So, your air conditioning (AC) blows hotter air than a politician hoping for re-election. Damn! Rolling down the windows only goes so far, and sitting in a stagnant olfactory puddle of thigh sweat and oil-rich exhaust fumes is a recipe for an uncomfortable and nauseating ride.
Contrary to popular belief that air conditioning blows icy air into the cabin, an air conditioner creates the feeling of cool air by making the hot airless hot. It extracts heat instead of adding cold. This is achieved with a circulation system that includes both a compressor and a condenser and relies on a refrigerant that absorbs heat. The most common reason an air conditioner gets warm is a low level of this refrigerant.
Luckily, this is also the easiest to fix. To get you feeling icy and cool again in the summer heat, The Drive information team is here to show you exactly what you need, what to do, and how to do it.
How Does AC Work in a Car?
The air-conditioning system in a car works by manipulating refrigerant between a liquid and a gaseous state. As the refrigerant changes states, it absorbs heat and humidity from the vehicle and allows the system to give off cool, dry air.
To change the refrigerant between a liquid and a gaseous state, the air-conditioning system works to control pressure and temperature.
How Do You Know When Your Car’s Air Conditioning Needs to Be Charged?
In the event that your car’s air conditioning develops a leak, there are a few telltale signs it could benefit from a boost or need repairs:
- The air conditioner is blowing warm air: The first and easiest way to tell if your car’s air conditioning needs to be charged is if it is blowing warm air out of the interior vents. Since the system works by circulating the pressurized refrigerant, less refrigerant will affect its performance.
- The A/C clutch will not engage: When your car’s A/C is fully operational, you will occasionally hear a slight “click” as the A/C clutch engages. However, if you don’t hear the click (from outside the vehicle), it’s probably because the system isn’t working properly and the refrigerant level is low.
- Visible Leaks: Another easy way to tell if your car’s air conditioning needs to be charged or repaired is when you notice thin, greasy puddles on the floor under your car’s engine bay. If the refrigerant is leaking that badly, it is imperative that you have it serviced.
Now follow these steps to learn how to charge the car air conditioner.
Here’s How to charge Auto AC
Anyone who can follow the instructions can charge the car air conditioner. Get your goggles and gloves, grab the refrigerant and fixing hose and let’s get cold!
- Turn on the car, make sure it is in park and set the parking brake.
- Turn the air conditioning down to the coldest setting, turn the fan up to the highest setting and push the button to circulate the air.
- Open the hood, locate the AC low pressure service port between the compressor and evaporator and remove the plastic cap. If you can’t find the service port, A/C Pro offers a handy online port finder. A secondary method is to use the fitting from the refrigerant hose as it only fits onto the low-pressure fitting.
- If the attachment hose is disconnected from the refrigerant can, connect the hose to the low-pressure point.
- With the compressor on, look at the supplied gauge and turn the temperature dial to the current temperature.
- If the pressure is in the red area of the pressure gauge, do not top up. This is a sign of a larger problem, possibly a faulty or non-working compressor.
- If the PSI reading is lower than the labeled “full” range on the gauge, more refrigerant is needed.
- Disconnect the hose from the service port.
- Remove the safety tab from the refrigerant can, shake the can and reattach the gauge and hose to the can.
- Connect the hose to the low-pressure service port and use the trigger to begin charging the system with refrigerant. Twist the can up and down to maintain good refrigerant flow.
- Use the built-in indicator to determine when the system is full. Don’t overload.
- Remove the plug from the outlet and recycle all empty cans in accordance with local recycling laws.
How Often to Recharge Your Car Air Conditioner?
Recharging the AC on a car is not a regular maintenance item on your car’s manufacturer-recommended maintenance schedule. In theory, the system is sealed, and you should never need to do this.
In practice, however, rubber seals dry up and wear out, and refrigerant slowly evaporates over time, leaving too little in the system for the air conditioner to work effectively. Other components can fail as well, but attempting a recharge is the first thing you should try, particularly since this is a cheap and easy DIY fix and often all it needs to start working again.
How Much Does It Cost to Recharge Car AC?
The Average Cost to Recharge Your Car Air Conditioner Is $20 to $155, Depending on if You Go to the Mechanic or DIY.
- Cost at the Mechanic: $123 to $155
- Cost to DIY: $20 to $50
This cost is generally not that high when you consider that this maintenance will also extend the life of your compressor and keep your air conditioner running at its best season after season.
The average cost of professional AC charging ranges from $150 to $300 depending on the make and model of your vehicle. Due to refrigerant losses that occur over time, this service should be added to your vehicle maintenance schedule. It is recommended that this service be performed on a vehicle approximately every 100,000 miles.
You can save on these costs by going the DIY route and charging your car’s air conditioner. In that case, you can expect to pay $40-$60 for a proper charging kit. This might seem like real savings when taking the car to the shop, and possibly more convenient, but before proceeding with the do-it-yourself alternative it’s important to understand exactly what happens when you get AC service in a workshop instead of doing the work yourself.
What Happens If You Overcharge Your AC?
If you perform this service yourself, you will have the correct refill kit to guide you in adding the correct amount of refrigerant to your vehicle’s air conditioning system. However, it is possible for too much refrigerant to be pumped, causing the air conditioner to “overcharge”.
The result is that your compressor is unable to provide the proper cooling capacity and warm air is instead delivered into your vehicle. So, it is best to be very cautious when assuming that a non-working air conditioner is low on refrigerant, as this is not always the case.
If you are overcharging the system, it is best to take the vehicle to a mechanic to have the system properly drained by an air conditioning machine and thus wait for the correct amount.