How Long Does It Take For Freon In An AC To Settle?

If you’ve recently moved or have pulled your air conditioner out from storage, you’re probably wondering, how long does it take for freon in an air conditioner to settle and cool down? What if your central AC was just topped off?

In this article, we will determine how long it takes for freon to settle. And why letting freon settle will ensure your home stays cool.

How Long Does It Take For Freon To Settle In An Air Conditioner?

Freon is a refrigerant used in air conditioning systems. A refrigerant is a chemical compound that lets your air conditioner produce cold air.

Your air conditioner produces cold air by heating freon through compression. Hot, gaseous freon is then cooled as it passes through a series of tubes and coils where it converts into a liquid. Cool, liquid freon then funnels into the air conditioner’s evaporators. The liquid freon converts back to a low-pressure gas that cools the air in your home.

Freon takes anywhere from 5 to 30 minutes to settle. Damage to your air conditioning unit can occur if freon is not allowed to settle. When freon doesn’t settle, your air conditioner’s compressor will have to work harder to cool the air in your home. Or, freon can leak into other parts of an air conditioner’s system, causing the unit to fail.

The effect is twofold. Freon will clog delicate machinery inside your air conditioner. And the total amount of freon circulating in the compressor will diminish. Together, these two factors will decrease the cooling abilities of your air conditioner.

Air conditioners should be stored right-side up. When an air conditioner is properly stored, freon takes about 30 minutes to settle. Larger units that use more freon need more settling time, anywhere from one to three hours.

For an air conditioner to work, freon must settle within the unit’s cooling system.

If an air conditioner has been left on its side or back for an extended time, the air conditioning unit should settle for 24 hours. Freon takes 10 to 20 years to dissipate in a sealed AC system, but it can dissipate quicker in the presence of leaks.

If your air conditioning unit leaks, contact a HAVC professional to repair your unit and refill it with freon. Once your AC’s refrigerant is replaced, it will take approximately 30 minutes to kick in.

Refrigerant Charging for AC

Central AC

Wait 24 hours before using a central AC unit that has just been installed. Once 24 hours have elapsed, you should not have to wait for freon to settle again unless the unit is moved. If a central AC unit is moved, wait 24 hours before operation to ensure the freon has settled.

Car AC

Freon used in cars does not need to settle before use. Unlike central and portable ACs, car ACs can be refilled with freon by anyone willing to learn how.

Portable/Window AC

The wait time for freon to settle in a portable air conditioner is a few minutes to 24 hours. This depends on how the unit was stored. When in doubt, allow 24 hours for freon to settle in a portable AC. Doing so will ensure longevity out of your AC unit.

Related Article Can You Recharge A Window AC?

Why Is It Important For The Freon To Settle Before Turning On The AC?

Wait for freon to settle before turning on your air conditioner. Doing so allows your air conditioner to function effectively. Turning on an AC before the freon has settled can disrupt its delicate fluid balances. The disruption in fluid balance will decrease your AC’s cooling abilities, leaving your energy bills high and your house hot.

Keep in mind that, in addition to freon, ACs contain oil. The oil in your AC lubricates the compressor, which pressurizes the freon in your unit. The oil in an AC takes longer to settle than freon, typically 24 hours. If you have waited a few hours before operating your AC and the unit is blowing hot air after a few minutes, let the unit rest in an upright position for 24 hours. The compressor’s oil may need more time to settle.

How To Check If The Freon Is Settled?

Unless you are a HAVC technician, you will not be able to verify if the freon within your unit has settled. Rest assured, freon is a dense chemical, and it will settle within 24 hours in a sealed, functional AC.

Doubtful AC owners can test to see if their unit’s freon has settled by turning on their AC unit and testing the temperature of the air from the vents. However, we do NOT recommend this approach because it may damage the AC’s compressor.

If you do not think the freon in your unit has settled and want official verification, contact a HAVC professional to inspect your unit. Doing so will prevent inadvertent damage from befalling your AC.

Carrier Technician

People Also Ask (FAQ)

How do I know if my AC has enough freon?

An AC with adequate freon levels will blow cool air and won’t inflate your electric bill. Warning signs of low freon include ice on the refrigerant line, higher than average energy bills, and vents blowing hot air. A hissing or bubbling sound from the refrigerant line when the AC is in operation may also occur.

Related Article How To Check Freon in an AC

Can an AC run without freon?

An AC will run without freon, but it will not cool your home. If your AC runs continuously but does not cool your home, contact a HAVC professional.

Can I put freon in my AC myself?

No, you cannot add freon to your home AC system on your own. The good news is that most ACs do not need to be recharged with freon unless there is a problem with your unit. If you suspect there may be a problem with your AC, contact a HAVC professional.

How much does it cost to add freon to a home AC?

It costs $200 to $400 to refill a home AC unit with freon.

How do I fill my AC unit with freon?

You don’t. The Environmental Protection Agency (EPA) has strict guidelines on the handling and use of freon. It is a highly toxic CFC gas. Contact a HAVC professional to fill your home AC unit with freon.


Allow at least 30 minutes for freon to settle in air conditioners that have been properly stored in an upright position. Allow 24 hours for freon to settle in air conditioners that have been stored on their side or back.

Allowing freon to settle before unit operation ensures that your AC unit will cool your home for years to come. And it will lower maintenance costs and repairs.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.