Is the car not cool enough anymore? Stay calm and recharge your air conditioning unit.
Among the many luxuries offered by modern cars, air conditioning is perhaps the one that makes driving the most comfortable. Gone are the hour-long journeys in a stuffy, boiling car in summer and you can stay cool and comfortable on every little trip to the shops. But what happens when your air conditioner stops blowing cold air and why does it happen? If your air conditioner is blowing hot air or only working intermittently, you may have exhausted the substance that gives your car that magical cold air ability. An AC recharge can bring back cold air when you need it most in hot weather.
WHAT IS AIR CONDITIONING RECHARGE?
Your car’s air conditioning works through a compressor, a refrigerant, and an evaporator. Air conditioners cool the interior air by forcing special chemical compounds to evaporate and condense over and over again in a closed coil system. These compounds are refrigerants that have properties allowing them to change chemical state at relatively low temperatures. Air conditioners also contain fans that push your cabin air over these cold coils filled with refrigerant.
When hot air flows over the cold coils of the low-pressure evaporator, the refrigerant inside absorbs the heat and changes from a liquid state to a gaseous state. To ensure it continues to cool effectively, the compressor puts the refrigerant gas under high pressure which converts it back into a liquid. All the extra heat created by compressing the gas is then removed from the system using a second set of coils called condenser coils and a second fan. When the refrigerant gas cools down, it becomes liquid again and the process starts over. It’s like an elegant, endless cycle designed to keep you cool: the liquid refrigerant is converted into gas as it absorbs heat, then it is compressed and turned back into liquid so it’s ready to absorb heat from the air inside the car. Magic… or science to be precise.
Car air conditioning recharge involves removing the old refrigerant gas from your air conditioning system and replacing it with new refrigerant, so your air conditioning can cool again. When wondering where to get an air conditioning recharge service, your garage should be your first point of call, but it might also be possible to do an air conditioning recharge yourself.
WHY DO AIR CONDITIONERS NEED TO BE RECHARGED?
In theory, the refrigerant should not need to be replaced. Because it just changes from a gas to a liquid inside the coils, it should last forever. Studies show, however, that as a result of this process, up to 10% of the refrigerant is lost each year as it permeates the system. Less gas of course means less cool air in your system, so a top-up every few years will allow your air conditioning to operate under optimal conditions.
Besides keeping your cabin cool, there are other reasons to ensure your air conditioning is working as well as it can. You can also improve your energy efficiency if the refrigerant is at its capacity, as there is less strain on the system and the engine.
Air conditioning doesn’t just provide car comfort during the hot summer months; it can also be used in winter to defog your windshield, which is another important reason to recharge your air conditioning unit. Air conditioning systems create dry, warm air instead of the usual humid air outside in winter, which can clear your windshield much faster than your regular blowers.
HOW OFTEN SHOULD I RECHARGE MY AIR CONDITIONER?
When to recharge the air conditioning is an important question, as the service is not always the cheapest. Air conditioning is not checked as part of an MOT test, so it’s important that you include recharging as part of your vehicle’s regular maintenance. The lifespan of the air conditioning gas in a car depends on the car manufacturer, but most manufacturers recommend having your air conditioning regassed once every 2 years.
IS IT POSSIBLE TO RECHARGE YOUR AIR CONDITIONING YOURSELF?
The cost of air conditioning recharge is one of the reasons why some people might consider doing this DIY. In a garage, prices are usually quite standard and depend on the type of refrigerant gas your car uses. The vast majority of cars on the road in the UK use one of two types of refrigerant – R134A and R1234YF. If your air conditioning system requires R134A gas, the recharge cost is £49.95. For vehicles that require R1234YF gas, the recharge cost is £129.95. In short: it’s quite expensive.
However, you can buy air conditioning regas kits if you want to try it yourself and save money. If something goes wrong, however, you risk ending up with a very expensive repair bill. Specialists may also have a better idea of how to check for leaks and other issues with the air conditioning system. There are also safety issues to consider. If the refrigerant gas comes into contact with your skin or eyes, it can cause painful frostbite burns.
You will need a canister filled with refrigerant and a valve to attach it to the AC system, as well as screwdrivers, goggles, gloves, and your car’s manual or handbook. A gas canister and valve typically cost around £60 and you get a £10 refund when you return the valve. One cartridge can be used to fill three air conditioning systems, so in theory, you’ll make big savings compared to garage prices.
If you want to do it yourself, there are three steps: Locate the air conditioning fill port, attach the top-up gas, and simply fill.
Use your manual or handbook to locate the air conditioning fill port, often called the low-pressure port. The manual will also tell you what type of gas you need to buy if you’re unsure. Some covers under the hood need to be removed before accessing this port.
Remove the plastic cap that is often secured using screws and bolts and attach the valve. Start the engine and set the air conditioning to the coldest setting. Let it run for at least three minutes, then check the pressure on the valve. If your air conditioning needs regassing, the valve will usually give a low reading (in the white zone).
Shake the gas cartridge, then connect it to the valve. Recharge by pressing the trigger for a few seconds. Go back and check the pressure again for an updated reading. Continue until it’s in the green, so above 25 PSI. Before finishing, check the air conditioning again by turning it on and it should blow cold. If the air conditioning does not hold pressure and cannot reach the green section of the PSI gauge, there is likely a leak somewhere in the system and it will require a specialist to check and repair it.
DO AIR CONDITIONER RECHARGE KITS WORK?
Air conditioning recharge kits have the potential to save you a lot of money. But do they work? The short answer is: sort of.
Yes, they can absolutely top up the air conditioning refrigerant in your system so it will blow cold air again.
However, since your vehicle’s refrigerant is supposed to last forever, if your sealed air conditioning unit is losing refrigerant, it could be due to a leak. If your refrigerant can leak out, air and contaminants can get in and that’s extremely bad.
Now, a small leak isn’t so bad. A £15 recharge yourself can revitalize the system with refrigerant for the entire summer season if the leak isn’t that big. The same problem will occur again the following year, but as long as the leak hasn’t gotten worse, you can repeat the process and avoid going into the workshop and having an expensive repair. Some people treat this as part of their car’s annual maintenance. Some kits also come with a sealer to help eliminate small leaks, which is an added bonus. You must be careful, however – putting anything into the system that your manufacturer does not recommend can have adverse effects.
A recharge kit only injects refrigerant into the system. It does not remove any contaminants from your system and does not clean it, and an AC machine is needed to decontaminate all the air in the system. If there is a leak, it also means that even though a kit will temporarily recharge the air conditioner, it will lose refrigerant much more quickly.
There is also the additional concern that if you use a recharge kit yourself with little or no experience, you could overpressurize the AC system and cause premature compressor failure. This can be very costly. It might be worth paying a garage to recharge your air conditioning rather than paying for repair costs. Taking it to a garage will also get you additional services, like compressor oil change, which will be essential to help maintain your air conditioning system in good condition, especially if it’s a car over 4 or 5 years old.