The Air Conditioner in My Car Is Blowing Hot Air – What Might Be the Reason?
As you go on about your daily commute driving your car , you notice that the usual cold air that the car air conditioner brings you is not there – instead in its place is a prickly warm air – you ask yourself why the air conditioner in my car is blowing hot air? And adding insult to injury, the heat is blazing outside, doubling your dilemma.
In scorching heat, one of the worst possible places you could be in is inside of your car without a working air conditioner. Temperatures in a closed space like this can surge to alarming levels.
If this happened to you or worried it might happen, you must first understand how the air conditioning system works before knowing ‘why the air conditioner in my car is blowing hot air’ or what causes AC in the car to stop working entirely in order to recognize the problems better.
How Does My Car’s AC System Work?
The air conditioning (AC) system in your car does not create the ‘cool air’. What it does is eliminating heat and moisture from the air inside of your vehicle and dissipates it outside, therefore, leaving you with cooler air. Air conditioning works by circulating the refrigerant through the system, converting gas to liquid and back again through its three main parts: 1. compressor, 2. condenser, and 3. evaporator.
The compressor is responsible for compressing the low-pressure refrigerant to produce a hot, high-pressure gas before pushing it onto the condenser. When the refrigerant is transferred to the condenser, the condenser cools it down by dispelling heat. During the process, the condenser also cools the refrigerant from a gas state to a high-pressure liquid state. The now-cooled refrigerant expands quickly, becomes a low-pressure liquid as it flows through the expansion valve. Then, it enters the evaporator where it turns into a gas state again before it flows out, while a fan blows air onto the compressor during this process. The refrigerant gas enters the compressor again, repeating the entire process.
Reasons Why the Air Conditioner in My Car Is Blowing Hot Air
- Refrigerant is Leaking
Refrigerant is a gas that is compressed to liquid by the compressor that flows through the air conditioning system. Its function is to make the temperature inside the car colder than the outside. This is done by absorbing heat from the inside and releasing it outside.
If an aircon does not meet the appropriate refrigerant levels, other parts will not also function well. Also, the refrigerant will not circulate properly in the system and will reduce its operation if it is leaking.
A refrigerant leak is difficult to locate. Why? Since it can take place at any point in the air conditioning system. If you are lucky, you may see an oily residue around the unit hose connections, where leaks are usually found. But more often than not, you cannot see any signs of a leak.
Refrigerant is converted to liquid and gas alternately while flowing through the system, but if there is a leak, it discharges in a gaseous state when exposed to the atmosphere which makes it hard to identify the exact location of the leak. Also, the air conditioning vents will blow warm air instead of cold because the refrigerant evaporates before reaching the vents due to the leak.
Some car technicians inject dye into the AC system to trace the location of the leak and they can close the leak using a sealant. In the case of a large leakage and beyond repair, they might need to clear out the refrigerant totally and replace it. Don’t try to replace refrigerant yourself because it might be flammable or toxic. Only the repair shops can do this and they have complete tools for it.
So in summary, one of the most common causes of an AC blowing hot air is a refrigerant leak, and this might be the answer to your question as to why the air conditioner in my car is blowing hot air.
- Compressor Is Damaged
The compressor is said to be the heart of a car’s air conditioning system. Its function is to circulate the refrigerant through the system at all times so it is what keeps the refrigerant moving and it compresses the refrigerant using high pressure onto the condenser.
If unused for a long period, like the winter season where an aircon is not needed, it can shock the compressor when re-engaged, which will surely require a repair. The compressor itself can rarely have issues aside from failure due to inactivity so it is advised that once in a while you have to turn your car’s aircon unit on. In effect, using your car aircon’s compressor regularly can prolong its life.
- Condenser Is Blocked
When the refrigerant absorbs heat from inside the car, the condenser keeps the refrigerant cool to maintain the cycle with the help of the cooling fans. It dispels heat from the refrigerant that was released by the compressor. The air that comes through the front of the car while it is moving is how the condenser carries out its function. If the condenser cannot do its function, the system will not operate as intended and will blast warm air.
Checking the condenser since it is located at the front of the vehicle, debris and dirt can sometimes clog it and stop air from going in, thus disrupting the cooling process of the refrigerant. The system will then continue to work with the heated refrigerant, resulting in warm air coming out.
So if the air conditioner in my car is blowing hot air, I make sure that the condenser is not clogged or not damaged.
- Condenser Is Damaged
If there seems to be no blockage in the condenser, it can be because it is damaged. If you noticed that the problem occurred after a fender bender, there is a chance that your condenser might be broken. It can also be because of debris or other hard objects piercing through your car grate. The only way to fix this kind of problem (puncture damage) is by replacing it.
- Electrical Issues
Your car’s electrical system provides the needed power supply to run the AC system. If some of the AC components require electricity to function and the electrical system cannot deliver, the unit is less likely to blow cool air.
