Moist air at 50c dry bulb temperature and 32% relative humidity enters the cooling coil of a dehumidification kiln heat pump system and is cooled to a temperature. W h carrier, rational psychro metric formulae, psychrometric chart, invention of centrifugal. Psychrometric processes unm mechanical engineering. In the domestic and industrial air conditioning applications some psychrometric processes have to be performed on the air to change the psychrometric properties of air so as to obtain certain values of temperature and humidity of air within the enclosed space. Psychrometrics is required to properly calculate heating and cooling loads, select equipment, and design air. This line represents the psychrometric process of the air as it passes through the conditioning plant. Cooling is the transfer of energy from the space or air supplied to the space by virtue of a difference in temperature between the source and the space or air. The psychrometric values were based on the oncoil and offcoil drybulb and wetbulb temperatures as indicated in the diagram. The important processes that air undergoes in a typical air conditioning plant are discussed below. The psychrometric chart psychrometric properties in ees. Pdf analysis of airconditioning and drying processes.
Psychrometric processes 721 mechanical engineering me462562 sustainable energy. Lecture 02 psychrometric processes of air conditioning systems free download as powerpoint presentation. A useful tool for studying and analyzing thermodynamics properties of moist air is the psychrometric chart. Proper knowledge of the psychrometric properties of air is essential in the design and operation of various food. Air conditioning and psychrometrics in airconditioning system, the air must undergo one or several of the following processes.
Diemuodeke department of mechanical engineering, university of port harcourt, p. This process is represented by a straight vertical line on the psychrometric chart starting from the initial value of relative humidity, extending upwards and ending at the final value of the relative humidity. Mago2 abstract the use of computational tools such as mathcad or microsoft excel to increase the level of conceptual understanding of psychrometric processes in buildings in an air conditioning technical elective course is explored. Psychrometrics is the study of the air and water vapor mixture. Air conditioning psychrometrics continuing education for. Psychrometric processes 521 mechanical engineering. Psychrometric processes for heating and air conditioning. The psychrometric chart psychrometric properties in ees air conditioning processes. Blackburn, pe, mba course content introduction if hvac problems and challenges are to be properly diagnosed and designed, it is essential that the psychrometric chart and psychrometrics in general be clearly understood. Analysis of air conditioning processes is required for maintaining proper temperature and humidity in living space such as residential, commercial, and industrial facilities. When properly used, however, it provides valuable information about the properties of air. This template allows a designer or operator to work backwards from a desired room relative humidity to the desired condition of the air as it. Steadystate psychrometric analysis of hvac circuits ibpsa. These are the best method to evaluate the capabilities of your employees.
Psychrometric chart fundamentals and its application to. The process in which the moisture or water vapor or humidity is added to the air without changing its dry bulb db temperature is called as humidification process. The analysis of psychrometric processes is performed by considering a control. Air conditioning engineers use the psychrometric chart to predict changes in the environment when the amount of heat andor water in the air changes. There are four basic processes for summer and winter air conditioning systems. How to show heating, cooling, humidificaton, dehumidification and adiabatic saturation processes on a psychrometric chart.
These analysis include summer air conditioning cycle and winter air conditioning cycle which may cover the four basic combined processes discussed previously. Based on their size, construction, and operating characteristics, airconditioning systems can be classi. Psychrometrics can be used to predict changes in the environment when the amount of heat andor moisture in the air changes. Air conditioning processes illustrated on a psychrometric chart. Psychrometric chart fundamentals and its application to hvac troubleshooting by. Lesson 26 psychrometric chart and its application 118124 lesson 27 psychrometric processessensible heating, sensible cooling, humidification, dehumidification and mixing of air 1252. All data essential for the complete thermodynamic and psychrometric analysis of air conditioning processes can be summarized in a psychrometric chart. Proficiency in the use of the psychrometric chart is an important tool for designers of air conditioning systems. Ashrae is the american society of heating, refrigeration and airconditioning engineers. The book air conditioning principles and systems written by edward g. Air conditioning processes 31 introduction 31 heating and cooling process 32 cooling with dehumidification.
