Why does my air conditioning seem less efficient?

Over a period of time, air conditioning systems can lose some (or sometimes all) of their effectiveness. This is mainly caused by drivers not using the system all year round and, of course, not understanding the importance of regular servicing. Most vehicle manufacturers advise running the air conditioning system at least once a week throughout the year.

The biggest problem by far is loss of the system’s refrigerant. Most air conditioning systems have a seepage rate of around 10% a year but this can increase dramatically in systems which are not used for long periods. This is particularly so during the winter months due to an increase in expansion and contraction of components.

Operating a system with a low level of refrigerant not only places the system under strain as it struggles to achieve the desired temperature but, as the lubricant is carried around the system by the refrigerant, can also lead to serious (not to mention expensive) problems such as a seized compressor.

As well as delivering cold air, the air conditioning evaporator also acts as a wet filter, removing pollutants from the air before they enter the passenger compartment. In systems which are not used regularly, the heater box is an excellent place for bacteria to multiply leading to unpleasant odours when the system is used.

An air conditioning health check can easily be carried out (when the vehicle is serviced for example.) Chemical treatments are available to remove any bacterial growth and systems can then be recharged as necessary with any faults or leaks located and repaired before a potentially expensive failure occurs.