What is AC Refrigerant?

What is AC Refrigerant?

In our everyday lives, we receive a lot of comfort from our cooling appliances. We live in air-conditioned homes, drive in air-conditioned cars, and work in air-conditioned offices. We keep our food safe and fresh using our refrigerators. On a hot, sunny day, we can sit down for an icy cold drink, courtesy of our ice machines.

What makes these comforts possible for us? Cooling machines all operate with the help of one crucial component: refrigerants.

Refrigerants make it possible for us to experience cool air in the summer and fresh food all year long.

What are Refrigerants?

Refrigerants are compounds that can repeatedly change from a gaseous state to a liquid state and back again. This process is what leads to refrigeration and cooling.

Humans have been artificially cooling and freezing things for a very long time. In 1748, Professor William Cullen first demonstrated an experiment in artificial refrigeration. He created a vacuum over a container of diethyl ether, which allowed it to boil and absorb heat.

The procedure successfully produced cooling and even created some ice, but at that time, the experiment still did not have any applications.

The very first chlorofluorocarbons (CFCs) were synthesized and used as refrigerants in the 1890s. When the first electric refrigerators and air conditioners hit the market, the available refrigerants were highly flammable and dangerous to human health.

In the 1920’s, Charles Franklin Kettering assembled a team in General Motors that would research new and better refrigerants. Led by Thomas Midgely, the team would go on to invent Freon, which was regarded as more stable, non-combustible, and safer than the previous available CFCs.

In the 1930’s General Motors and Dupont created the Kinetic Chemical Company, which would produce Freon. At this time, their product was Freon-12, but as time went by, Freon became a trademark of Dupont that pertained to a whole group of refrigerant compounds.

Freon became a massive success, and it was considered the standard refrigerant in cooling appliances for many decades. People felt safe knowing that it was not flammable or toxic.

Thomas Midgely would often do demonstrations by inhaling Freon and exhaling it out onto a lighted candle, which would promptly put it out. The demonstration was enough to convince not only the American Chemical Society but the rest of the country of the wonders of Freon.

Unbeknownst to many, however, are the hidden dangers of Freon. It wasn’t until the 1980’s that scientists found CFCs’ and HCFCs’ major contribution to ozone layer depletion, which could lead to serious consequences for the environment and human health.

The world knew it had to act fast. By August 1987, the Montreal Protocol was signed, and CFCs and HCFCs were phased out of production worldwide.

Today, modern devices instead use HFCs as refrigerants. Although not as harmful as CFCs, HFCs are still strictly controlled substances due to their possible threat to the environment.

Different types of refrigerant

Throughout the history of refrigerants, different types of refrigerants have been used in homes and establishments all over the world. What are these types of refrigerants and how do they differ from each other?


The first type of Freon, R-12, is a chlorofluorocarbon. CFCs have been linked to the depletion of the ozone layer, leading to their phase-out. R-12 ceased production in 1994.


HCFCs (Hydrochlorofluorocarbons), including R-22, continued to be used for some time even after R-12 was completely phased out. R-22 is what many refer to simply as Freon, even though Freon refers to many compounds. Some older air conditioners today still use R-22, but its production has already been phased out last 2022. This means that those with older air conditioners will only be able to use whatever R-22 stock is left in the country.


Hydrofluorocarbons like R-410A and R-134a are the current replacement for CFCs and HCFCs. If your air conditioner is purchased after 2015, your unit most likely uses R-410A or Puron, which is a chlorine-free refrigerant. The absence of chlorine makes hydrofluorocarbons far safer for the environment. Although HFCs are considered safer, they are still under close watch under the Kyoto Protocol due to their contribution to the greenhouse gas effect.

How do refrigerants work in air conditioners?

Air conditioners work by running refrigerant through the machine’s mechanical components.

The refrigerant enters the compressor as a low-pressure gas. In the compressor, the refrigerant becomes highly pressurized and heated to high temperatures. The refrigerant is then sent to the condenser coil where it becomes a cool high-pressure liquid.

The refrigerant travels to the evaporator coil where it evaporates and cools the indoor coil. The fan then blows the warm indoor air from the home on the evaporator coil, where the refrigerant absorbs heat.

The cool air is then released into the home as the now-heated refrigerant is sent back to the compressor to release the heat outside the home.

The refrigerant then returns to its cool liquid state, and the cycle begins again. This whole cycle repeats over and over again until your home is cooled to your desired temperature.

Do you need to refill your AC’s refrigerant?

Refrigerants are meant to last as long as your air conditioner itself. However, that’s not always the case. Your AC can lose refrigerant through a leak, which can happen for many reasons.

