Selling refrigeration equipment?
Have YOUR phone here!
Rent entire site or per product categories.

A complete line of refrigeration equipment to meet YOUR needs!


Refrigerants are fluids that change their state upon the application or removal of heat within a system and, in this act of change, absorb or release heat to or from an area or substance. Many different fluids are used as refrigerants. In recent years, the most common has been air, water, ammonia, sulfur dioxide, carbon dioxide, and methylchloride


Common Refrigerants
Ozone Protection and the Clean Air Act
Refrigerant Safety



Common Refrigerants

Today, there are three specific types of refrigerants used in refrigeration and air-conditioning systems:
  1. Chlorofluorocarbons or CFCs, such as R-11, R-12, and R-114
  2. Hydrochlorofluorocarbons or HCFCs, such as R-22 or R-123
  3. Hydrofluorocarbons or HFCs, such as R-134a. All these refrigerants are "halogenated," which means they contain chlorine, fluorine, bromine, astatine, or iodine.
Refrigerants, such as Dichlorodifluoromethane (R-12), Monochlorodifluoromethane (R-22), and Refrigerant 502 (R-502), are called PRIMARY REFRIGERANTS because each one changes its state upon the application or absorption of heat, and, in this act of change, absorbs and extracts heat from the area or substance.

The primary refrigerant is so termed because it acts directly upon the area or substance, although it may be enclosed within a system. For a primary refrigerant to cool, it must be placed in a closed system in which it can be controlled by the pressure imposed upon it. The refrigerant can then absorb at the temperature ranges desired. If a primary refrigerant were used without being controlled, it would absorb heat from most perishables and freeze them solid.

SECONDARY REFRIGERANTS are substances, such as air, water, or brine. Though hot refrigerants in themselves, they have been cooled by the primary refrigeration system; they pass over and around the areas and substances to be cooled; and they are returned with their heat load to the primary refrigeration system. Secondary refrigerants pay off where the cooling effect must be moved over a long distance and gas-tight lines cost too much.

Refrigerants are classified into groups. The National Refrigeration Safety Code catalogs all refrigerants into three groups:

  • Group I – safest of the refrigerants, such as R-12, R-22, and R-502
  • Group II – toxic and somewhat flammable, such as R-40 (Methyl chloride) and R-764 (Sulfur dioxide)
  • Group III – flammable refrigerants, such as R-170 (Ethane) and R-290 (Propane).
R-12 DICHLORODIFLUOROMETHANE (CC12 F2 ) Dichlorodifluoromethane, commonly referred to as R-12, is colorless and odorless in concentrations of less than 20 percent by volume in air. In higher concentrations, its odor resembles that of carbon tetrachloride. It is nontoxic, non-corrosive, nonflammable, and has a boiling point of -21.7°F (-29°C) at atmospheric pressure.

WARNING - Because of its low-boiling point at atmospheric pressure, it prevents liquid R12 from contacting the eyes because of the possibility of freezing.

One hazard of R-12 as a refrigerant is the health risk should leakage of the vapor come into contact with an open flame of high temperature (about 1022°F) and be decomposed into phosgene gas, which is highly toxic. R-12 has a relatively low latent heat value, and, in smaller refrigerating machines, this is an advantage.

R-12 is a stable compound capable of undergoing the physical changes without decomposition to which it is 6-20.commonly subjected in service.

The cylinder code color for R-12 is white.

R-22 MONOCHLORODIFLUOROME-THANE (CHCIF2 ) Monochlorodifluoromethane, normally called R-22, is a synthetic refrigerant developed for refrigeration systems that need a low-evaporating temperature, which explains its extensive use in household refrigerators and window air conditioners. R-22 is nontoxic, non-corrosive, nonflammable, and has a boiling point of -41°F at atmospheric pressure.

R-22 can be used with reciprocating or centrifugal compressors. Water mixes readily with R-22, so larger amounts of desiccant are needed in the filter-driers to dry the refrigerant.

The cylinder code color for R-22 is green.

R-502 REFRIGERANT (CHCIF2 /CCIF2 CF3 ) R-502 is an azeotropic mixture of 48.8 percent R-22 and 51.2 percent R-115. Azeotropic refrigerants are liquid mixtures of refrigerants that exhibit a constant maximum and minimum boiling point. These mixtures act as a single refrigerant. R-502 is non-corrosive, nonflammable, practically nontoxic, and has a boiling point of -50°F at atmospheric pressure. This refrigerant can only be used with reciprocating compressors. It is most often used in refrigeration applications for commercial frozen food equipment, such as frozen food walk-in refrigerators, frozen food display cases, and frozen food processing plants.

The cylinder color code for R-502 is orchid.

R-134a TETRAFLUOROETHANE (CH2 FCF3 ) R-134a, tetrafluoroethane, is very similar to R-12, the major difference is that R-134a has no harmful influence on the ozone layer of the earth's atmosphere and is a replacement for R-12 applications. Non-corrosive, nonflammable, and nontoxic, it has a boiling point of -15°F at atmospheric pressure. Used for medium-temperature applications, such as air conditioning and commercial refrigeration, this refrigerant is now used in automobile air-conditioners.

