How to Make Car AC Colder?

I am sitting here at a traffic light during summer month of June. In this scorching heat I am thinking how can I make my car AC colder? I mean, my car ac blows cool but not ice cold. I am sure everyone wants their car air conditioner to work at its best, especially during scorching heat.

The most obvious ways to improve the cooling is to get the AC gas refilled and get a new cabin filter. The gas (liquid refrigerant) takes care of cooling. And new cabin filter will allow the AC blower to have free-flowing passage. 

After reaching home, I hopped on the internet to confirm if I am right. In this article, I discuss more on this and then some more. Here’s what I found out that will most likely solve your car AC problem:

make car airconditioner cool again

How Car’s Air-Conditioner Works?

All air conditioners, irrespective of the car make works in a similar manner. A car’s AC unit is comprised of 5 main components

  • Compressor
  • Condensor
  • Expansion Valve
  • Receiver | Dryer | Accumulator
  • Evaporator
Car ac parts location
AC component location (source: clearmechanic.com)

The air conditioning system is airtight. Or I should say that it’s pressurised from inside by refrigerant (AC gas). Every car manufacturer specifies the required gas pressure in the workshop manual. This is generally between three to four pounds. Let’s see what all these components do:

1) Job of Compressor: As the name suggests, the compressor compresses the AC gas to convert to fluid and pushing it through the refrigerant line. Since the system is pressurised in this area, it’s called “high side”.

2) Job of Condensor: Condenser is a radiator-like heat exchanger that helps cool down the refrigerant as it’s heated during the compression cycle. In the condenser, the refrigerant passes is cooled by air that gushes through the condenser.

3) Job of Expansion Valve: Expansion valve is a restriction in the pipe. This separates the high pressure and low-pressure areas of AC system. As the liquid refrigerant passes through this valve and enters the low-pressure area, it turns back into gas.

4) Job of Reciever | Dryer | Accumulator: In the gaseous state, the refrigerant enters the dryer. This removes the moisture from the refrigerant.

5) Job of Evaporator: Now, the dried cold gas is passed through the evaporator. The evaporator is the only component of an AC system that’s installed under the dashboard. This AC Fan then blows air through the evaporator core to cool down the hot air. This air is then blown into the cabin through air vents. The heat exchange is completed and the refrigerant continues back towards the compressor to start the process all over again.

car ac working diagram

How to Make Car AC Colder?

Wonder why your car AC is not cooling like it use to? Now that you have learned about how car air conditioner actually works, you must have already got some ideas to fix it. Here are some things you need to check when your car’s air conditioner is not cooling effectively or your passenger say that your car AC is not cold enough.

1) Clogged cabin filter: This is the first thing you should check as it’s also the easiest to do. The cabin filters cleans the air flowing into the passenger compartment. Some of them even have anti-bacterial properties.

However, over time, they get clogged up, especially if you drive in a dusty environment. It’s generally located under the glovebox area, so inspect it and replace if it looks dirty. They are quite cheap.

Replace dirty cabin filter

2) Low refrigerant gas pressure: The AC system is a pressurised unit but it’s not 100% leak proof. Some gas pressure might leak out of the system over the time of multiple years. When this happens, the compressor does not work properly.
All you need to do in this case is get the gas refilled from refrigerant charge port located under the hood. You can get it done from a workshop or you can also buy a DIY kit. I found this car ac recharge kit on Amazon (checkout the latest price here). Here’s how to do it:

3) The refrigerant or Compressor have got old: Just like everything on a car, there is wear and tear on the AC system also. The refrigerant or ever compressor can wear out over a period of time. When this happens, it gets difficult for it to turn to gas from a liquid state.

This results in less effective cooling. First, try with replacing the refrigerant (R-134a Freon) but if that does not fix the issue then get the compressor checked by a technician.

4) Faulty temperature controller: The temperature controller on today’s cars are mostly electronic. They don’t fail often but when they do it can get difficult to diagnose it. On most cars, a simple ECU scan should find out the error code.

If you don’t have the scanner then try to put a temperature controller in different settings to see if it results in temperature change. If you do diagnose a fault in it then have an auto electrician take a look at it. Buying a now temperature controlled will be your last resort. See this video to learn more about this issue:

5) Faulty Compressor Clutch: The AC Compressor has an electromagnetic clutch. This clutch engages and disengages the compressor to maintain proper refrigerant pressure in the system. You might have noticed that when you push down on the throttle pedal all the way down, the ac compressor clutch disengages. That’s why it’s recommended to drive smoothly for proper cooling in summers.

