International Journal of Marine Engineering Innovation and Research, Vol. 3(3), Mar. 2019. 84-92 (pISSN: 2541-5972, eISSN: 2548-1479) 84 Waste Heat Recovery from Exhaust Gas and Cooling Water as Water Heater on Domestic System of a Cruise Ship 48 meters Sutopo Purwono Fitri 1 , Agoes Santoso 2 , Nizar Febri Anggriawan 3 (Received:04 February 2019 / Revised: 11 March 2019/ Accepted: 26 March 2019) Abstract⎯cruise ship is a ship used for recreational and entertainment purposes. As a means of vacation and entertainment, the design of this transportation requires more attention. The design of the ship itself must be able to make it comfortable for the passengers. One of them, to increase comfort for cruise ship passengers is by adding heating water to the domestic system. Will need a large amount of electrical energy if using an electric heater. While in the engine room there is exhaust heat that can be utilized. The purpose of this research is to plan the utilization of waste heat contained in the exhaust gas and cooling water system (high temperature) as a water heater on the domestic system. The method used is the analysis of calculations. From the results of the calculation analysis, it was found that the hot water requirements of this ship were 3409 liters/day and needed a heat 167.12 kJ/s to increase the water temperature from 25 o C to 66 o C. From the calculation results, the 50% load engine has a heat 469 kJ/s, 75% load engine has a heat 645 kJ/s, 80% load engine has a heat 729 kJ/s, 100% load engine has a heat 781 kJ/s, while in cooling water system (high temperature) has a heat 252 kJ/s. Tank insulation using glass wool with a thickness of 610 mm. While the insulation on the pipe uses glass wool with thickness 50 mm. By replacing the electric water heater by utilizing heat waste can minimize the cost up to Rp.245,211.833/day or Rp.7,356,355.008/month. Keywords⎯ domestic system, waste heat recovery, water heater. I. INTRODUCTION The cruise ship is a ship that is used specifically for recreational and entertainment purposes. As a means of vacation and entertainment, the design of this transportation requires more attention. The design of the ship itself must be able to make it comfortable for the passengers. One of them, to increase comfort for cruise ship passengers is by adding heating water to the domestic system. In obtaining hot water on domestic systems on ships there are several ways by using electricity, gas, and solar power. Electricity consumption for the operation of electric water heaters on ships requires a large amount of energy and costs are expensive. Whereas if using solar power the cost that must be spent is far more expensive than using an electric water heater. While in the engine room there is wasted heat formed from the engine and other components. At present day there are many technologies that utilize waste heat energy to be used as the turbocharger, refrigeration, and desalination. So to obtain hot water without using electric water heater and solar power, it is a planned system that exploits waste heat for a domestic system in a ship. By utilizing this waste heat indirectly we can reduce the need for electricity usage [1-4]. Sutopo Purwono Fitri, Department of Marine Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia, Email: spurwono@yahoo.com Agoes Santoso, Department of Marine Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia, Email: agoes@its.ac.id Nizar Febri Anggriawan, Department of Marine Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia, Email: nizar.febri@gmail.com II. METHOD A. Waste Heat Waste heat recovery is one example of energy savings which aims to improve the efficiency of fuel use. In diesel engines, there are 3 main heat sources that can be utilized, including exhaust heat generated from jacket water, exhaust gas, and also from cooling water [1-4]. Factors affecting Waste Heat Recovery as follows: 1) Heat Quantity Heat quantity is the amount of heat energy contained in waste heat. 2) Waste Heat Temperature Waste heat temperature is a factor that determines whether the temperature of the exhaust heat can be utilized. 3) Waste Stream Composition Waste stream composition is a chemical content found in waste heat, which can affect the material and recovery process. 4) Minimum allowable temperature limit B. Heat Transfer Heat transfer is the process of transferring heat or heat caused by temperature differences. Where heat will move from high temperatures to lower temperatures. This transfer process will continue until there is a temperature balance in both media [5-10]. The process of heat transfer can be divided into three, namely as follows: 1) Conduction Conduction heat transfer is heat transfer that occurs on a solid medium, or on a silent fluid. Conduction occurs due to temperature differences between one surface and another on the media. 2) Convection