Updated On

May 1, 2024

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    Air conditioners are closed-loop, sealed systems. Under normal operation and proper installation conditions, your AC unit should never lose refrigerant. So, you should never need to add more to it. That said, if you have a refrigerant leak, you will need to hire an HVAC contractor to fix it and recharge the system to proper refrigerant levels.

    Refrigerant is essential in all central air conditioners. If your air conditioner’s refrigerant levels are too low, it can damage components like the compressor, condenser, and evaporator coil. With so many costly parts at stake, how do you know when your AC needs more coolant? Keep reading to find out.

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    What Is Refrigerant Used For In Your Air Conditioner?

    Without refrigerant, your air conditioner is little more than a central fan. Your AC unit uses refrigerant to remove heat from the warm air in your home and expel it outdoors. Low refrigerant levels could be a reason why your AC constantly runs. If there is little to no refrigerant left in the system, it won’t be able to remove heat. In this case, the blower would still push air out your vents, but it won’t be cold.

    How Do You Know What Type Of Refrigerant Your Air Conditioner Needs?

    You can determine what refrigerant your AC unit needs by looking at the plate of the indoor unit. You can also check the refrigerant valves on your outdoor unit – both will indicate what type of refrigerant it takes.

    If you have a newer air conditioner, it likely doesn’t use freon. The Environmental Protection Agency (EPA) and other global environmental agencies completed a phaseout of R-22 refrigerant (also known as freon) that began more than 10 years ago.

    Units manufactured after 2010 use a more affordable, less harmful new refrigerant like R-410A, also known by the brand names Puron®, Forane® 410A, GENETRON AZ-20®, and SUVA 410A®. If you are still unsure what type of coolant your system uses, consult your owner’s manual, contact the manufacturer, or hire an HVAC technician. 

    How Do You Know If Your HVAC Unit Freon Levels Are Low? 

    There are many signs that it’s time for a refrigerant charge. Most of the time, if you think your AC system would benefit from recharging, you are correct. 

    As a homeowner, you know if your air conditioner is running longer, struggling to lower the temperature you set on the thermostat, and making noises it didn’t make in the past. And, if you find yourself asking, ‘is my home AC blowing warm air,’ you might need your system recharged.

    An easy way to check is to turn your air conditioner on and set the temperature 10 degrees lower than the room temperature. After the air conditioner runs for 30 minutes, check the refrigerant lines that connect your condenser to your indoor air conditioning unit. 

    If you see ice on the copper pipes, you will likely need more coolant. A frozen evaporator coil is also a sign that the amount of refrigerant in your unit is too low. Icing can also be a symptom of a refrigerant leak.

    Homeowners can’t legally access or recharge refrigerant in their AC units. In fact, there are strict EPA requirements and certifications to do so. As such, it is best to consult with an HVAC company — they can check your levels with refrigerant pressure gauges, identify leaks, seal them, and recharge your system.

    For information on how to check refrigerant levels using pressure gauges, check out this video:

    How Frequently Should You Add Freon To Your AC Units?

    If they are properly installed in the first place, HVACs are sealed systems. So, once an EPA-certified HVAC technician recharges your AC, you should never have to worry about low refrigerant levels unless you have a refrigerant leak or replace a component that uses it. If you think your AC is low on coolant, you should schedule a service call with a professional HVAC technician.

    Freon is a toxic chemical that can be harmful if ingested by pets or children. It can also be hazardous if you breathe the gas, as it can cut off oxygen to major organs like your brain, heart, and lungs. If there is a freon leak in your house, you may experience symptoms like dizziness, loss of coordination, and shortness of breath. Freon and other refrigerants are also harmful to the environment and the ozone layer.

    What Causes an AC Unit to Lose Refrigerant?

    The main cause of an air conditioning unit losing refrigerant is leaks in the evaporator coils, refrigerant lines, and condenser coils. Leaks can happen from normal wear and tear but are often caused by accidental impacts, too.

    Another cause of leaks is improper installation — most commonly, the HVAC contractor either didn’t seal the refrigerant lines properly or jostled them after installation, leading to a crack. Leaks in refrigerant lines are more common and inexpensive to repair. On the other hand, leaks in the evaporator or condenser coils can easily cost over $1,000 to repair or replace.

    How Much Will It Cost To Recharge Your Air Conditioner Unit? 

    The cost of refilling your AC unit depends on your system’s size and the type of refrigerant your system uses. If you have an older HVAC system, refilling it will likely be more costly. 

    Due to the EPA’s new guidelines, there is a ban on the manufacturing and importing of R-22 freon. What does that mean if you own an older HVAC system?

    It means you can expect to pay double or triple what a homeowner with a new system pays to add freon. On average, you can expect to spend as much as $80 to $120 per pound for R-22 refrigerant, whereas the newer R-140A coolant only costs around $20 per pound.

    Now, multiply the price per pound times the number of pounds your central air conditioner needs to determine the cost of refilling your system. You will also need to pay the technician to repair any refrigerant leaks. 

    The average repair bill for refrigerant line leaks is between $225 and $1,000. 

    For more info, read our full guide to home AC recharge costs.

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    Final Advice On How Often You Need To Add Freon To A Central Air Conditioner

    You will never need to add freon or other refrigerant to your AC unit unless it has a leak. In that case, you need to hire an EPA-certified HVAC contractor to handle the job. Refrigerants are harmful to the environment and destroy the ozone layer, let alone the negative health effects.  

    Frequently Asked Questions

    Can I add Freon to my AC unit myself?

    No, you can’t add Freon or refrigerant to your AC unit yourself, unless you’re an EPA-certified contractor.

    How much does it cost to recharge an AC unit with refrigerant?

    Recharging your AC unit with refrigerant costs between $200 to $600 on average. If your system has a leak, you will have to pay additional repair charges, too.

    How do I know if my AC unit needs more refrigerant (Freon)?

    Your air conditioner may need more refrigerant if it is blowing warm air, making abnormal hissing or bubbling noises, or has ice forming on evaporator, condenser, or refrigerant lines.

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    Reviewed for accuracy, cost data, industry best practices, and expert advice by Jonathon Jachura.
    Editorial Contributors
    avatar for Alexis Bennett

    Alexis Bennett


    Alexis is a freelance writer with nearly a decade of experience covering the home services industry. She’s built considerable expertise in roofing, plumbing, and HVAC, as well as general construction and real estate matters. In her free time, Alexis enjoys coaching women’s golf. She lives in the Triad area of North Carolina.

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    photo of Jonathon Jachura

    Jonathon Jachura


    Jonathon Jachura is a two-time homeowner with hands-on experience with HVAC, gutters, plumbing, lawn care, pest control, and other aspects of owning a home. He is passionate about home maintenance and finding the best services. His main goal is to educate others with crisp, concise descriptions that any homeowner can use. Jon uses his strong technical background to create engaging, easy-to-read, and informative guides. He does most of his home and lawn projects himself but hires professional companies for the “big things.” He knows what goes into finding the best service providers and contractors. Jon studied mechanical engineering at Purdue University in Indiana and worked in the HVAC industry for 12 years. Between his various home improvement projects, he enjoys the outdoors, a good cup of coffee, and spending time with his family.

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