Print this page Overview of Refrigerants Selection
A. Bhatia, B.E.
Course Outline
The release of refrigerant vapors into the atmosphere has the potential for ozone depletion in the stratosphere. In 1989, a scientific assessment of ozone depletion and global warming potential showed that the chlorine loading in the refrigeration is the culprit and recommended the use of refrigerants with very low or zero loading of chlorine.
This 2- hour course will introduce you to the issues surrounding refrigerants and is intended to be used as guideline to the responsible selection and use of refrigerants in vapor compression refrigeration systems.
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.
Learning Objective
Following completion of the course, the reader will understand:
- The differences between primary and secondary refrigerants;
- The phenomenon of ozone layer depletion and its relationship to various refrigerants;
- The criteria used in refrigerant selection;
- The thermo-physical, environmental and economic properties of refrigerants;
- The numbering system used for designating refrigerants;
- The international treaties and regulation in force on choice of refrigerants; and
- The available options for the replacements for CFCs and HCFCs.
Intended Audience
This course is applicable to mechanical engineers, HVAC engineers, facility engineers, architects, environmentalists, energy auditors, operations and maintenance personnel, as well as consultants and contractors who construct, build and manage facilities.
Benefit to Attendees
This course will help readers gaining a basic understanding of how to select and use refrigerants responsibly.
Course Introduction
There is no question that both the quantity and quality of outside air are crucial to the comfort of occupants in air conditioned buildings and the efficacy of the air conditioning of an entire building when related to comfort may be negated by the introduction of too little or poor quality outside air. Of course when designing low energy buildings there is a pressure to minimise outdoor air in order to keep plant size small and running costs low. This subject has therefore been the recipient of a huge amount of research throughout the world since the inception of modern air conditioning and is as important now as it has ever been particularly as modern buildings are becoming more ‘tight’ and outdoor air quality, in particular in urban areas, poorer in quality.
Use of ozone generators that purposely inject ozone in the space is one such technology being promoted by manufacturers and vendors. Independent studies by the Environmental Protection Agency (EPA), and others have shown that these devices do not effectively destroy microbes, remove odor sources, or reduce indoor pollutants enough to provide any health benefits.
This course attempts to address the common vendor claims and myths associated with use of ozone in indoor spaces.
Course Content
This course content is in the following PDF document:
Overview of Refrigerants Selection
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Course Summary
The criteria for choice of refrigerant can be summarized as follows:
- Environmental Issue, Ozone Depletion – addressed by the Montreal Protocol and this is factor driving the move from R22.
- Environmental Issue, Global Warming – by far the largest component of TEWI (Total Equivalent Warming Index) is the indirect CO2 emissions from power generation, making the refrigerant direct GWP insignificant.
- Cost - the refrigerant cost together with the system applied costs.
- Efficiency – this can be expressed in terms of running cost and is linked closely to global warming, but very much secondary to the chlorine-free legislation-driven move away from R22.
- Pressure level – component availability and ability to use existing system designs – There is also a cost associated with implementing new designs and cost variances associated with component sizes which may be smaller for higher pressure systems, and so this criterion is closely linked to cost.
- Safety – Includes the investment cost associated with special installation and maintenance requirements for system safety.
- Standards and Building Codes – This may be linked to the safety criterion.
- Availability of compressors and other components.
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