Chapter 2 psychrometric chart humidity relative humidity scribd. Sensible cooling and heating when air is heated or cooled sensibly, that is, when no moisture is added or removed, this process is represented by a horizontal line on a psychrometric chart. Chapter tw o p sychrom etrics of a ir c ondition processes chapter two psychrometrics of air condition processes 2. Air conditioning processes heating process the heating process adds sensible heat to the system and follows a constant, horizontal moisture line. Psychrometric processes for buildings in an air conditioning course rogelio luck1 and pedro j. Air conditioning psychrometrics in air conditioning system, the air must undergo one or several of the following processes. American society of heating, refrigerating and airconditioning engineers temperature relative humidity winter. Figure 10 illustrates a fan system with a heating coil. Analysis of airconditioning and drying processes using.
Handbook of heating, ventilation and air conditioning. Psychrometric chart based on a barometric pressure of 101. Use of a psychrometric chart will show that this is true. In practical applications, the most common psychrometric analysis made. Psychrometric chart air conditioning processes youtube. Airconditioning processes are usually shown on a psychrometric chart, which was developed in the early 1900s by german engineer richard mollier. The psychrometric chart properties of air at first glance, the psychrometric chart appears to be an imposing network of lines. Use chart to analyze processes involving moist air. It is intended that the reader understands the simple operation of the systems, but does not address the process of the plan in detail. Psychrometric processes or air conditioning processes 1. Sensible heating it is addition of heat to moist air without the addition of moisture. The use of computational tools such as mathcad or microsoft excel to enhance the students understanding of the physics behind psychrometric processes in buildings in.
The psychrometric chart figure 1082 is a tool for understanding the relationships between the various parameters of supply air and the relative humidity. In the usual cooling process air is circulated over a surface at a low temperature. Analysis of air conditioning processes introduction moist air is a mixture of dry air gases such as o 2, n 2, co 2, etc and water vapour. Psychrometric processes 721 mechanical engineering. Psychrometric analysis and air conditioning cycles. Chapter 6 on psychrometrics presents examples involving the same type of problems, along with the theory, principals, and calculations involved in solving the examples manually using a psychrometric chart. Air conditioning principles and systems by edward g. The conservation of mass and energy is used in the study of air conditioning processes. Governing equations following the works of 10, 11, 12, the basic psychrometric. Using interactive psychrometric charts to visualize and.
All the types of problems related to the psychrometric chart are covered in this video, like problems on sensible heating, sensible cooling, humidification, dehumidification and on properties of. Lecture 02 psychrometric processes of air conditioning. Easily plot hvac and other psychrometric processes while out in the field, save the graphs, and then email the graph and results to yourself or clients. Air water vapor mixtures part ii the psychrometric chart and airconditioning processes we notice from the development in section a that the equations relating relative and specific humidity, temperature wet and dry bulb, pressure air, vapor and enthalpy are quite tedious and inconvenient.
Air conditioning and psychrometrics in air conditioning system, the air must undergo one or several of the following processes. It follows a constant humidity ratio line on the psychrometric chart. Use the psychrometric chart as a tool to determine the properties. Sensible cooling and sensible heating of air psychrometric processes in the domestic and industrial air conditioning applications some psychrometric processes have to be performed on the air to change the psychrometric properties of air so as to obtain certain values of.
Pdf psychrometrics of air condition processes venkitaraj. During this session, the psychrometric chart and its use in solving many air conditioning problems will be explained. Analysis of airconditioning and drying processes using spreadsheet addin for psychrometric data. This warming and cooling of the air is usually referred to as winter and summer air conditioning.
The temperature of air in airconditioning application ranges. Humidification the section on typical air conditioning processes shows winter and summer schematic diagrams and psychrometric charts. Chapter 2 psychrometric chart free download as powerpoint presentation. A psychrometric chart provides a convenient way to look at the air conditioning processes and it will answer why heated air can hold more moisture, and conversely, how allowing moist air to cool. The various psychrometric processes involved in air conditioning to vary the. Applying this notation to the heating problem from lecture 37, q m h h h h a a w a w.
This book is all about cooling systems and different principles used for cooling in buildings of large scale as cooling systems are very important in construction and design of a buildings therefore students of civil. A psychrometric chart also helps in calculating and analyzing the work and energy transfer of various airconditioning processes. This book is taught to students of civil engineering. Use of computational tools to enhance the study of. Psychrometric chart an overview sciencedirect topics. Mechanical engineering me462562 sustainable energy. When air is heated by a steam or hot water coil, electric heat, or furnace, no moisture is added.