Why Car AC Compressors Tend to Fail in Hot Weather


Jan 13th, 2020

Why Car AC Compressors Tend to Fail in Hot Weather

A few decades ago, the air-conditioning system was a piece of optional equipment added to cars. Today, that narrative has changed. The air-conditioning system is now standard equipment on almost any vehicle you come across.

The air-system system consists of different parts, one of which is the air conditioning compressor. 

The air conditioning compressor, as the name suggests, compresses the refrigerant and pushes it to the air condenser, facilitated by the drive belts.

Car Mileage and AC Compressor's Life

People drive their cars in different conditions and terrains, so determining the exact life span of a specific component can be a bit of a challenge. Nonetheless, the lifespan of most parts can be estimated. 

Different factors affect the longevity and serviceability of the AC compressor. One such factor is the car mileage, and another is age in general. In the world of cars, age typically translates to mileage. 

Increased mileage leads to an increase in the wear and tear of different components, including the air-conditioning compressor. The result is a drastic decrease in cool air from the air-conditioning system. In most cases, the system starts to fail to cool the cabin. 

Running the air-conditioning system regularly and properly goes a long way in extending the longevity of the air compressor. In most cars, the air-conditioning compressors are used for heating as well as ventilation. In case you don't use the air conditioning compressor for this function, it is recommended that you run it for more than 10 minutes monthly, including the winter months.

If your car’s air-conditioning system no longer delivers the desired level of coolness, it could be that the AC compressor is starting to fail.

Why Do AC Compressors Tend to Fail More in Dry and Hot Weather?

Below are the primary reasons why AC compressors tend to fail more in dry and hot weather.

1. Dirty condenser coils

The roads during summer are typically dusty, and tiny particles float in the air. Some of these particles collect on the condenser coils, affecting heat expulsion from the system. 

Over time there will be a pressure build-up that will make the compressor work at high temperatures. Eventually, the compressor will no longer be able to keep up and will consequently fail.

2. Clogged refrigerant lines

The compressors push the refrigerant using refrigerant lines. In case these refrigerant lines become clogged, there will be a subsequent pressure build-up and rise in temperature resulting in the compressors failing.

3. Too little refrigerant

The refrigerant should be maintained at a constant level. If it falls below this level, the air-conditioning system will be forced to work harder to ensure the refrigerant is pumped through the unit. Over time, this will put a strain on the system and can result in the breakdown of the compressor.

4. Improper lubrication

Improper lubrication of the compressors during summer will strain the air-conditioning system and cause the compressor to fail.

What are the Signs of Air Conditioning Compressor Failure?

Below we look at some of the telltale signs of an AC compressor failing.

1. No cool air

The air conditioning system once turned on, ensures that cool air will circulate throughout the car's interior. If you turn the system on and it doesn't lower the cabin temp after a while, the chances are that the compressor is not functioning as desired.

2. Noise

Noises that come from the compressor, such as squealing or loud knocks, can imply undesired contact or airflow issues. If these issues are severe, they may cause the compressor to fail.

Tips on Using the Car AC in Hot Weather

Using the AC in summer can be quite a dilemma because the AC system gets worked out in hot and dry weather conditions. Then, of course, the AC is most needed when the weather is hot. The trick is to learn how to use it properly. In summer, temperatures can get so high that turning the AC to full to drive away the heat seems the most logical thing to do. However, it often causes failure to the system.

To avoid such a fix, here are some tips on how you can efficiently use the car's air-conditioning system in summer. 

1. Expel the hot air before driving your car

Driving your car with hot air trapped inside is an unpleasant experience. Therefore, before driving away, you should first drive the warm air out of your vehicle. 

To do this, roll down your car’s rear window and then repeatedly open and close the driver’s door. In a minute or so, the hot air will be forced out.

2. Expel more warm air while driving

The AC of your car delivers better performance when you are driving compared to when your vehicle is stationary. To expel the hot air out of the car, leave the rear window open for about 30 seconds. It is even better if there's a sunroof that you can also open for a minute to expel the hot air.

3. Turn on the AC at the low setting

Set the AC low to ensure it doesn’t strain to meet the desired air temperature. At high settings, the AC will take air from the passenger's cabin rather than the air outside. 

The air outside the car tends to be at a lower temperature than that inside the vehicle. For this reason, you should set the AC to draw air from outside.

4. Change the AC components such as filter

Using the AC in summer tends to overwork its components. To make sure that it operates efficiently, regularly check its parts, such as the filter, and replace when needed.

Maintaining the AC Compressor

Several factors can make the compressor fail and replacing it is no doubt expensive. Fortunately, most of these factors are manageable and preventable.

Regular servicing and proper maintenance will help prolong the life of the compressor and prevent it from malfunctioning. If your car AC now uses a replacement compressor, remember that the replacement has a shorter lifespan than the original that came with the car. With proper maintenance and regular inspection, however, you can make it last longer than average. 

The air compressor operates at high pressures and requires specialised equipment to repair and service. For these reasons, any repair or replacement of the compressors should only be done by qualified mechanics.

Sam O.