Fixing an electrical problem will be difficult because it may involve dismantling the system. It is best to let the professionals take care of the issue if it involves the electrical system.
- Cooling Fans
Cooling fans help the condenser and compressor provide proper cooling. If the fans stopped functioning, after some time, your AC will start blowing hot air. Debris causing damage or an electrical issue can also be the reasons for the cooling fans to stop working.
Other Uncommon Issues
What we have mentioned above are the most common issues that happen during a car’s aircon malfunction. But there are also other problems that can occur due to the following:
- Low Charge AC
The air conditioner running on low charge possibly is the reason why the air conditioner in the car is blowing hot air. It simply means that the AC system needs an additional refrigerant. Low charge AC provides inadequate cooling.
- Bad Compressor Clutch
A part of the compressor that is essential in connecting and disconnecting the compressor from the engine’s mechanical power is the compressor clutch. To make cooling possible, the clutch connects the compressor to the engine. If this clutch disconnects, the compressor will not function properly.
- Expansion Valve Is Not Working
Some cars do not have an expansion valve in their AC system but if it does and the expansion valve is not working, the sign would be the aircon blowing hot and cold air alternately. The expansion valve allows the high-pressure refrigerant in a liquid state to pass through the small opening, lowering the pressure of the refrigerant where it becomes very cold. If it is blocked, the flow of refrigerant will also be blocked.
What Causes AC in Car to Stop Working
- Due to Overheating
One of the main causes of AC in a car to stop working is when the air conditioning system tends to overheat during extremely hot days which can cause some of the components to malfunction or break and make the air conditioner to stop working.
The possible reasons listed above as to why the air conditioner in my car is blowing hot air might also be what causes AC in a car to stop working.
- Electrical Issues
Your car’s electrical system provides the needed power to run the air AC system. It is also designed to shut down in case there is a defect in the system to prevent further damage to other AC components. Check if there is a sign of a broken fuse or frayed wires. Because something as simple as a faulty fuse may also cause the operating system to stop working.
- Cabin Air Filter and Blower Motor Damage
Some cars have a cabin air filter, depending on the make and model. The cabin air filter cleans harmful contaminants from the air inside the car. If your car has one, check if it has already collected dirt and other grime that may have stopped air circulation entirely in the ventilation system. An unclean cabin air filter can damage the condenser and the blower motor that pushes air through the vents. When the blower motor is damaged, it also blocks air from passing.
- Blocked Air Intake
Air intake occurs at the vent near the windshield, and the other is through recycling the air inside the car. Anything blocking these intakes will prevent air to come out from the vents.
Steps on How to Clean Air Conditioner Vents in Car
A car’s air vent may look clean, but it can be full of pollutants you cannot see and you can inhale when the air conditioner is switched on. It can also be hard to clean manually by just using a cloth. Here are some tips on how to clean air conditioner vents in a car.
- Change Cabin Air Filter. Your car’s air filter must be changed regularly, depending on what is suggested on your car manual, or more frequently if you live in a highly polluted area.
- Using Compressed Air. Spraying compressed air can blow out dirt sticking in the vent surfaces. Keep in mind to only use products that are safe for vent cleaning.
To do this, first, clear off the debris in the exterior vent intake. Then, spray the can of compressed air to the air intake vents found near the windshield. Do this while the car air circulation is flowing, this is to allow the air to escape. Then turn both the AC system and engine off before spraying into the cabin air vents.
- Vacuum. A wet/dry vacuum can be used to cautiously suck in the dust and dirt in your car air vent.
Benefits of Well-Maintained Car Air Conditioning System
After learning how to clean air conditioner vents in car, did you know that you can have a lot of benefits by having a clean and well-maintained car air conditioning system aside from it provide us the comfort of cool air on the days we need it?
Here are the advantages:
- Cleaning your car’s air vent improves the air quality that flows around your car. It removes the pollutants and allergens that can affect your health.
- It prevents the growth of molds in your car’s AC system.
- It helps retain your car’s fresh smell.
- Regular cleaning will help maintain the quality of all the other components in your AC system.
- It keeps the temperature of the engine within optimal levels, lowering the chances of damage.
- It also improves fuel efficiency. If the air conditioning system is not functioning as intended, the car tends to burn more fuel when the air con is switched on.
Cars are used for our convenience as we travel riding them. But how can a ride in a car be convenient when its air conditioning system does the opposite like having hot air instead of the cool, breezy air, right?
Like what we have discussed in our other article, a car’s air conditioner is a system. Components in a system must efficiently work in unison to complete its function and an issue with one component can cause additional problems to other components. Fortunately, most of the car aircon problems are repairable.
So whenever you encounter the same problem and ask yourself why the air conditioner in my car is blowing hot air, you now have an idea of where to start looking.