Have you ever overheated in a car because the AC was broken? Here's a quick guide on how an air conditioner works, why it breaks, and what you can do about it.
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Method 1 of 2: Understanding Car Air Conditioning
Step 1. Know that AC is actually like a refrigerator, only it looks different
Air conditioners are designed to transfer heat from one place (in your car) to another (outside). We won't talk about every type of AC in every car brand here, but the explanation about AC here will provide an understanding for you to be able to speak clearly to a real AC mechanic.
Step 2. Understand the main components of a car air conditioner:
- Compressor: Compresses and circulates refrigerant in the air conditioning system
- Freon: on modern cars, freon uses the R 134a type, and on old cars uses freon R 12, which is now increasingly expensive and rare, also requires a permit for sale. Freon's job is to dissipate heat.
- Condenser: to change the form of freon from gas to liquid and dissipate heat from the car.
- Expansion valve: serves as a kind of valve that functions to lower the pressure of the refrigerant fluid, measure its flow and atomize it.
- Evaporator: This section cools the air that is blown through it, so that the air cools down.
- Receiver/dryer: It acts as a freon/oil filter, removing moisture and other impurities.
Step 3. Understand the air cooling process
In essence, the compressor compresses the frion and sends it to the condensing fin. Generally these fins are located on the front of your car radiator.
- Pressing the gas will make it hot. In the condenser, the heat will increase, and the heat captured by the freon will be released into the outside air. When the temperature of the freon decreases to its saturation point, the freon will change its state from gas to liquid. The liquid then flows through the expansion valve, into the evaporator, and the liquid portion of the refrigerant absorbs heat from the air through the fins and vaporizes it.
- The AC blower blows air through the cool evaporator into the interior of your car. Freon returns to the initial cooling cycle.
Method 2 of 2: Repairing AC
Step 1. See if the freon is leaking (meaning there is no substance that absorbs heat)
Leaks are easy to detect but not easy to repair without disassembling them. Most auto parts stores provide a liquid dye that can be added to the system to detect leaks, and there are instructions on the can. If the leak is large enough, the system does not have sufficient pressure to work. Locate the bottom valve and check the pressure.
Do not use anything to poke the valve to see if any gas is coming out, this is not allowed. this is called venting
Step 2. Make sure the compressor is running
- Start the engine and air conditioning, check under the hood. The ac compressor is usually a pump-shaped object with an iron and rubber hose on the side leading to it. There may not be a cover, but there are two valves in the shape of a bicycle valve. The pulley at the front of the compressor is the outer pulley and the inner connection that will rotate when the air conditioner is turned on.
- If the air conditioner and blower are on, but the center of the pulley is not rotating, it means that the compressor is not rotating. This could be due to a blown fuse, a wiring problem, a faulty AC switch, or a system lacking Freon. In general, AC systems have a safety system that will cut off the current if there is not enough freon.
Step 3. See other sections that may not be correct
Other problems that may occur with the air conditioner are a broken switch, blown fuse, blown wires, blown fanbelt (resulting in the compressor not turning), or damaged seals inside the compressor.
Step 4. Feel if there is cold air
If there is cold air but only a little, it's probably just a lack of pressure, and you can add freon. Usually the spare parts store provides freon along with charging instructions..
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Don't overfill! Adding more freon than recommended will not increase its cooling capability, but will actually reduce it. Actually, a more expensive tool at an AC repair shop will monitor the actual condition of your air conditioner when adding freon. As the cooling decreases, reduce the pressure until the ability increases again.
Pocas cosas
Tips
- If you suspect a damaged cable, compressors generally have wires leading to electrical switches. Locate the connector on the cable and remove it. Take enough cable, connect the cable from the compressor to the plus (+) terminal on your battery. If you hear NO, the electrical switch is not damaged, and you should check the wiring on the side of your car. If you don't hear anything, the electric switch means it's faulty it should be replaced. Ideally, if you can do this test while the engine is running, you can see if the compressor is running. Be careful with your fingers or your clothes don't touch the rotating parts. Thus, the damage can be ascertained not from the switch, but may be caused by a loose and slippery belt that cannot apply sufficient pressure.
