Car Air Conditioning

How it works

The vehicle’s air conditioning system circulates refrigerant through a compressor, condenser, and evaporator. It absorbs heat from the cabin and releases it outside. Over time, some of this gas naturally permeates through the system’s rubber hoses, causing it to lose up to 10% of its refrigerant each year. This gradual loss makes the system less efficient.

How often should it be done?

Vehicle manufacturers recommend that you have your air conditioning re-gassed every two years. However, this frequency may vary depending on how often you use your AC. A dedicated re-gas service is necessary because this procedure is typically not included in a standard annual car service or MOT.

Key signs that your AC needs attention

You can spot the need for a re-gas by watching out for a few common signs:

• Warm air: If your AC no longer blows cold or is less cool than it used to be, the refrigerant level is likely low.
• Weak airflow: When the system has to work harder to compensate for low refrigerant, you may notice a decrease in airflow.
• Unpleasant odours: Musty smells from the vents are not a direct sign of low gas, but of bacteria and mould buildup. This signals the need for a professional service that includes a system deep-clean.
• Increased fuel consumption: When the AC system strains to cool the cabin, it puts more load on the engine and increases fuel use.

The dangers of DIY re-gassing

While DIY recharge kits are available, a professional re-gas is the safer and more effective option.

• Health and safety risks: Refrigerant is a hazardous chemical. Mishandling it can cause severe freeze burns to the skin and eyes.
• Risk of damage: DIY kits often just top off the gas rather than removing the old refrigerant, which can lead to overcharging. This can cause severe damage to the compressor and other components.
• Incorrect gas types: Modern vehicles use different types of refrigerant (R134a for most cars before 2014 and R1234yf for newer models). Using the wrong type can damage the system. A professional will know which is right for your vehicle.
• Undiagnosed leaks: A DIY kit cannot detect or fix the underlying leaks that caused the refrigerant loss in the first place, meaning the problem will recur.

The professional re-gassing process

When you take your vehicle to a qualified technician for an AC re-gas, the process generally follows these steps:

• The technician performs a performance test to assess the current cooling level.
• The old refrigerant and lubricating oil are safely recovered from the system.
• A vacuum test is conducted to check for any leaks.
• The system is re-filled with the correct type and quantity of new refrigerant and oil.
• A final performance check ensures the system is operating optimally.

Beyond re-gassing: Aircon maintenance tips

To get the most from your AC system and reduce the need for premature re-gassing, follow these simple tips:

• Use your AC year-round: Running the system for about 10 minutes every fortnight, even in winter, helps circulate the refrigerant and oil, preventing seals from drying out and cracking. It also helps demist windows.
• Change the cabin filter: A clogged cabin filter can restrict airflow and affect performance. Replacing it regularly helps maintain air quality.
• Consider a full service: Regular air conditioning servicing, as opposed to just a re-gas, helps maintain your system’s efficiency and prevent issues from escalating into expensive repairs.