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Charge Your Air Conditioning At Home


The vehicle air conditioning system can seem complex, luckily, recharging the air conditioning system is the easiest repair or maintenance item that you can make on the air conditioning unit. Recharging a car’s air conditioning is when the refrigerant, the chemical that is compressed and cooled to produce cold air, is replaced. 

Even in healthy functioning air conditioners, you will see a gradual loss of the refrigerant over many years, and in time that air conditioning unit just isn’t as effective. The unit will regain its cooling properties with a simple recharge. If your car is rapidly losing refrigerant, you have a leak which needs to be repaired before the refrigerant is replaced. If you have an older vehicle 1995 or older you may not be able to recharge your A/C because the refrigerant used at that time is harmful to the environment and the world no longer produces it. 

On average a trip to the mechanic or an A/C recharge will run you about $200 but these costs could be upwards of $300 for the repair based on what mechanic you choose to go to. In some cases you can find a coupon online for mechanics who specialize in working on vehicle air conditioning for as low as $99. Though it is a simple process, it can eat up a lot of time to perform this maintenance item and check the rest of the system over, so most of that expense is a labor cost. 

You can save yourself a ton of money by recharging the air conditioning unit in your car yourself using our how to guide below. If you are unsure about if your car needs to be recharged check out our section on deciding if your car’s air conditioning needs to be recharged. 

How Does Air Conditioning Work?

 The air conditioning units found in cars don’t differ that greatly from those found in homes and buildings, in fact they have most of the same components with a few variations in how they draw power. Here is a quick anatomy of parts found in a car air conditioning unit:


The compressor is the starting point for the air conditioning system process. The compressor takes a gaseous refrigerant and compresses it into a liquid. The compressor uses power supplied by the engine accessed using the compressor clutch.  The process of compressing a gas results in quite a bit of heat. The liquid is then transported to the condenser where it becomes a gas once more.


After arriving at the condenser then takes the hot gas and cools it quickly using a radiator like system of small coils and air flow to remove the heat. Your car uses a cooling fan paired with the airflow from your moving car to cool the refrigerant rapidly. As it cools, it condenses into a liquid once more. 

Cooling Fans

The cooling fan is responsible for providing extra airflow over the condenser. This is in addition to the air supplied by the moving car however there are times where the vehicle is at a standstill and in these scenarios the air conditioning would not work without the cooling fan. 

Expansion Valve Or Orifice Tubes

The expansion valve transfers the refrigerant from the condenser to the receiver. In the process the refrigerant returns to its natural gaseous state. 

Receiver AKA Drier or Accumulator

The receiver is the final step in the air conditioning system, here the refrigerant is dried or dehydrated. There can be small openings where moisture finds its way in and if that moisture were not being removed the entire system would freeze. It is the job of the receiver to remove that outside moisture contamination. This is the final step before being sent into the evaporator where the coolant is actually exposed to the air,  chilling it before sending it into the cab of the vehicle.  


Refrigerant is the chemical that is compressed and cooled to provide cold air to the cab of the vehicle. The refrigerant, while not a mechanical part, is a crucial component to the air conditioning system of any vehicle. Without it, your vehicle would not be able to put out cold air. 

With time, the refrigerant will slowly “leak” out of your vehicle, but it takes many years. This happens with all cars whether they have what is considered to be an actual refrigerant leak or not. If your mechanic tells you that you have a leak in the air conditioning system this isn’t what they are referring to. A leak will be much more aggressive and will need to be repaired before the car is recharged with refrigerant. 

How Much Does It Cost To Recharge Your A/C At The Mechanic

You’ll typically pay $200 at the mechanic to recharge your air conditioning system. Depending on what mechanic you go to you can see costs of up to $300 for the repair. On the other side of that coin you can find great deals online by using coupons at mechanics who specialize in working on vehicle air conditioning for around $99. Recharging an air conditioning unit in a vehicle is not hard, just about anyone can do it themselves, but it can be time consuming which you will see in our “how to” section below. Most of the expense in recharging an A/C is in labor hours. 

How Long Does It Take For Your Mechanic To Recharge Your A/C

It will take somewhere between 30 minutes and 1 hour for your mechanic to recharge your air conditioning unit with fresh refrigerant. On average the job takes 45 minutes of labor to perform. This is a pretty routine job for an experienced mechanic, but for someone trying to do this job themselves at home it can take a bit longer, upwards of 2 hours to research and perform the task if all needed supplies are present. 

How To Recharge Your Car’s A/C Yourself

You can absolutely recharge the refrigerant found within the air conditioning unit of your car yourself if you do your research and follow the steps carefully. We will discuss how to use a recharge kit as they are the safest and most effective option short of having a mechanic do the job. 

What You’ll Need:

  1. Safety goggles/ glasses and protective gloves
  2. Refrigerant between 12 and 28 ounces depending on your vehicle
  3. Air conditioning dispenser with trigger on low side gauge
  4. A meat thermometer

Safety information: you may want to consider wearing sleeves in addition to your gloves when working with refrigerants. If the refrigerant makes contact with your skin it can cause painful burns as it adjusts to the outside temperature and takes on different forms. You should also wear protective eyewear when doing any work under the hood of your car. 