The cylinder color code for R-134a is light (sky) blue.

Additional Refrigerants

In addition to the previously mentioned refrigerants, other less common refrigerants are used in a variety of applications.

R-717 Ammonia (NH3 ) Ammonia, R-717, is commonly used in industrial systems. It has a boiling point of -28°F at atmospheric pressure. This property makes it possible to have refrigeration at temperatures considerably below zero without using pressure below atmospheric in the evaporator. Normally it is a colorless gas, is slightly flammable, and, with proper portions of air, it can form an explosive mixture, but accidents are rare.

The cylinder color code for R-717 is silver.

R-125 Pentafluoroethane (CHCF5 ) Pentafluoroethane, R-125, is a blend component used in low- and medium-temperature applications. With a boiling point of -55.3°F at atmospheric pressure, R-125 is nontoxic, nonflammable, and non-corrosive. R-125 is one replacement refrigerant for R-502.

All refrigerants have their own characteristics. It is extremely important to charge a system with the refrigerant specified. Use of an incorrect refrigerant can lead to reduced efficiency, mechanical problems, and dangerous conditions.

Back to Top

Ozone Protection and the Clean Air Act

Several scientific studies conducted in the 1970s showed that chlorine was a leading cause of holes in the ozone. In 1987, 30 countries signed the Montreal Protocol, which mandated the phase out of the production, and eventual use, of all harmful CFCs. In 1990, the most significant piece of legislation affecting the air conditioning and refrigeration industry, the Clean Air Act, was passed. Regulated by the Environmental Protection Agency (EPA), Title VI of the Clean Air Act states fully halogenated refrigerants (CFCs) will be phased out. It also calls for the phase out of HCFCs by the year 2030. Both of these types of refrigerants adversely affect the atmosphere, and as of July 1992, it is illegal to discharge refrigerant to the atmosphere. The production of R-12 was discontinued in December 1995, and the production of R-11, R-113, R-114, and R-115 was discontinued in January 2000.

As a result of the Clean Air Act of 1990, there has been a determined effort by manufacturers to develop alternative refrigerants to replace those to be discontinued. CFCs, R-11, and R-12, primarily used in chillers, residential, and automotive refrigeration, can be substituted with HCFC R-123 and HFC R-134a. Future replacements include HCFC R-124 in place of CFC, R-114, in marine chillers, and HFC R-125, in place of CFC R-502, used in stores and supermarkets

These replacement refrigerants have slightly different chemical and physical properties; thus they cannot just be "dropped" into a system designed to use CFCs. Loss of efficiency and improper operation could be the result. When changing the refrigerant in an existing system, parts of the system specifically designed to operate with a CFC refrigerant may need to be replaced or retrofitted to accommodate the new refrigerant.

Back to Top

Refrigerant Safety

Personal protection

Since R-12, R-22, and R-502 are nontoxic, you will not have to wear a gas mask; however, you must protect your eyes by wearing splash-proof goggles to guard against liquid refrigerant freezing the moisture of your eyes. When liquid R-12, R-22, and R-502 contact the eyes, get the injured person to the medical officer at once. Avoid rubbing or irritating the eyes. Give the following first aid immediately:

  • Drop sterile mineral oil into the eyes and irrigate them.
  • Wash the eyes when irrigation continues with a weak boric acid solution or a sterile salt solution not to exceed 2 percent salt.
Should the refrigerant contact the skin, flush the affected area repeatedly with water. Strip refrigerant-saturated clothing from the body, wash the skin with water, and take the patient immediately to the dispensary. Should a person be overcome in a space which lacks oxygen due to a high concentration of refrigerant, treat the victim as a person who has experienced suffocation; render assistance through artificial respiration.

Handling and Storage of Refrigerant Cylinders

Handling and storage of refrigerant cylinders are similar to handling and storage of any other type of compressed gas cylinders. When handling and storing cylinders, keep the following rules in mind: Open valves slowly; never use any tools except those approved by the manufacturer.

  • Keep the cylinder cap on the cylinder unless the cylinder is in use.
  • When refrigerant is discharged from a cylinder, immediately weigh the cylinder.
  • Record the weight of the refrigerant remaining in the cylinder.
  • Ensure only regulators and pressure gauges designed for the particular refrigerant in the cylinder are used.
  • Do use different refrigerants in the same regulator or gauges.
  • Never drop cylinders or permit them to strike each other violently.
  • Never use a lifting magnet or a sling. A crane may be used when a safe cradle is provided to hold the cylinders.
  • Never use cylinders for any other purpose than to carry refrigerants.
  • Never tamper with safety devices in the cylinder valves.
  • Never force connections that do not fit. Ensure the cylinder valve outlet threads are the same as what is being connected to it.
  • Never attempt to alter or repair cylinders or valves.
  • Cylinders stored in the open must be protected from extremes of weather and direct sunlight. A cylinder should never be exposed to temperature above 120°F.
  • Store full and empty cylinders apart to avoid confusion.
  • Never store cylinders near elevators or gangways.
  • Never store cylinders near highly flammable substances.
  • Never expose cylinders to continuous dampness, salt water, or spray.
Back to Top