Damage to the unit

If your air conditioner sustains physical damage either through an outside force or loose debris inside the unit, your AC may start leaking refrigerant.

Improper installation

Your AC may leak refrigerant due to installation issues. For instance, overtightening of the flare connections can eventually lead to a leak. Make sure to only hire licensed HVAC professionals to do your air conditioner installation for you.

Metal erosion

Certain chemicals like formic acid can cause micro holes in the metal components inside your AC. These holes cause what many call “champagne leaks” due to the bubbling appearance of the refrigerant leaking through the small holes.

Wear and tear

Using your air conditioner regularly leads to normal wear and tear. Your outside unit is exposed to the elements as well, making it more susceptible to damage. The slow and natural degradation of your appliance can lead to a leak forming and your refrigerant level decreasing over time.

Why do you need to watch out for refrigerant leaks?

Refrigerants are crucial to your air conditioning system. A leak will heavily diminish the effectiveness of your unit and will also end up damaging it in the long run. Making an AC run with no refrigerant can eventually damage its inner components like the compressor.

It’s also important to watch out for leaks because refrigerants are dangerous not only to your health but also to the environment. For instance, if your AC still uses R-22, the exposed CFC from a leak will pose danger to the ozone layer.

Although modern refrigerants are considered safer than their predecessors, they are still dangerous when they come into close contact with humans.

Direct physical contact can lead to skin and eye irritation, while contact with the lungs can lead to headaches, nausea, vomiting, and dizziness. In some extreme cases, direct and constant inhalation can cause fainting and even death.

How to know if your AC has a refrigerant leak

There are some warning signs you can watch out for to tell you if your AC is running low on refrigerant. Although refrigerant loss isn’t the only problem that can cause issues in your AC, knowing what to watch out for can help you fix the issue in time before it turns into something bigger.

Loss of Cooling

Since the refrigerant is responsible for cooling, the first symptom you must look out for is loss of cooling ability. Is your AC blowing warm air? Is it taking longer than expected to cool your home? You may have a refrigerant problem. Try to eliminate other factors first by cleaning your AC and its filter. If the issue persists, have an expert take a look at your AC.

Bubbling and Hissing Sounds

A persistent bubbling and hissing sound coming from the internal components of your AC most likely means there is a leak. The bubbling sound comes from the leaking itself while the hissing noise likely comes from the refrigerant making contact with the inner parts of your air conditioner.

High Energy Bills

An air conditioner with leaking refrigerant will have to work harder to cool your home properly. Even if you use your AC at a set time every day with no change to the usage, you may see a spike in your utility bill due to your AC.

Frost or Ice Buildup

One of the most telling symptoms of a leaking AC is frost or ice forming on the inside of your AC, especially the coils. This means the refrigerant has escaped and is making contact with everything inside your air conditioner.

Leak Tests

If you want to make sure whether your AC is leaking or not, you can perform several kinds of leak tests. Some tests are simple like using soap solution or dye to track small leaks. Some tests may be more complicated but can bring more accurate results. You can test the AC’s pressure, or you can also use an electronic leak detector to check.

What you can do to avoid leaks

The best way to make sure your refrigerant stays in your AC is to avoid leaks in the first place. There are a few ways you can prevent damage from coming to your AC.

Clean up the area around your AC to avoid damage from debris. During colder months, cover the top of your outdoor unit with plywood to prevent falling leaves and other debris from getting into the unit and physically damaging its components. You can also trim the plants around your outdoor unit with a big clearance so that the branches and leaves won’t enter the unit.

You can also keep pets away from your outside unit. Pets can bring physical damage to the unit. Dog urine is also highly corrosive to aluminum and copper. Your AC’s internal parts like coils and evaporator fins are made from aluminum, copper, and steel. Constant exposure to your pet’s urine can eventually destroy your unit, so it’s best to make sure that your outside AC unit can’t be accessed by animals, especially dogs.

The best and easiest way to do this is to conduct regular maintenance. Make sure that your AC is clean and free of dirt and debris. You can hire an HVAC technician to conduct maintenance for you at least once a year.

CPI Plumbing, Heating, and Cooling Services

Do you have any concerns with your air conditioner’s refrigerant? Feel like it’s time for a recharge? Call Skagit County’s trusted plumbing and HVAC experts now!

CPI provides high-quality AC repair, replacement, or maintenance services in Mount Vernon, WA, and surrounding areas.

You can also avail of an HVAC service agreement with us and arrange a maintenance plan that’s right for you and your home.

Call us now at (360) 822-9306.

Our team of experts is ready to help you with all your plumbing and HVAC needs.

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