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Into Thin Air: A Guide to the Causes and Signs of Freon Leak

September 6, 2023
Into Thin Air A Guide to the Causes and Signs of Freon Leak

ACs have become an essential component of almost all homes, saving us from the scorching heat of the summer. But as much as these units can give us comfort, they can also be the source of some of our worries.

Let’s talk about something that’s been chilling—quite literally—right under our noses: freon leaks. Yes, those hush-hush escapes of refrigerant that can turn our cool living rooms into something a lot less refreshing.

We’ll dive into the causes of these leaks, the signs to watch out for, their possible effects on the body, and ways you can prevent it from happening. So, get your notepads and take down notes as we tackle this leak.

What is Freon?

What is Freon

Freon is a brand of halocarbon products used as refrigerants for air conditioners and propellants in products like spray cans. 

Due to the brand’s popularity, it’s now used by many as a general term for all refrigerants, including those of other brands.

Freon, like other refrigerants, absorbs heat from indoors and releases it outdoors, creating a colder environment indoors. Basically, your AC can’t cool your home without it.

What can cause a Freon leak?


Over time, the metal components of the AC, such as pipes, fittings, and joints, can corrode or erode. This can lead to tiny holes where Freon or other refrigerants can leak.


Some AC components, like compressors and fans, will naturally vibrate as they operate. These vibrations can lead to wear and tear on the system’s pipes, fitting, and connections, leading to narrow openings where Freon can leak.

Faulty Installation

One common cause of Freon leaks is faulty installation. When the fittings are not tightened properly or the sealing material used is of poor quality, they won’t be able to handle the AC’s operation, and Freon may start leaking.

Factory Defects

Sometimes, it’s not really a faulty installation but a factory defect that’s causing the leak. No matter how much you tighten the fittings and how good the sealing material is, a leak will eventually happen if some components of the AC are faulty.

These issues can usually be detected during installation, but there are still instances when the technician doesn’t notice them.

Formic Acid

Formic acid is a naturally occurring compound that can damage certain components of your AC. Leaks caused by formic acid can be a huge problem, as they usually happen in multiple areas.

Formic acid can come from various sources, including the oils and lubricants used in your AC.

Inadequate Maintenance

Lack of regular maintenance can contribute to the development of Freon leaks. Without proper care, issues such as corrosion, wear, and deterioration might go unnoticed and worsen over time.

Dirty coils and filters can reduce the AC’s efficiency and cause it to work much harder than it should. This can lead to excessive vibrations, freezing, and corrosion, which can all cause Freon leaks.

What are the signs of a Freon leak?

Inadequate Cooling

One of the most noticeable signs of a Freon leak is a decrease in the cooling or refrigeration performance of the AC unit.

If there’s a Freon leak, the refrigerant gradually escapes the system, reducing the amount available for heat transfer. This means the system becomes less effective at absorbing and releasing heat outside, leading to inadequate cooling.

A refrigerant leak can also lead to changes in pressure and temperature within the system. These changes can cause components to malfunction and further impact the cooling efficiency.

Higher Electricity Bills

A Freon leak can reduce system efficiency, causing the system to work harder and consume more energy. The system may also need to run for longer periods to maintain the desired temperature, driving up electricity usage and costs.

Moreover, ACs with a Freon leak can’t regulate temperature effectively, which may result in fluctuations where the AC alternates between running and stopping. These frequent start-stop cycles further increase energy consumption.

Hissing Sounds

If you hear hissing sounds coming from your AC unit, it’s probably a sign that Freon is leaking from it. The size and intensity of the hissing sound can vary depending on the size of the leak and the amount of Freon escaping it.

When there’s a leak in the system and refrigerant starts escaping, the pressurized gas moves from an area of higher pressure to an area of lower pressure. This movement through a small opening or leak point can create a hissing sound.

Frost Buildup around the Evaporator Coil and Refrigerant Line

Some may think that frost buildup in the evaporator coil and the refrigerant line is normal since the AC is often cold, but that’s not true at all! A frost buildup can be caused by an issue in the AC, like a Freon leak.

When there’s a Freon leak in the system, the amount of refrigerant available for the evaporator coil’s heat absorption can be reduced. This can disrupt the normal heat exchange process in the system.

This disruption can cause the coil to become too cold, leading to the formation of ice or frost on its surface.

Odd Odor around the House

Leaking refrigerant can emit chemical odors that are unusual and unpleasant. If you notice strange or strong odors around your AC unit, it might be a cause for concern.

Freon can emit a sweet, chemical odor that’s quite similar to that of acetone. There are also some instances when the room smells oddly fruity because of the leak.

The scent can vary depending on the type of refrigerant the AC is using. Some may also not have a distinct odor, making it harder to detect a leak. 

Increased Humidity

If you notice an increase in the room’s humidity, it can be an indicator that the AC is not functioning properly and Freon is leaking.

Warm air usually holds more moisture than cold air, so when the AC absorbs warm air from the room and transforms it into cold air, it’s also essentially removing moisture from the air. 

If there’s not enough Freon, the AC won’t be able to absorb as much warm air, leading to increased humidity.

Warm Air from AC

As we’ve said before, the AC’s ability to absorb and cool down air depends on the amount of refrigerant or Freon it has. When the AC stops producing cold air, the amount of Freon it has is likely low.

