Petroleum is one of the natural resources that can produce energy both for fuel and for generating electricity. One of the most important and widely used equipment in this industry is a pump. A pump is a device for distributing fluids from one place to another. A centrifugal pump is a device for distributing move liquids from one place to another by converting the fluid's kinetic energy into potential energy through an impeller that rotates in the housing. The objective of this research is to analyze the damage of pump 024P108, which indicated high vibration due to using a high-speed shaft. The research is done by using an analytical method, using CFD Fluent analysis with flow discharge capacity under normal conditions and minimum flow conditions, and comparing the results by API 610. Afterward, the right maintenance will be known for the 024P108 centrifugal pump to reduce the high vibration that occurred in the pump. The pump is run at minimum flow with a flow rate of 22 m3/hr and the normal flow rate of the pump is 97.9 m3/hr so that the results show that the pump head has decreased to 198.74 m and the pressure drop has increased by 2.5995×105 Pa. The vibration test data shows that high vibration of 8.5 mm/s is produced by a minimum flow state of 22 m3/hr, this low fluid flow is the cause of high vibration on the pump. High vibration has an impact on pump performance, that is decreasing pump performance (efficiency) and if left continuously it can cause damage to the pump.

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Pemanfaatan Pembangkit Listrik Tenaga Surya (PLTS) Off-Grid memerlukan baterai sebagai media penyimpanan energi yang dihasilkan dari modul photovoltaic (PV). Baterai perlu mendapat perhatian khusus karena kerusakannya disebabkan penggunaan yang tidak ideal dan baterai tidak dilengkapi sistem proteksi dan monitoring, yang dapat mengurangi performa dari baterai. Pada Skripsi ini dilakukan monitoring 2 jenis baterai sel sekunder yaitu Lead Acid 12 V dan Lithium 12 V untuk sistem PLTS off grid 100 Wp menggunakan metode kuantitatif, yaitu pengukuran SOC (State Of Charge) dengan metode modified Coulomb Counting. Sensor tegangan, sensor arus ACS712 digunakan untuk mengirimkan informasi mengenai kondisi baterai ke mikrokontroler Arduino uno R3 sebagai pengolah data. Pengukuran SOC dengan metode ini dilakukan dengan menjumlahkan muatan yang masuk atau muatan yang keluar dari baterai dalam kurun waktu tertentu. Perhitungan coulomb inilah yang nantinya didapatkan nilai SOC baterai. Dari pengujian yang telah dilakukan, alat mampu membaca nilai tegangan, arus, SOC dengan baik. Hasil pembacaan parameter ditampilkan pada LCD. Sistem proteksi akan aktif ketika baterai dalam kondisi tidak ideal, yaitu ketika SOC baterai bernilai 100% pada saat proses charging dan 20 persen saat proses discharging, sehingga baterai tidak mudah rusak.

Refrigerant R410A is a cooling barrier that is still widely used for air conditioning. This R410A contains the Fluoro element which can increase the value of GWP. In this research simulation, we used an AC unit using R410A with the aim of reducing GWP (Global Warming Potential) by mixing synthetic refrigerant with hydrocarbons. R410A still has content GWP: Mixing using R32 / R1270 refrigerant is predicted to reduce the GWP value because R1270 is one of the hydrocarbon refrigerants that has a GWP value of only: 3. By using Refprop software it can be simulated a mixture composition starting from 50/50, 40/60, 30/70, 20/80 and 10/90. From the results of the mixture simulation conducted, obtained a mixture approaching the characteristics of R410A, namely in the mixture: 20/80 with COP: 5.17 while R410A: 4.12. Compression ratio: R410A: 2.0 and for mixed refrigerants 20/80: 1.9. The refrigerant effect of mixed refrigerants is 20/80: 254,51, R410A: 162,77. Using this refrigerant mixture can reduce the GWP value and improve the performance of the AC cooling system. This refrigerant has considerable potential to replace the R410A.

HVAC installations are essential to the operating room to maintain the safety of environmental conditions and provide comfort for patients and medical personnel. Operating room is a room with a class of 10,000 where the maximum number of particles in the room is 352,000 particles per cubic feet for bacteria 0.5-micrometer size (ISO 14644-1). To achieve the desired air conditions in the operating room required an air conditioning tool that is Air Handling Unit (AHU). The AHU determination shall be adjusted to the cooling load of the chamber derived from the sensible load and latent load. Exergy analysis is required to optimize a process and evaluate the device performance. The purpose of this study is to calculate the cooling load and perform the analysis of exergy destruction on Cooling Coil and Electric Heater in AHU. The calculation of cooling load uses the standard air change method. Exergy analysis uses the second law of thermodynamic concepts related to entropy. The results obtained cooling load and exergy destruction increases with the increase of ambient temperature. Maximum exergy destruction in cooling coil 1 and 2 at 35°C is 3.3 kW and 1.6 kW while in the electric heater is 0.52 kW.