But sometimes the clutch is so worn out that it can’t function properly. When this happens the compressor won’t be able to push freon gas through the car AC system. Adjusting the clutch might solve the issue but it’s recommended to just replace the AC compressor clutch.

6) There could be Air in the system: Sometimes it can happen that condensor is working fine and gas pressure is also showing right on the gauge. But still, the AC is not cooling as it should. 

In such case, it’s good idea to empty the gas in the system and refill it with fresh refrigerant gas. This issue happens when there are air pockets in the AC system. Your previous mechanic could have filled it up with bad refrigerant that’s mixed with air, by mistake, or due to shady practice. Watch this video below to learn more about this issue:

Checkout: What to do if car battery fails

Are there any car AC additives?

Nowadays, there are many additives available for the air conditioner system. These are basically added to the refrigerant to revive it. But can it fix the year’s worth of wear and tear? According to a number of claims on the internet, I found out that they do seem to work pretty well as most said that it made their car ac cold again. Adding these additives basically removes a layer of oil that gets collecting in the coils. This collected oil hinders the heat exchange and reduces cooling. You should definitely try using AC refrigerant additive, also called “AC SRA”. I found an SRA on Amazon with some good reviews- Check the latest price.

Park car under a shade

How can you cool down your car quickly?

Even if your car AC is working fine, you can take some steps to increase the cooling efficiency. Getting in a car that’s been parked under sun can feel awful. Do this to cool down faster:

1) Park under a shade: Don’t let the cabin get hot by parking under a shaded area. You might say that this is quite obvious, but we often forget to do it. Buying aftermarket window shade or curtains is also a good idea.

2) Adjust the air vents: There are multiple AC air vents in a car but do we need them all when we are driving alone? Off course, you are better off just using the driver side and centre ac vents. Switching off the passenger and rear ac vents will considerably increase the air flow in the driver’s area. Also if you have dual zone climate controls then that can also be adjusted to optimize the cooling.

3) Clear out the hot air from the cabin: When you get in a hot car, you need to try and remove the hot air from the cabin. The best way to do this is to crack the windows (Open sunroof also if you have that) and run the AC with outside ventilation. Switch back to the recirculation vent mode after the hot air is released after 2-3 minutes. This is the best method to use car air conditioner settings.

4) Drive smoothly: The car AC unit runs off of the engine itself. In some cars, when you put the pedal to the metal, the AC compressor does not get enough power to pressurize the system. Yes, the air will keep flowing at the same rate but it won’t be cool. For effective cooling, you should drive gently and smoothly without straining the engine for more acceleration.

After going through this article you must now know ins and out of the car air conditioning system. Airconditioner is a pretty neat solution hey. It might go bad sometimes on us but I know that I can live with it during summers and I keep trying ways to make it super cold. If you followed these steps, you won’t say that the car AC is not cold enough.

Even if you think that your AC is working fine, you should definitely try some of the tricks mentioned above. I highly recommend replacing the cabin filter at least. Let me know in the comments if this article helped you in fixing your car ac. Let us know in the comments if you think we missed something.

Also See: 4 Tips to Increase Tyre LifeImportant Garage Tools you Should Own

FAQs about Car Air Conditioner System:

What are the Most Common Car AC faults?

Car Air-Conditioner cooling issues could be due to either of these reasons:

1) Leaking refrigerant
2) Electrical issues
3) Broken condenser
4) Blocked/clogged condenser
5) Bad compressor
6) Faulty cooling fans

Will adding Freon Make Car AC Colder?

Yes, adding fresh Freon gas will certainly improve cooling if the gas pressure is less. However, before adding Freon a technician should perform a leak test. Overfilling the gas is not recommmended. It needs to be within spec.

How often should you replace Freon gas in Car AC?

There is no need to replace Freon gas if the AC is working fine. Freon only needs to be added if the gas pressure has gotten low due to a leak.

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Siddharth Sharma

Siddharth has always been passionate about Cars and Bikes. He was the kind of kid that always had the latest Auto magazine in his school bag. He had this dream- to become a professional racecar driver. Finally, in 2012 he found himself racing as a rookie driver in the Polo R Cup national racing championship. Over time he had to readjust the sail and get into automotive journalism to continue enjoying machines on wheels.