Is there a service interval for the air-conditioner in cars? If so, what does it entail? In between, do I need to top up the gas?

Home owners have their air-conditioning systems serviced regularly, but most tend to neglect the system in their cars.

As with the engine, brakes or tyres, a car's air-conditioning system requires regular servicing. There are filters and components in the refrigerant piping loop that have to be cleaned, and drive belts to be replaced.

Even if your car's handbook does not specify a service interval for the air-con, it is a good idea to do so - at the very least, once every 60,000km or every four years, whichever comes first.

During servicing, the entire refrigerant network should be flushed. This would remove any foreign particles that may have been deposited from deteriorating elements such as the internals of the receiver-dryer or expansion valve. A proper job means replacing at least the receiver-dryer before refilling with fresh refrigerant.

A new air filter for the evaporator in the car is highly recommended because it inevitably picks up minute particles from the outside. A choked air filter creates an increased resistance to the air flow past the evaporator and naturally reduces the overall efficiency of the air-con.

The compressor can last as long as 10 years. Unless there has been a refrigerant leak, there is no routine maintenance necessary for the compressor except perhaps to renew the drive belt.

There is no need to top up refrigerant ("gas") in between maintenance routines, as the refrigerant system is closed-loop and the refrigerant is not consumed. If the refrigerant pressure is low, it just means there is a leak in the system which must be repaired.

Continuing to use a leaky air-con will ultimately cause permanent damage to the compressor.

Shreejit Changaroth