HCFC Refrigerants. These air conditioner refrigerant is considered partially halogenated as they consists of methane or ethane in combination with chlorine and fluorine.
They are shorter lifespan and are less destructive to the ozone layer compared to CFCs. They are an interim solution to a totally "free from chlorine" refrigerant that are being developed.
Their production are scheduled to be phased out totally in The common ones used are:. R is used extensively in residential, commercial and industrial applications. The schedule of phaseout :. HFC Refrigerants. These air conditioner refrigerant contain no chlorine atom and is not destructive to the ozone layer though they have a slight effect on global warming.
Ra is used in new systems that are specially designed for its use. The common HFCs are:. The Kyoto Protocol puts Ra as one of the 6 greenhouse gases that must be reduced. There is no phaseout date for this refrigerant and it is expected to be highly used in the HVAC industry.
Refrigerant Blends. These air conditioner refrigerant are also known as "azeotropic" and"zeotropic". Their use is increasing as they are environmental friendly. The setback is that the total air conditioning systems production cost is higher. The common refrigerant blends used in the air conditioning industry are:. RA are used as a replacement refrigerant for residential air conditioning applications.
RC are used as R replacement. Daikin, Mitsubishi Electric and many other manufacturers are designing new products that use this refrigerant. For toxicity, the first character of the classification denotes the Class which is either A or B, Class A denotes refrigerants with lower toxicity and Class B with higher toxicity. The subsequent one or two characters denotes its flammability.
There are three classifications and one subclass. Class 1 is for refrigerants that do not propagate a flame when tested as per standard; Class 2 for lower flammability and Class 3 for highly flammable refrigerants. Class 2L is for refrigerant that burn very slowly. See the complete Ashrae Standard 34 that include a list of refrigerants with their safety group and global warming potential here. Recovery, Recycling and Reclaiming of Refrigerants. Greenhouse gases act like an insulating blanket over the earth, trapping heat instead of letting it escape into space.
Even when present in very low atmospheric concentrations, they cause a great deal of damage because they have a very long lifetime before breaking down in the atmosphere. It quantifies the amount of heat a gas traps, and how long the effect lasts depending on the lifetime of the gas. That is, it is over 10, times worse for the climate than carbon dioxide!
Since then, only CFCs recycled from old equipment has been available. HCFCs contain chlorine, fluorine, and carbon just like CFC , but also contain a hydrogen atom which decreases their stability and gives them a shorter lifetime in the atmosphere.
They mostly break down before they reach the ozone. HCFC-R22 also known as Freon 22 and R22 has been the standard for use in residential air conditioners starting in the s, when new houses often came with AC, through the mid s with use decreasing through Production and import of R22 was banned on January 1, , except to service and maintain existing equipment. Production and import of R22 will be decreased gradually to zero by , at which point equipment can only be serviced with recycled or stockpiled HCFC-R You can still recharge your equipment after fixing any leaks!
Unfortunately, not a lot of R22 gets recycled. So as supplies decrease, prices will continue to rise. Currently, R22 is at least 5 times more expensive than more modern and preferred coolants, and even that may seem inexpensive in the future.
Refrigerants 5. Evaporators 7. Condensers 8. Practical advice 9. Troubleshooting Systems Appendix Glossary. Some comments on the refrigerants presented in the table are given below: R32 and R are seldom used as single refrigerants, but only in mixtures with particularly favorable thermodynamic properties.
Rc and Rfa are used almost exclusively in the United States and in a rather experimental way. RA has been developed as an alternative to R for refrigerators and freezers. Ra was the first HFC introduced in refrigeration and air conditioning with great success, because it requires almost no changes in the equipment designed for R Consequently, the manufacturer has two choices: either to accept a substantial reduction in the thermal capacity in a given system, or to increase its dimensions and cost to achieve the same capacity.
For this reason, Ra is used mainly in large systems over kW that can afford the higher costs. RC is, like Ra, thermodynamically similar to R22 and works as a "drop in" refrigerant. However, unlike Ra, which is a pure compound, RC has a glide of 7 K, making it barely usable in small residential household equipment. There are two reasons to justify such a limitation: residential equipment is more subject than other equipment to sudden accidental losses, and it is usually serviced on site.
In the event of a sudden leakage, a 7K glide may result in changes in the proportions of the mixture, because the relative losses of its most volatile components will be disproportionately high. If a standard refill is used, there is no guarantee that the new refrigerant mixture has the same proportions as it had before the leakage.
Due to its high glide, this refrigerant is used only in medium-capacity systems kW , which are usually serviced by skilled personnel.
RA has very attractive thermodynamic properties, higher energy efficiency than R22, no glide and hence no problem with the mixture remaining after charge loss and refill. However, it has an operating pressure almost double that of R22, and therefore requires a redesign of the whole system with larger compressors, expansion valves, etc. RA is used successfully in industrial and commercial refrigeration. RB is less frequently used in low temperature cycles.
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