Air con light dashboard

Long car journeys can be stressful enough without the need to throw a roasting hot car, searing steering wheel and scorching leather seats into the mix!  With summer fast approaching, you will want to make sure your car air conditioning is in tip top shape and working at full capacity to ensure both driver and passengers (especially small children and the elderly) avoid any sweltering car trips.

If you are in any doubt that your car air conditioning is failing or needs a boost, it’s always best to get it checked out by a professional.  This blog takes a look at how car air con works and some of the signs that would suggest your air con might need a recharge.

How does car air conditioning work?

Before we look at the signs that your car air con may need recharging, let us just remind ourselves of the basics in how car air con functions.

The majority of air con systems are all about pressure.  Inside the air conditioning system is a compressor which contains a refrigerant (this is the gas that needs refilling regularly).  When the air conditioning is switched on, the compressor pressurises and circulates the refrigerant gas in one side of the system and converts it into a liquid in the other side of the system.  The liquid is turned into vapour and blown into the car.  It is the constant circulation of pressurised refrigerant through both sides of the system that keeps the car cool.

What does ‘recharging’ air conditioning mean?

As we have mentioned, air con systems work on the notion of pressure and therefore, must be completely sealed to operate properly.  Over time, the pressurised system can develop leaks.  Once leaks start, they will eventually cause enough refrigerant to leak out to the point where the air con will no longer be able to produce cold air.  Once the refrigerant and pressure level of an air con system drop too low, it must be recharged with pressurised refrigerant before it can function properly again.

Car air vents


3 symptoms of a low charge car air conditioning system

  • You are not being kept cool

A noticeable loss in the overall capability to keep your car cool is the most obvious symptom that your air con needs recharging.   If the air is not blowing as cold as it was before or is not blowing cold air at all, this is a sure sign that refrigerant pressure level has dropped too low and needs a boost.

  • You will not hear the familiar ‘click’ of your air con clutch engaging

When your air conditioning is on max, you should be able to hear the clicking sound of your air con clutch engaging.  It engages by a signal from the air con pressure switch, which reads the pressure level of the system.  When the pressure level drops too low, the switch will not activate (and therefore the clutch will not engage).  Without the air con clutch engaging, the system will not work at all.  So, make sure you listen out for that familiar ‘click’.

  • Visible refrigerant leaks

If you spot a greasy film on any of the air con components or fittings, or any pools of refrigerant underneath the vehicle, then this is a sign that has a leak has developed and refrigerant is being lost.  The refrigerant will continue to leak until the system no longer works.  This is a slightly more serious sign as there is likely to be a leak somewhere in the system that may need to be addressed before recharging the refrigerant.  If you suspect a leak, have your air con system inspected first to ensure that the air con recharge will address the problem properly.

Remember, recharging your air conditioning is not just about keeping your car cool, it also increases fuel efficiency too.  Recharging your air con will help you get the most out of your fuel tank; when your air con refrigerant is low the air con system struggles to cool the air and so works harder to try and produce cold air.  The extra work uses more fuel.  Similarly, it pays to recharge regularly if you do not want to have to pay out for expensive air con parts and repairs later on.  Looking out for the signs above will ensure that you and your passengers slide comfortably into their seat and waste no time pulling away for that chilled drive, no matter how high the temperature outside soars.

Check out our air conditioning services to ensure you stay cool, calm and collected or give us a call on 020 8460 3040 to discuss further.  We’d love to help.