Step 1: Pop the hood of your vehicle and locate the air conditioning unit. 

Step 2: Start the car and turn your AC on max. This is so that you can thoroughly inspect the air conditioning making sure that the components are functioning properly as well as take a temperature reading before the repair has  been made so you have numbers to compare to. 

Step 3: place the meat thermometer in one of the vents in the car while the air conditioning is continuing to run on full blast at its coldest setting. Record the temperature reading. 

Step 4: Check the compressor to make sure it is engaged. If you are unsure of where the compressor is located in your vehicle, do a google search for the make and model of your car and the placement of the compressor under the hood. The compressor has a clutch attached to it and will have a moving belt attachment that should be moving when the air conditioning system is on. 

Step 5: If the compressor is operating normally then it is likely that you don’t have a severe leak and the cause of your air conditioning blowing warm or warmer than normal is that you are low on refrigerant. Proceed to step 5 which is gauging the pressure of the air conditioning system. If the clutch isn’t engaged, then you likely have a more serious problem on your hands including leaks, malfunctioning compressor or an electrical problem. In some cases you can just be really low on refrigerant. If the clutch isn’t working it is typically because your system isn’t pressurized. This can be caused by any of the issues listed above and we recommend taking your car to a mechanic if this is the case. You can also test the pressure and recharge the refrigerant if you believe the system just needs a refill. 

Step 6: Next you are going to test the pressure of the system using the low pressure service port. There are high and low pressure service ports but your adapter will only fit onto the low pressure port so you really can’t mess this up. With some car models they will be marked with an H or an L on the black or gray cap for easy identification. 

Step 7: Once you have located the low pressure system valve, attach the recharge hose from the kit. Pull back on the lip on the mouth of the hose and it should slide right on the low pressure port. Push down firmly until you hear it click into place. Do not pull the trigger. Using the trigger at this time will let the refrigerant escape into the atmosphere which is both wasteful and bad for the environment. 

Step 8: Restart the vehicle once again turning the air conditioning to its highest setting. 

Step 9: Monitor the gauge as the air conditioning clutch engages. Once the compressor is being supplied with power check the pressure reading coming from the low pressure system valve using the recharge hose you attached. If the pressure is reading under 40 psi then you have confirmed that the system is low on refrigerant and needs a recharge. The reading should measure as close to 40 psi as possible. 

Step 10: Now that you have confirmed you need more refrigerant, attach the can of refrigerant to the recharge hose which should still be attached to the low pressure system valve. Once secured, pull the trigger for 5- 10 seconds and then check the pressure in your system again. If you are still under 40 psi, repeat this step using 5 second intervals until you are at or just under 40 psi. You DO NOT want to over pressurize the system so take your time. 

That is it! You have successfully recharged your air conditioning system. To test the results, place the meat thermometer back into one of your vents and read the temperature after about a minute. A fully charged air conditioning system will blow as cold as 28 degrees fahrenheit. 

Remember if your vehicle is struggling to maintain refrigerant that recharging it is only putting a bandaid on a bigger issue. You likely do have a leak unless it has been 5+ years since your last recharge. Enjoy the cold air,  but be sure to evaluate the overall health of the air conditioning system either yourself (if you know what you are doing) or by going to a trusted mechanic. 

The 3 Signs That Your Air Conditioning Needs A Recharge

  1. Loss of cooling
  2. Visible refrigerant leaks
  3. Clutch fails to engage 

Loss of cooling: so this one is pretty obvious, but a lot of issues in your air conditioning unit can cause a lack of cooling. If your car suddenly stopped producing cool air over a short period of time then something is wrong and a simple need for a recharge isn’t your problem. You may have a leak which once repaired can be fixed with a recharging of refrigerant or you may be having an issue with your compressor, condenser, clutch or any number of components. If your car gradually produced warmer and warmer cool air over years then a recharge should solve your problem. 

Visible refrigerant leaks: Usually you can’t see a leak and it needs to be diagnosed by someone who knows what they are doing, however in some cases you can see the part of your air conditioning system that is leaking. A leak can take place anywhere in the system, but the ones you can see are typically involving the sealing of the hoses. Look for an oily build up around where the hoses connect to the other components. If you find a leak around the hose clamp, you or a mechanic can seal it off pretty easily. Repairs must be made to leaking components or the recharge will be a waste. 

Clutch fails to engage: As we discussed in the anatomy section of the air conditioning, a car uses a clutch to drive engine power to the compressor. When you turn on the cold air in your car you should be able to hear a click as the air conditioning system turns on. This audible click is the sound of the clutch shifting on supplying power. The clutch turns on after the pressure of the system is read by the AC pressure switch. When the pressure drops, which is a symptom of not having enough refrigerant, the AC pressure switch will not engage and the clutch will not be activated. When this happens the AC will stop circulating any refrigerant you may have and the entire system will not operate. 

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