Types of refrigerants control pdf

When recovering hydrocarbon refrigerants, do not fill the recovery cylinders with more than 45% of the hfc safe fill weight. A refrigerant is a substance, usually a fluid chemical compounds, that is used in a refrigeration cycle to cool a space. Natural refrigerants occur naturally, meaning they are not manmade like other refrigerants that were just discussed. In refrigerating systems, such as air conditioners, the fluid that absorbs and releases the heat is called refrigerant.

Refrigeration systems require operating controls so they can cycle on and off to maintain a certain temperature. In refrigeration and air conditioning applications there are wide range of conditions in which the refrigerants. Refrigerant safety the risks associated with the use of refrigerants in refrigeration and airconditioning equipment can include toxicity, flammability, asphyxiation, and physical hazards. Both options provide temperature control, monitoring, defrost management and alarming for outoftolerance conditions. Risk assessment of refrigeration systems using a2l flammable. Fire hazards of refrigerants in air conditioning control. It is very commonly used in refrigerators, airconditioners and freezers. Working principle under this heading, we have the primary or common refrigerants and the secondary refrigerants. Refrigerants are divided into groups according to their chemical composition. Some automobile manufacturers have already switched over to the new hfo class of refrigerant known as 1234yf. The different types of refrigerants can be grouped as given below ashrae 2008.

European norm standard on the safety of refrigerants. Refrigerant safety significant new alternatives policy. In most cycles it undergoes phase transitions from a liquid to a gas and back again. Following the discovery that some of these chemical compounds may be harmful to the environment, they are being replaced with more environmentally friendly alternatives see figure 5. It is responsible for capturing heat and then releasing it to another space by using the thermodynamic phenomena of phase changes wherein fluid changes into gas. Fire hazards of refrigerants in air conditioning control system. The following is a list of refrigerants with their typeprefix, ashrae designated numbers. The most common refrigerants used for air conditioning over the years include. Fluorocarbons, especially chlorofluorocarbons, became commonplace in the 20th century, but they are being phased out because of their ozone depletion effects.

Massdep has authority to promulgate a regulation under m. Which refrigerants can be used without changing lubricant type dropin. In the last two centuries, human ingenuity made it possible to control. If the switch is working properly, you can turn the switch on and the equipment or device is energized.

Primary refrigerants change states to absorb heat from surrounding areas or substances. Today, the standards for using hydrocarbon refrigerants can be found under the following statutes. Adjusting the knob on this type of control changes only the cut out setting, the cut in. Possible replacements for these refrigerants in commercial applications include ashrae class 2l refrigerants, which have lower global warming potentials but are mildly flammable. Pdf seminar is focused on the fundamentals of vapor compression. Synthetic and organic refrigerants are classified under two main categories, primary and secondary. The rx can support up to 64 case control units for up to 70 types of cases, including deli.

Because lowgwp and natural refrigerants have favorable thermodynamic properties compared to standard synthetic refrigerants, energyefficient systems that also have lowgwp can be designed. Source from the main risk of hydrocarbons is ignition or explosion of the refrigerant. Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or substance. To enable the use of smaller compressors and other equipment the refrigerant should have smaller vapor density. Choice of refrigerants for ship refrigeration systems. Refrigerants are used primarily in refrigeratorsfreezers, air conditioning, and fire suppression systems. Refrigerants are substances, often in liquid form that are used in a refrigeration cycle to cool a certain space. Hazards during the repair and maintenance of refrigeration. Environmental protection agency epa issued regulations under the clean air act to phase out the one of the constant themes throughout the history of the hvac industry is the search for a better refrigerant. May 26, 2016 4 types of refrigerants that are safer than freon erin doman on may 26, 2016 12 comments since determining that the common hydrochlorofluorocarbon refrigerant r22, which has been in use for decades, is not as healthy for the environment as experts once thought, the environmental protection agency has been working to phase out the refrigerant. Refrigerant control devices all expansion device types are suitable for use with hydrocarbonbased refrigerants and component suppliers should be consulted for application and selection. Types nrv and nrvh version 2 ai150286435592en000802 1 nrv and nrvh piston type check valves are designed for installation in commercial refrigerating systems and in residential or industrial air conditioning plants.

