The Types of Refrigerant Used in Air Conditioning

  • April 19, 2021
  • By MR COOL

Cooling technology is somewhat of a modern miracle. Air conditioning allows for safe food storage, preserving substances and staying comfortable through the year’s hottest months. It involves a complex scientific process using chemicals called refrigerants. Various refrigerants have different qualities, and chemists have been working to make them safer and more efficient.

Like any chemicals, refrigerants require regulation to promote safety and environmentalism. Some refrigerants are subject to phase out regulations, while others are on the rise as replacements. It’s essential to understand how these chemicals work and which are the best options. Depending on the type of AC system you have and the chemicals it uses, it may be time for an upgrade.

What Is a Refrigerant?

A refrigerant is a unique human-made chemical compound. There are dozens of various refrigerants, each with a slight change in composition. Most have a specific combination of only three or four different elements. Over the years, chemists have adjusted refrigerants to be safer and more environmentally friendly. 

AC refrigerants are necessary for any artificial cooling technology. Every household air conditioning unit, industrial freezer and vehicle cooling system requires one of these chemicals. In simplified terms, a refrigerant absorbs the heat from its surrounding environment, providing a cooling effect for refrigeration or air conditioning. In your air conditioner, the refrigerant is within the coils. 

How Does Refrigerant Work?

Refrigerants play a crucial role in any cooling system cycle. They change from a gaseous to a liquid state and back throughout the cooling process. An air conditioner involves a compressor, condenser and evaporator — the refrigerant travels through these areas, changing from gas to liquid and back again. Here’s a brief description of what happens in each air conditioner component. 

1. In the Compressor 

Refrigerants begin in the air conditioner’s compression chamber, absorbing heat from inside the home. The refrigerant starts in the compression chamber as a low-pressure gas. The compression chamber pushes the molecules together, heating them and increasing the pressure. This transition from low to high pressure keeps the refrigerant molecules moving through the rest of the cycle. 

2. In the Condenser 

The hot, pressurized gas then moves into the condenser. This section faces the outside of your home. A few fans expel the gathered heat, where it releases outside. If you stand beside the outdoor portion of your air conditioner, you can feel it pushing out hot air — this is the heat it’s removing from your home! 

As the fans cool the gas, the molecules condense back into a liquid state. Once it’s removed enough heat, the liquid begins to travel to the next area. As the heated refrigerant moves through the system, a metering device measures how much more cooling is necessary to reach the set temperature. It continues if it detects high remaining heat levels. 

3. In the Evaporator 

The last stage of the cycle is the evaporator. The refrigerant, as a low-pressure liquid in the evaporator, is what cools the home. Fans blow over the refrigerant-containing pipes. The chemical then undergoes an endothermic reaction, which means it absorbs the surrounding heat and evaporates back into a gas. As a result of this heat absorption, the surrounding temperature drops. At that point, the fans blow the chilled air into the house for maximum cooling. The refrigerant, now a low-pressure gas again, restarts the cycle in the compressor.

The refrigerant continues this cycle until the home reaches the desired temperature. Then, the meter shuts off the system until the temperature climbs back up. As complicated as it may sound, this cooling process is quick and efficient. If you’ve felt the relief of walking into an air-conditioned space on a hot, humid day, you know how much temperature difference this process can create. 

Who Regulates Heating, Ventilation and Air Conditioning Refrigerant?

Though refrigerants are ideal for storing food, keeping people comfortable and for many other purposes, some refrigerants have adverse effects. These AC refrigerant types reach the stratosphere and contribute to harmful depletion of the Earth’s ozone layer. As a result, the EPA is phasing out these refrigerants.

What Are Chlorofluorocarbons?

You may recognize chlorofluorocarbons, or CFC refrigerants, by the brand name Freon. Before Freon’s invention, air cooling systems used flammable, toxic refrigerants like sulfur dioxide and ammonia. To resolve this dangerous issue, a team of chemists in the 1920s got to work. Their goal was to create nontoxic, non-flammable HVAC refrigerant types. They developed CFCs and called the new chemical Freon gas. 

