Surprisingly, over 10% of air-con gas escapes through the system each year. This means that the power of the system drops significantly over time.
Vehicle air conditioning systems can lose refrigerant gas over time, especially if they aren't used regularly, which means that they may not work as well as they should. This is why car manufacturers recommend your air con system is recharged with gas and lubricant every 2 years. This service is not part of routine vehicle servicing, so if your vehicle is more than 2 years old it’s probably due an air con recharge.