Pressure Enthalpy Without Tears Manual
: ESCO Institute
Over the years, much has been written on the subject of pressure enthalpy. Although much of this material has been geared toward engineering and system design, this book presents the important concepts of pressure enthalpy in a manner that will appeal to the service technician. Each refrigerant has its own properties and these properties are compiled on the pressure enthalpy chart for that particular refrigerant. Pressure enthalpy charts should not be confused with pressure/temperature charts, which only provide information regarding saturated refrigerants. The pressure enthalpy chart enables us to create a complete picture, or "snapshot" of the entire system. With a completed pressure enthalpy plot, we can look at sensible and latent heat transfers, while looking at the major system components…all at the same time. The book starts by reviewing the basic vapor-compression refrigeration cycle, as well as the concepts of superheat, subcooling and the pressure/temperature relationship. The book then turns to pressure enthalpy and the p-h chart, giving an overview of the meaning and purpose for every line on the chart. Simplified charts are used to clarify the explanations. The plotting of actual systems follows next. With the completed plot in hand, we next turn to the evaluation of the system parameters that allow for the calculation of many system characteristics, including system capacity and system efficiency. Once we have learned to plot systems on the chart, we then start looking at systems that are operating with malfunctions such as dirty air filters, refrigerant overcharge, refrigerant undercharge, etc. It is here that the reader can appreciate the power of the pressure enthalpy chart and its usefulness to effectively and accurately start up, troubleshoot and evaluate air conditioning and refrigeration systems. ©2014 About the Author: Over the past thirty plus years, Eugene has been involved in all aspects of the HVAC/R industry from field technician and system designer to company owner, teacher, administrator, consultant and author. Eugene is presently the lead faculty member for the HVAC/R program at Suffolk County Community College in Brentwood, New York. Eugene has twenty years of teaching experience and has taught at Apex Technical School and Nassau BOCES. Eugene is particularly excited about his present position as an Assistant Professor at Suffolk County Community College, as this is the only institution on Long Island to offer, not only a one-year certificate in HVAC/R, but also a two-year Associates of Applied Science degree, A.A.S., in HVAC/R. Eugene earned his dual Bachelors Degree from The City College of New York and his Masters of Science degree from Stony Brook University, where he specialized in Energy and Environmental Systems, studying renewable and sustainable energy sources such as wind, solar, geothermal, biomass and hydropower. He earned his Certified Master HVAC/R Educator credential from HVAC Excellence and the ESCO Group after completing a battery of 7 educator-level examinations in a variety of content areas including Air Conditioning, Refrigeration, Heating, Heat Pumps and Electricity. Eugene also carries the BEAP credential issued by ASHRAE. This credential classifies Eugene as a Building Energy Assessment Professional. As an active member of both ASHRAE and RSES, Eugene served as the subject matter expert and wrote the production scripts for over thirty education videos directly relating to our industry in addition to authoring the number one HVAC/R textbook in the industry, "Refrigeration and Air Conditioning Technology, 7th Edition" published by Cengage Learning. This book is used in over 1,000 schools both in this country and abroad to help individuals learn, and master, the skills required to service, install, design, service and troubleshoot HVAC/R equipment. Other book credits include Refrigeration and Air Conditioning Technology, 6th Edition, Residential Construction Academy: HVAC, 1st and 2nd Edition, Pressure Enthalpy Without Tears (2006), Heat Pumps (2002) and, of course, Psychrometrics Without Tears (2013). Eugene has also written a number of articles for industry newspapers and magazines. Eugene was selected as one of the top three HVAC/R instructors in the country for the 2005/2006, 2006/2007 and 2007/2008 academic school years by the Air Conditioning and Refrigeration Institute (ARI), now AHRI, and the Air Conditioning, Heating and Refrigeration (ACHR) News.