Chemical Makeup

The elements carbon, chlorine and fluorine make up CFCs. That’s where they get the long-winded name “chlorofluorocarbons.” Different CFCs have varying numbers of those three elements. Most CFCs are small molecules with only one or two carbon atoms. 

History of Uses 

All CFCs share specific properties — they are non-reactive and have practical heat-absorbing abilities. Because they’re so useful, CFCs quickly became mass-produced worldwide. People have used CFCs as refrigerants for many applications, including food storage and indoor climate control. They’ve also used the chemical for aerosol spray cans, manufacturing foams and cleaning agents. 

Environmental Concerns 

CFCs damage the Earth’s protective ozone layer. To appreciate why this matters, you must understand how the ozone layer works. In essence, ozone molecules surround the globe in the upper atmosphere. There, they absorb some of the sun’s ultraviolet radiation. Protecting our planet’s surface from damaging UV rays is crucial. If every UV ray could reach the Earth’s surface unimpeded, our planet would be inhospitable for life. UV radiation can cause cancer and cataracts in humans. It can also lead to damaging physiological changes in plants and affect the survival rates of other animals. 

So, how does CFC harm the ozone layer? CFC molecules reach the stratosphere decades after their release into the air. There, UV radiation splits them into separate chlorine atoms. Each chlorine atom reacts with a nearby ozone molecule, setting off a damaging chain reaction. Every CFC molecule ever created has the potential to destroy a large chunk of the ozone layer. Because the ozone layer is so vital to life on Earth, governments started phasing out CFCs from production and use. 

What Is the Montreal Protocol?

After scientific research revealed the dangers of CFCs, policymakers began passing legislation to limit CFC production and use. The reaction was international. In 1987, the United Nations came together under the Montreal Protocol. At first, the countries agreed to halve their CFC production and use. Over the years, participating countries strengthened the protocol, mandating a worldwide CFC phaseout. Since 1987, 197 countries have signed the Montreal Protocol, making it the most successful environmental action to date. 

The Montreal Protocol represents a pivotal historical moment. It was the first widespread realization that human activities could impact the environment on a global scale. The Montreal Protocol helped teach humanity a valuable lesson and pave the way for other environmental protections. It also meant that scientists would need to develop new, safer refrigerants to comply with these laws. 

What Are Hydrochlorofluorocarbons?

Hydrochlorofluorocarbons, or HCFCs, are a variation of CFCs. They include hydrogen in addition to the three CFC elements — chlorine, fluorine and carbon. The distinction is critical — HCFCs remain in the atmosphere for shorter amounts of time and have a much smaller ozone-depletion potential. They’re Class II ozone-depleting substances. In essence, HCFCs are a transitional substitute for CFCs. Because they’re less dangerous, they have a longer-term phaseout schedule. 

The R-22 Phaseout

R-22 is the shorthand for chlorodifluoromethane, a form of HCFC. You might also see it abbreviated as “HCFC-22.” It’s next up on the phaseout schedule. National refrigerant laws have banned its production, import and use since 2015, except for continuing needs of existing equipment. As of 2020, the EPA banned all remaining production and import, too. For existing equipment, only recycled or stockpiled R-22 can fulfill continuing needs. Strict guidelines apply to R-22 recycling. By 2030, the production and import of all HCFCs will be subject to a final, total ban. At that point, the EPA will destroy all remaining R-22 in circulation. 

What Are Hydrofluorocarbons?

Hydrofluorocarbons, also called HFC refrigerants, are an alternative to their ozone-depleting relatives. However, they have a high global warming potential, much higher than carbon dioxide. That’s why legislators added the Kigali Amendment to the Montreal Protocol in 2015. The HFC phaseout, which began in 2019, is on track to finish up by 2024 for all developed countries. 

