Case Studies

That’s Hot! – Air Conditioning and Climate Control Diagnosis and Service

Air Conditioning In Modern European Autos
From the entry-level to the top-of-the-line, every modern car comes equipped with climate control. It is not just a feature; it is the standard. Audi, BMW, Mercedes, Mini Cooper, Land Rover, and Volvo, all have different designs, but the theory of operation of reach of these systems is the same.

Even though you might not get the heated seats or automatic climate controls, your car will still have A/C as standard. Interior comfort is one of the many reasons why we need a good air conditioning system in our cars. Often thought of only as a summer convenience, did you know that in modern cars, air conditioning is also used when the heat is on, to dehumidify the air inside the cabin, and to aid in defrosting the windows?

But then again, no matter how good anything was in beginning, it will always come to an end. Air conditioning is no different. They sure make our life a lot easier and more comfortable, but with time their cooling also starts to fade, and the system requires service.

Why Is My Air Conditioning Not Cold Enough?
Well, when you talk about A/C not working properly, it means that your A/C is malfunctioning. Now malfunctioning can be caused due to several reasons. But when we talk about A/C not being cold enough, well then, the reasons are always obvious.

If your vents are pushing less volume of air or you see dust or the air smells different, that will be a bad cabin micro-filter.

But otherwise, it could be a failed component or it’s just out of refrigerant.  To understand it better let’s first understand the working of a modern air conditioning system.

The functioning of an air conditioning system is nearly universally the same in almost all cars. The first thing you should understand is that your A/C does not create or generate cold air, it simply converts hot air into the cold. Your A/C system does so by either regulating the cabin air or bringing it in from the outside.

Understanding Air Conditioning Operation
It all starts from one unit called a compressor. It is a device that is used to reduce the volume of gas by increasing its pressure. Due to an increase in pressure the temperature also increases. Now, this hot gas moves into another unit called the condenser. The condenser is like a radiator and as the gas moves through it, it loses its temperature while being at the same pressure.

This in turn converts the gas into a liquid. Now the liquid moves through a dryer which separates the liquid from any remaining gas. Then the liquid moves to a thermal expansion valve which then simply turns your hot high-pressure liquid into a cold, low-pressure gas. The cold gas is now passed through an evaporator which is also like a radiator.

The hot air from the outside or from your cabin then passes through the evaporator. As the hot air comes into contact with the cold gas, the air loses its heat and you get cold air from your vents.

Then the cold gas from the evaporator goes back into the compressor and a cycle is created. This is how your air conditioning works. We would call it a heat exchanger, moving heat energy from one area to another.

How and Why Does Air Conditioning Fail?
You might be wondering, how does this explain your A/C not cooling air.
There are two answers to that.

a. Any one of the many AC components has stopped working.

b. Your compressor has run out of refrigerant due to a system leak, or the normal loss because of age.

What Is Refrigerant?
A refrigerant or freon is a substance used to transfer heat from one area to another. Yes, it is the same substance that keeps converting into liquid and gas as explained above. With time your car runs out of refrigerant and you need to recharge it.

Without refrigerant, your compressor will not work, and your evaporator will not have any cold gas to convert hot air into the cold.
But how would you know whether you have a malfunctioning AC or you just don’t have enough refrigerant?

How Much Does A Simple Air Conditioning Recharge Cost?
The total cost of getting your refrigerant refill or A/C simply recharged will generally not be more than $270-$300, but if a component replacement is needed, then the cost can be considerably higher. This is why it is important to have your system professionally diagnosed and checked for leaks, so parts are not needlessly replaced, or refrigerant wasted.

How Often Do You Need To Recharge Your A/C System?
Recharging your A/C doesn’t come with a time period or expiry date. Refrigerant is not consumed with use, but over time does seep out of the system, though this often takes years. So there is no time limit or frequency to how often you should recharge your air conditioning. It depends on the area you live in and the amount of time you use A/C and at what intensity you use your air conditioning, and system integrity.

The Proper Repair And The Alternative
If you search, you’ll see all kinds of “do it yourself” (DIY) kits to “repair and recharge” your air conditioning.  In days gone by, 20 or 30 years ago, this sometimes worked, when A/C had a “sight glass” to view the charge level.

Today’s modern systems no longer have a sight glass, and instead, rely on very accurate (down to the level of ounces) proper refrigerant charge. Any of these DIY kits will almost certainly damage your vehicle’s A/C system, and end up costing you hundreds, if not thousands of dollars more. DON’T TAKE THE CHANCE.

The only true and permanent repair is to confirm system integrity, correct any leakage, or replace worn or damaged components. Then the system must be thoroughly evacuated (vacuum drawn on the system for testing), a leak detection dye is then added, and then the system is properly recharged with the correct refrigerant, while pressure is monitored. It’s just not worth the risk, do it right the first time professionally, and it’s good to go.

At Atlantic Motorcar, we’re all about providing our customers not only Great Service but also Value. We understand that “An ounce of prevention is worth a pound of cure.” (my mom would be proud I remembered that.), in other words, preventing, or catching problems like these brake lines early, can save you more than just money.

Questions, or if we can be of help in any way with service on your Audi, BMW, Mercedes, Mini Cooper or other European (and now Japanese) import, please contact us.

Our team of Service Specialists is here to help, for even the newest autos! (207) 882-9969.
Knowing, not just “doing”, that’s the Atlantic Motorcar Center way.


The Atlantic Motorcar Center Service Team

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