Elementary control there are two types of control, openloop and closedloop. The two main types of hazardous refrigerants used in vessel. Refrigerants mix readily with air and, if flammable, may reach flammable concentrations ready to be ignited by an. Types of refrigerants and their environmental impact. Handbook of green building design and construction second edition, 2017. Guidelines for the use of hydrocarbon refrigerants in. Under a lower pressure, the refrigerant liquid absorbs heat. Risk assessment of refrigeration systems using a2l. Knowing the temperature difference across the coils, the amperage, and the airflow all give the technician vital information. They also require safety controls to stop operation if unsafe conditions occur. A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. Design and selection criteria are the same as those for conventional fluorinated refrigerants.

R12 was the refrigerant back in the 20th century for automobile applications. Without being pressureregulated, primary refrigerants absorb all available heat from perishable goods until theyre frozen solid. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. While there is no perfect refrigerant, the chart shows that hcfc123 r123, hfc152a r152a and hfc32 r32 strike a good balance between odp, gwp and efficiency. Introduction there are two basic hazards associated with refrigerants, namely toxicity and flammability febo, 2003b. Pdf refrigerant types, issues, trends and future options. Do not mix flammable refrigerants with other types of refrigerant in a recovery cylinder.

Appropriate control of cold and recooling water side. Under a lower pressure, the refrigerant liquid absorbs heat and changes to a vapor. Research and development roadmap for nextgeneration low global warming potential refrigerants introduction 9 1 introduction 1. The closed circuit ensures repeated use of the same refrigerant with little or no loss to atmosphere. A4aodn, a4aoedn, a4aosdn and a4aoesdn port size 20 100 mm 34 4 for ammonia, r12, r22, r502 other refrigerants and oil features pilot operated characterized modulating plug precise control suitable for all common refrigerants and oil 28 bar 406 psig design pressure ps flanges for threaded or welded.

Another fan located inside the home blows air over the cool coils to distribute the resulting cold air throughout the building. Examples of secondary refrigerants include water, air, hydrocarbons, ammonia and carbon dioxide, which are more environmentally benign than traditional refrigerants such as hcfcs. What is refrigerant and how does it help your air conditioner. Automatic controls for industrial refrigeration systems. A comparison between refrigerants used in air conditioning. They are used to control the unidirectional flow of refrigerant so as to prevent backflow. The following is a list of refrigerants with their typeprefix, ashrae designated numbers, iupac chemical name, molecular formula, cas registry number blend name, atmospheric lifetime in years, semiempirical ozone depletion potential, net global warming potential over a 100year time horizon, occupational exposure limitpermissible exposure. Mike opitz, certification manager, leed for existing buildings usgbc says, chemical refrigerants are the heart of a large majority of building hvac and refrigeration equipment. Capillary tube length is specific to each refrigerant. The most common types of refrigerants in use nowadays are presented below. Newer hfc blends and hfo blends are compatible with poe oil, so there is no need to change oil types if retrofitting from an hfc such as r404a to r407a, r407c, r448a, or r449a.

If the switch is turned off, the equipment or device is deenergized. The process starts in the evaporator component of the system. R410a is primarily used for home and commercial units made on or after 2010. Environmental management of refrigeration equipment pdf, 151kb. Any substance, which absorbs heat through vaporization or expansion, is called a refrigerant. Properties of refrigerants n low boiling point and high latent heat of vaporization n dense vapor n low toxicity n non flammable n low miscibility with oil. Nearly all of the historically used refrigerants were flammable, toxic, or both. They can be utilized as cooling agents for refrigerators and air conditioners. Refrigerants and the refrigeration system determine the pressures. Refrigerant control devices all expansion device types are suitable for use with hydrocarbonbased refrigerants and. The four types of refrigeration systems you need to know. However, the new generation of environmentally acceptable. As the name suggests, these types of systems transfer heat by mechanically compressing refrigerant into a lowpressure, cold liquid and.

Types of refrigerants and their environmental impact gineersnow. History modern refrigeration methods, as distinguished from the use of ice and snow, go back to the early part of the 19th century. The first generation of refrigerants included substances such as hydrocarbons, ammonia, and carbon dioxide. Examples of natural refrigerants are hydrocarbons, ammonia, carbon dioxide and water. A comparison between refrigerants used in air conditioning derya ozkan, ozden agra and ozlem cetin university of yildiz technical university, turkey corresponding email. Refrigerants are used in a variety of applications including chillers, refrigerators and freezers, and air conditioners. However, the use of r152a and r32 is limited because of flammability. Although refrigerants can pose one or more of these risks, system design, engineering controls, and other techniques mitigate this risk for the use of refrigerant in various types of equipment. The process is not easy, and although there are alternatives to old refrigerants.