Why Is R-410A Refrigerant Better?

One example of an HFC is R-410A. It’s been a preferred refrigerant since its invention. R-410A is superior to other refrigerants for several reasons. R-410A works at higher pressure than other refrigerants. The compressors can withstand a significant amount of vibration, allowing for a longer lifespan. Not to mention, it emits zero ozone-depleting chemicals. Here are some other reasons R-410A is a preferred refrigerant choice: 

  • It has a non-flammable chemical structure, unlike early refrigerants.
  • It’s non-corrosive, so hardware damage is not a concern.
  • It works with several types of tubing, including copper, brass and steel.
  • It’s nontoxic, so it’s safe to use in populated buildings.

Are There Other Alternatives to Freon?

In the future, other alternatives to Freon may become necessary. Thankfully, the market is home to a few safe, efficient and affordable choices. 


R-134A, or Norflurane, is an excellent alternative option, approved for retrofitting. You don’t need to replace your entire unit to comply with phaseout laws. Instead, you can retrofit your R-410A-using system for Norflurane use. 


If you’re looking for something with thermodynamic properties similar to Freon, R-407C is a popular choice. Because it’s safe and affordable, many manufacturers are creating equipment compatible with the refrigerant.

How Do You Tell Which Refrigerant Your HVAC System Uses?

First things first, you’ll have to determine which kind of refrigerant your HVAC system uses. If you’re still using a refrigerant subject to phase out, you’ll want to think about upgrading your system or replacing your refrigerant soon. 

In most cases, you can find the refrigerant in use on the system’s nameplate, which is usually on your central air conditioner’s outdoor condenser element. You can also check your owner’s manual. Otherwise, you could contact the sales company or manufacturer for the information. All you’ll need is the model number. 

Do I Need to Replace My AC Unit If It Uses Freon?

If your equipment has a manufacture date before 2010, you can continue to have it serviced. However, the phaseout will result in a gradually depleted R-22 supply. Only a handful of companies can accept and recover used refrigerant for further use. It will become increasingly expensive to reclaim or recycle refrigerants subject to phaseout. 

Note that it’s not appropriate to mix different refrigerant types — ask a professional to help you make a refrigerant transition. If you have yet to do so, consider replacing your unit with a newer model. If your air conditioner is in good shape, you can put this off for a while. If you start to notice refrigerant leaks, you might need a new unit anyway. 

Can I Upgrade an AC Unit That Uses Freon?

Though retrofitting is a choice for some units, the process is often expensive and complicated. It also might not be an option at all, depending on your unit’s make and model. In most cases, an upgrade to a brand-new model will be the best course of action. Modern systems are long-lasting and have a smaller carbon footprint, and they’re compatible with safe Freon alternatives. A new air conditioner will help you save on energy costs while posing less harm to the environment. 

If your air conditioner system uses a refrigerant subject to phase out, consider replacing it. You’ll find a newer system has many benefits beyond environmental friendliness — it’ll also help you save money in the long run. To ensure you choose the best option for your needs, work with your HVAC technician. 

Learn How to Become a MRCOOL Reseller or Installer 

Refrigerants are one of the cornerstones of modern living. They allow us to store food for extended periods, operate equipment at safe temperatures and stay comfortable in hot, humid weather. Since Freon’s invention, chemists have worked to make refrigerants safer for everyday use. Today, refrigerants that pose a severe environmental threat are on the decline, and several alternative options are emerging. Users are replacing their air conditioners or retrofitting new refrigerants in their systems. 

Now is an ideal time to join a team of air conditioning resellers or installers. Both of these roles will be in high demand in the years to come, as HVAC replacements grow increasingly necessary. Here at MRCOOL, we manufacture high-quality, efficient and affordable HVAC systems. To learn how you can become a MRCOOL reseller or installer, contact our team today.

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