- Freon that you may need is HC12 which is slightly more widely used in Europe. R12 works better than R12 or R134a. It is more flammable. HC12a is not permitted in many American states, including Arkansas, Arizona, Connecticut, Florida, Idaho, Iowa, Indiana, Kansas, Louisiana, Maryland, Montana, Nebraska, North Dakota, Oklahoma, Texas, Utah, Virginia, Washington, Wisconsin, and District of Columbia. HC12a is more environmentally friendly than R12 or R134a, but because HC12a contains hydrocarbons, it can cause VOC emissions. This type of Freon must be ordered via the internet because it is not available in stores. The problem is that the AC repair shop may not be able to do it because it requires special tools. Using R12 or R134a is a safer choice.
- Sometimes the problem is not with the freon. There may be a problem with radiant heat emanating from the engine bay, which reduces the ability of the air conditioner to cool. You can try to insulate / wrap the AC cooling hose near the engine to reduce the influence of engine heat on it.
- If your car's air conditioner leaks even though the drain pipe is clean, there may be water entering the air conditioning system while driving in the rain.
- There will be a small amount of oil in your system.
Warning
- Checking freon by pressing the valve to see the gas coming out is illegal because it releases harmful gases into the air. (Don't do it with R 12!) While it's legal to add to a leaky system, you should be sure of your local regulations. Some areas have laws that prohibit this because of the emissions it creates. Releasing freon, including R134a, is also illegal in America, so stick to it.
- If you have reason to suspect that your freon is leaking entirely (the pressure gauge you buy at the parts store shows 0 PSI; the compressor won't spin because it detects no pressure), then it's best to leave it to a specialist unless you're a pro. But if you are reading this article, it means you are not an expert. The reason is, completely leaking freon cannot prevent air and moisture from entering the system through the leak gap. Air and humidity are the main enemies of the air conditioning system. How this can damage the system is beyond the scope of this article, but that being said, there should be no air or moisture in the ac line. The dryer must be replaced, because in this case the dryer must have absorbed the moisture and is no longer functioning, and before you replace it, the system must first be vacuumed to remove all the air and moisture from it. Let an air conditioning expert do this, and you only have to pay for the leak repair fee. But if you try to fix it yourself, you may have to do it again a few months later, also damage to the compressor, condenser, expansion valve, can also be damaged by it.
- Avoid major freon leaks. At this time it radiates, will cause very cold air that can freeze your skin.
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Be careful when changing your system from R12 to R134a. There are conversion kits you have to buy at the store, maybe even at WalMart, called "black Death Kits" by AC mechanics. Often, the new R134a freon will not work with the old oil and will burn your compressor. Oils in systems with R12 contain chlorine which will destroy PAG or POE oils in systems with R134a freon. The only way is to replace all the oil in the compressor, replace the Dryer, and rinse all lines, evaporator and condenser with a special tool and then vacuum, and fill R134a about 70-80% by weight of R12, and cooling conditions are more worse than R12. It's easier to stick with the R12 by buying it on eBay. You need permission to buy/sell R12.
Be aware that the above warning may be controversial. Some ac mechanics claim that they can convert without any problems
- Watch out for the rotating fan and belt!
- You may not be able to find a repair shop that will only charge freon, if they suspect a leak in your system. If you repair the leak yourself, it is legal to fill the freon with R134a, but not with R12. But getting a license to buy the R12 is easy, online and only costs $20.
- Do not connect the freon can, or leak detector can through the high pressure line in the system. This is usually marked with an H or HIGH mark or by a red valve cap. The bus can explodes and hurts you.
- HC12 and R-134A are not flammable at room temperature, but can cause high pressure and temperature under certain conditions (contact with some reactive metals). They also absorb oxygen, so don't release them into the air in tight, unventilated spaces.