With insufficient Freon, the AC won’t be able to effectively cool the air it absorbs. This can result in warm or room-temperature air coming out of the system rather than chilled air.

Non-Stop Running of the AC

When Freon leaks, it compromises the AC’s cooling ability, forcing it to continuously run to make up for the lack of refrigerant. This is the only way the AC will achieve the set temperature.

If you notice that the AC is unusually running longer or just doesn’t stop running at all, then it’s time to check the refrigerant level.

How do you fix a Freon leak?

How do you fix a Freon leak

Only professional HVAC technicians with the necessary knowledge, experience, and equipment should attempt to repair a Freon leak. Repairing a Freon leak without proper training or experience can be dangerous.

Some may try to fix some damage in the pipes by using regular sealants, and while this may work, it’s only temporary and may lead to more significant problems.

Moreover, you’ll have to replace the Freon or refrigerant that leaked, which can be dangerous if you don’t have proper experience.

How much does it cost to repair a Freon leak?

How much does it cost to repair a Freon leak

An AC Freon leak can be costly to repair, costing anywhere between $200 and $1,500. The final cost depends on the severity of the leak, the price of the refrigerant to be used to refill it, and the replacement parts that may be used.

How to prevent Freon leak?

Although it is impossible to totally prevent the risk of a Freon leak, there are a number of measures that may be taken to significantly reduce the likelihood of a leak occurring and lessen its damage should one occur. 

Hire a professional to install the AC

Hire a professional to install the AC

One of the primary causes of Freon leaks is poor installation of the AC unit. Hiring a professional HVAC technician ensures that your AC is installed using the components compatible with the system and refrigerant used.

Professional installation also ensures an airtight connection between the components and refrigerant lines, minimizing the risk of Freon leak.

Perform regular inspections on the AC

Perform regular inspections on the AC

Conduct a visual inspection of the refrigerant pipes, fittings, connectors, and other AC components regularly to make sure there’s no sign of corrosion, wear, tear, or damage. Doing this can help you identify issues that can become a big problem.

Do routine maintenance on the AC

Do routine maintenance on the AC

Whenever you perform regular inspections, you’ll recognize all the faulty parts and things that should be done to the AC. It’s crucial you don’t put off addressing these issues to prevent the Freon from leaking.

Regularly clean the AC components, remove any debris or dust you see, and provide necessary lubrication to the compressor. It’s best to hire a professional HVAC technician to do these to avoid causing problems to the unit.

Maintain the correct refrigerant levels in the AC

Maintain the correct refrigerant levels in the AC

When the refrigerant levels of the AC are maintained correctly, the AC will work efficiently, minimizing stress on different parts of the unit. In turn, this also reduces the risk of wear or damage that can cause a Freon leak.

It’s important that you hire a professional HVAC technician to check your refrigerant levels and refill it. Freon and other refrigerants can pose health issues, so it’s highly discouraged for non-professionals to handle them.

Is Freon leak dangerous?

Is Freon leak dangerous

Freon is a toxic substance, so it can be dangerous when it leaks. Inhaling high amounts of Freon is harmful to humans and may cause several health issues like refrigerant poisoning.

That said, it’s important to note that refrigerant poisoning is rare and only happens when you’re exposed to refrigerants for a long time. You’ll likely feel mild symptoms, but they’re generally not life-threatening.

Keeping the home well-ventilated can also help avoid refrigerant poisoning.

What are the symptoms of refrigerant poisoning?

What are the symptoms of refrigerant poisoning

Symptoms of refrigerant poisoning vary greatly depending on the severity of exposure to refrigerant. The more Freon you inhale, the more severe the symptoms will be.

Mild to moderate poisoning can happen if you’re exposed to a refrigerant leak in an enclosed space or directly inhale Freon while checking the AC. Some symptoms include

  • Dizziness
  • Headaches
  • Nausea
  • Coughing
  • Vomiting
  • Irritation in the eyes, nose, and throat

If you were exposed to Freon and other refrigerants for an extended period, the symptoms may be more severe, and you’ll likely need medical help. Some symptoms of severe refrigerant poisoning include

  • Chest pain
  • Breathing difficulties
  • Irritation to the lungs
  • Fluid buildup in the lungs
  • Vomiting blood
  • Seizure
  • Loss of consciousness
  • Confusion or disorientation

Does Freon still leak even when the AC is off?

Does Freon still leak even when the AC is off

Freon and other refrigerants can continue to leak from an AC system even when it is turned off. This is because the presence of Freon in the AC is not dependent on whether the unit is actively running or not.

The refrigerant may leak faster when the AC is running, depending on the location of the leak, but turning it off won’t completely stop the leak. The only way to stop the leak from happening is by sealing off the area where the Freon is escaping from. 

Why do modern ACs not use Freon anymore?

Why do modern ACs not use Freon anymore

Modern ACs are moving away from using Freon refrigerants because of their harmful effects on the environment. Freon and other CFCs are among the biggest contributors to ozone depletion.

Among the goals of The Montreal Protocol, an international treaty established to protect the ozone layer, was to phase out the production and consumption of ozone-depleting substances, including CFCs.

This led many countries to implement regulations that restrict or ban the use of CFC-based refrigerants like Freon. 

As a result, several manufacturers have started using refrigerants that are more environmentally friendly, like hydrofluorocarbons (HFC) and hydrofluoro-olefins (HFO).

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