Q1. Why do I need to have my air con serviced?

A. Vehicle air conditioning systems are not seal and forget systems. They consist of components with moving parts and therefore a poorly maintained system will not operate at maximum efficiency and become a drain on engine power. Manufacturers recommend a service every 2 years or 24000 miles (whichever is the sooner).

Q2. Why every 2 years - if I do not use the system regularly will the service interval not be longer?

A. One of the components of an air con system is the receiver/drier which requires changing periodically, regardless of the amount of time the system is operating. The level of refrigerant will eventually fall due to seepage caused by inactivity and general vibration of the engine. Inactivity allows the "O" ring seals to dry up. A system low on refrigerant is inefficient and a drain on the engine power.

Q3 What does the receiver/drier do and why does it require changing every 2 years?

A. The receiver/drier contains a desiccant to remove moisture from the system and once fully saturated will no longer carry out one of its main functions. It is also collects debris in the form of rust particles, metallic particles and any silica gel mush that might have broken away after the drier became saturated. In its latter role it acts in the same way as an oil filter and you do not change your oil without including changing the filter!

Q4. How does moisture gain entry into the system and what is the affect of moisture in that system?

A. All vehicle air con systems consist of some rubber tubing and moisture is attracted through the tubing by the extremely hydroscopic oil within the system. Moisture in contact with metal produces rust and flakes could become detached, circulate, and cause damage within the system components. Even if the rust does not become detached, it will weaken the metal and with pressures within the system in excess of 100 psi, a leak can quite easily manifest itself at any rust-weakened spot. Also moisture within the system can freeze, causing a blockage of the expansion valve.

Q5. The requirement for oil in the compressor is obvious, but why does it need to be circulating around the system?

A. All components are connected by either aluminum or rubber tubing, with each connection sealed by a rubber "O" ring. This "O" ring must remain moistened (expanded) by the oil to maintain the seal.

Q6. Why should the air conditioning system be run in the winter?

•  Air conditioning systems are also dehumidifiers. The atmosphere in winter generally contains more moisture and by using the air con system the windscreen will clear faster and carpets will dry faster. Running the system will also circulate the oil thereby keeping the seals tight and the compressor lubricated leading to a more efficient system. Most modern cars will automatically switch on the air-on system on selection of windscreen demist. (You can still have the heater on maximum heat while running the air con system).

Q7. Why do I get a musty smell inside the car?

This is caused when not all of the moisture on the evaporator drains off via the drain tube and contaminants, bacteria, mould etc, then become stuck on the evaporator. They in turn thrive in the damp dark warm atmosphere and spread. The treatment for this to use one of several available Anti-Bacterial sprays.

Q8. I have been advised to change my cabin air filter every 12000miles, why?

A. Pollution inside your car can be greater than in the air outside. A regular change of filter, will not only benefit the comfort of yourself and your passengers, but a blocked filter will put a strain on the fans and blowers in the system.