CHAPTER - 1INTRODUCTION1.1. GENERAL INFORMATION Nowadays, as the population increases, the need also increases. Human being needs more comfort due to inferior environment (such as light, sound, heat producing machines). Sound, light and heat have a great influence on human comfort. They can negatively impact human comfort in a positive or negative way. The researchers suggest that the human body is used to feeling comfortable at a temperature between 22°C and 25°C. Anything less or more than this, the human body feels uncomfortable. This is because the human body is structured in such a way that it receives a certain amount of light, otherwise it can cause sunburn and other skin diseases. Refrigeration, the production of cold, is an essential practice for today. life. It is used in many places such as food processing and preservation, air conditioning for comfort, manufacturing of chemicals and other materials, concrete cooling, medical applications etc. Refrigeration is defined as the science of maintaining the temperature of a particular space lower than the surrounding space. Refrigeration and air conditioning involves various processes such as compression, expansion, cooling, heating, humidification, dehumidification, air purification, air distribution etc. In all these processes an exchange of mass, momentum and energy takes place. All these exchanges are subject to some fundamental laws. Therefore, to understand and analyze refrigeration and air conditioning systems, a basic understanding of the laws of thermodynamics, fluid mechanics, and heat transfer is essential. Refrigeration is the removal of heat from a space or body at a lower temperature than its surroundings. It should be kept in mind that the refrigeration… middle of the paper… refrigeration system can be built with capacities well in excess of 1,000 tons of refrigerant each, which is the largest size for single compressor units. Comparison between vapor compression and absorption systems. The comparison between vapor compression and absorption systems is shown in Table 1S.N. Absorption Cycle Compression Cycle1 Uses low quality energy such as heat. It uses high-quality energy such as mechanical work.2 The moving parts are only the pump, which is a small part of the system. So the operation is smooth. The moving parts are located in the compressor. Therefore, increased wear, deterioration and noise.3 The system can operate at lower evaporator pressures even without affecting the COP. COP decreases considerably as evaporator pressure decreases.4 Automatic operation for capacity control is simple. Automatic operation for capacity control is difficult.