual stress, a...

Air conditioner has been one of the main necessities for mankind, especially for people living in warm climate countries such as Indonesia. The need for air conditioner itself functions for the comfort of users and also operating functions of certain equipment. Due to global warming, increase in the temperature of the Earth forces greater energy co...

Residential air conditioning equipment has gained in public interest, primarily due to its huge energy consumption. Both in the US and Indonesia, this resulted in increased minimum efficiency standards. Manufacturers adhere to these standards through increased coil surface area, equipment size, and air flowrates for a given cooling capacity. While...

Air conditioner has been one of the main necessities for mankind, especially for people living in warm climate countries such as Indonesia. The need for air conditioner itself functions for the comfort of users and also operating functions of certain equipment. Due to global warming, increase in the temperature of the Earth forces greater energy co...

To maintain the integrity of the gas pipeline, the repairing of pipeline system with common method such as cut and replaces method by conducting hot tap and bypass or clamp method is conducted. Both methods require in-service welding in the process. During in-service welding, the process affects the structure strength. The structure then needs to b...

A cooling tower is a unit that helps the process of heat dissipation. Thus, thermal effectiveness is a vital variable for cooling tower performance. Scale precipitation can obstruct thermal effectiveness of the heat exchange unit due to its natural high thermal resistance properties. The ozonation process is expected to decrease the potential of sc...

Cooling towers are used to increase productivity and efficiency in industrial machinery. The formation of corrosion and humid grass inhibits the heat transfer system thus affecting the efficiency level of the cooling tower. This study aims to determine the effect of ozone usage on corrosion and bacteria in a closed cooling tower system. The method...

Waterjet propulsion is a type of propulsion system which is used widely by ship with high-speed operation and sailing in shallow waters. This system is constructed by pump and impeller that impels water passing through the inlet tube. Transport energy is occurred from pump to water, due to rotation of the impeller. Reduction of cross-sectional area...

Heat and mass transfer that occurs in liquid fuels, is a very important thing to know. It becomes an important thing to understand the basic elements of the spray droplet. Various models analogy of heat and mass transfer have been formulated to show the characteristics occurring within the system. The analogy model commonly used to obtain the value...

In the industrial world, the cooling tower is one of the tools used for cooling water circulation in industrial machinery. Inadequate cooling water can cause a machine, like a heat exchanger unit, to corrode or form scaling that will reduce effectiveness of the cooling tower system. This study aims to determine the effect of ozone performance and c...

The purpose of this paper is to examine energy efficiency through the study of performance in vapour compression cycle for auditorium in University of Indonesia using natural refrigerant R290. The installation of the chiller system which is the first in Indonesia within academic institution is particularly relevant in light of the gaining interest...

In refrigeration systems, oil is used to lubricate the moving parts of compressors. Unfortunately, oil is often miscible with refrigerants and it is inevitably discharged to condensers and evaporators. This paper investigated the retention of oil in microchannel type condenser and evaporator of a R134a refrigeration system for light commercial refr...

In air-source heat pump systems, lubricant is often used with refrigerant compressors and, a small portion of oil, which is inevitably discharged by the compressor, circulates with the refrigerant across the systems components. Oil tends to accumulate in heat exchangers, increasing the pressure losses and reducing the heat transfer capacity. In add...

The Stirling engine is an external combustion where the fuel combustion process takes place outside the cylinder. It offers flexibility of fuel used for the power generation, hence is a potential substitute to fossil fuelled internal combustion engine and contribute toward more sustainable power generation. In this study a Gamma V2-6 Stirling engin...

The Stirling engine is an external combustion where the fuel combustion process takes place outside the cylinder, at the combustion chamber or burner. Stirling engine offers flexibility of fuel used for the power generation hence is a potential substitute to fossil fuelled internal combustion engine and contribute toward more sustainable power gene...

Oil retention in a microchannel type condenser was measured and its effect on heat transfer rate performance and pressure drop were analyzed for refrigerants R410A and R134a condensation. The heat exchanger was a 2-pass aluminum louvered-fin type consists of multiports rectangular channels with hydraulic diameter of 0.06 inch (1.7 × 10⁻³ m). The re...

This study was aimed to elaborate fiscal instrument to support the development of the hybrid car in Indonesia. It focuses on three kinds of fiscal instruments available: the Luxury Goods Tax reduction, Customs Duty reduction/exemptions, VAT reduction (or tax borne by the Indonesian government). The study was consisting of impact analysis on oil con...

https://www.techstreet.com/standards/rp-1564-measurements-of-oil-retention-in-microchannel-heat-exchangers?product_id=1902641#jumps

An experimental investigation using a Peltier thermoelectric cooler (TEC) to cool down a cryoprobe for cryosurgery was performed. Two prototypes of cryosurgery devices consisting of 5- and 6-stage TEC modules were analyzed using a variety of electrical voltages, circulating thermostatic bath (CTB) temperatures, and heat exchanger configurations to...