Comparison of environmental impacts and physical properties of refrigerants ko matsunaga executive summary even before the invention of refrigeration, people wanted to improve their life by using ice to provide cold drinks and preserve food. Penn state has developed a refrigerant management program to address the proper handling of these materials. Mechanical refrigeration makes possible the control of the pressure and therefore, the temperature at which a refrigerant boils within the limits of critical pressure and temperature. In the hvac industry, refrigerants are used in various equipment such as air conditioners, refrigerators, freezers, etc. Refrigeration system choice of refrigerants for ship refrigeration systems choice of refrigerant. Many working fluids have been used for such purposes. Refrigerants can be broadly classified based on the following.

The rxs flexible control options allow retailers to choose between standard refrigeration control and distributed case control. Lesson 1 covers a basic understanding of refrigerants, including the history of refrigerants, terminology, and refrigerants types such as cfc, hcfc, hfc, natural refrigerants, and blends zeotrope and azeotrope. Secondary refrigerants allow the amounts of environmentally harmful primary refrigerants to be minimized and contained in a restricted area. This program applies to all refrigerants, refrigeration. The following dates and events illustrate the development of the industry and the variety. Evacuate the recovery cylinder to remove air before filling it with flammable refrigerant. It was soon evident, though, that the lack of chlorine and that the new ester oils did not have the same good lubrication properties as mineral oil and cfc refrigerants. In many instances, the driving factors for alternative refrigeration system decisions are marketing exposure and demonstrating good environmental stewardship. Hfc refrigerants are not miscible with the mineral oils used in cfc refrigeration systems. The primary refrigerants are those that pass through the processes of compression, cooling or condensation, expansion and evaporation or warming up during cyclic processes. Without being pressureregulated, primary refrigerants absorb all available heat. The refrigerant is the fluid that is used in the vapor compression refrigeration system for carrying the heat from the substance or the fluid to be cooled and throws it to the atmosphere. The flood of the airconditioner, that is, the refrigerants, their properties, merits and demerits are summarized to map the various types and their classifications.

Learn the types of refrigerants bright hub engineering. Guidelines for the use of hydrocarbon refrigerants in static refrigeration and air conditioning systems. When liquid refrigerant escapes into the atmosphere it boils at extremely cold temperatures. There are suitable alternative refrigerants on the market today to replace many of the traditional refrigerants which are in common use and, in some cases, are the only alternatives. This article has been excerpted from a comprehensive white paper, refrigerants for commercial refrigeration applications, issued by copeland corp. Automatic controls for industrial refrigeration systems danfoss. There are many kinds of refrigerant and or refrigerant on the market today, but only a few that are widely used. The first type of blends incorporate the following refrigerants. In broader sense, the term is also applied to such cooling systems as cold water or brine solutions. Technical risks associated with leak detection and repair are expected to be relatively small. Properties of refrigerants n low boiling point and high latent heat of vaporization n dense vapor n low toxicity n non flammable n low miscibility with oil n low cost ammonia n has good heat transfer properties n not miscible with oil n but n toxic n flammable n corrosive to. Hazards during the repair and maintenance of refrigeration systems on vessels the repair and maintenance of refrigeration systems can present hazards to both workers servicing these systems and those in the general area. Natural refrigerants was developed as a joint effort between the.

The process is not easy, and although there are alternatives to old refrigerants, the new ones are usually not flawless. Refrigerant management environmental health and safety. What are the most common types of refrigerant today. If improperly vented to the atmosphere, these gases can cause harm to the environment.

While older refrigerant type air dryers have used cfc refrigerants such as r12 and r22, newer designs are in compliance with the montreal protocol and use chlorine free refrigerants such as r4a and r407c or other environmentally friendly refrigerant blends. In the last two centuries, human ingenuity made it possible to control fully. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital. Hence, new synthetic ester lubricants were developed for this application. Dupont formacel z4 reading a pdf file on nook color foam expansion. The refrigerant then cools down and turns back into a lowpressure gas. Openloop control consists of a switch connected to a piece of equipment. Guidelines for the use of hydrocarbon refrigerants in static. The article focuses on the criteria for refrigerant selection, including discussion of the transitional refrigerants hcfcs, chlorinefree refrigerants hfcs, and halogenfree refrigerants. It was banned in 1994 due to it harming the ozone layer. The capacity of refrigerant control devices expansion. This article is the brief overview of what are refrigerants and the history of refrigerants. The primary refrigerants used in commercial reachin and walkin coolers are r404a and r4a, greenhouse gases with global warming potentials gwps in excess of 1,400. A refrigerant is a compound that goes under a phase change from a gas and liquid and then back.