How does a car air conditioner work?

An automotive air conditioning system is composed of four basic parts - a compressor (Pump driven by the engine,) which compresses and circulates refrigerant gas, a radiator like unit known as a condenser to remove heat and condense gas to a liquid, an expansion device, either an orifice tube or a thermal expansion valve (TXV) (dependent on the sort of air conditioner system used). Systems using orifice tubes also have an accumulator before the compressor to remove moisture from the refrigerant while TXV systems have a receiver-dryer before the evaporator to perform the same crucial task. Both the accumulator and receiver-drier are also used to store refrigerant.

A car air conditioning system is designed to extract heat from the air in the interior area of the car and transfer it to the exterior, leaving only cooled or 'conditioned' air to be recirculated. Hot air is passed across a gas filled evaporator, where the heat is easily absorbed by the refrigerant (in gas form), effectively removing the heat from the air in the car.

The now heated gas is pulled through the compressor where it is further heated (via compression). The next stage involves the refrigerant being forced through the condenser to quickly extract the heat from the refrigerant. The refrigerant, now condensed to a liquid, then moves through the expansion device (either a TXV or Orifice tube), which regulates the flow of refrigerant going to the evaporator, changing the high-pressure liquid to a low-pressure mist (gas). A fan blowing over the cold fins of the evaporator produces the cold air being blown into the car and the entire process then begins all over again.

What does a car air conditioner service usually consist of?

A typical air conditioner service may include some of the following items;

• Check air vent temperature

• ensure condenser temperature correct
  
  
• Suction line temperature check
  
  
• Drive belt and pulley adjusted
  
  
• Validate correct operation of valves and thermostats
  
  
• Check condenser fins are clean
  
  
• Check condition of components and hoses
  
  
• Evacuation and recharge of refrigerant (where required)
  
  
• Electronically check system lines and components for leaks

Why do I need a car air conditioner system service?

To prevent the compressor seizing the oil level in the refrigerant must be checked or changed. Should the air filters become clogged with dirt and bacteria it will affect the performance of the entire system and it can even cause it to cease working altogether. As well as reducing air conditioner performance, dirty air filters can cause all kinds of health problems too.

Your vehicle air conditioning system ought to be examined once a year for any signs of problems with the seals, hoses and connections and confirm too much regfrigerant is not being lost over time. Regular service of your vehicle air conditioner system keeps refrigerant at optimum levels meaning the system does not need to work as hard and this in turn protects the system from damage and reduces fuel expenditure.

Why does the car air conditioner need to be serviced?

A car air conditioning system is designed to extract heat from the air in the interior area of the car to the exterior, leaving only cooled or 'conditioned' air to be recirculated. This is achieved using a special compound called refrigerant, capable of readily absorbing heat as a gas and quickly losing heat as a liquid.

Being exposed to the elements and very extreme operating conditions and being expected to run intermittently rather than being 'Always On' can cause issues with the seals, hoses and connections. Your air conditioner should be examined on a regular basis to ensure there are no problems or refrigerant loss due to failure or leakage from these points.

Simply by cooling the air in your car under normal running conditions, the filters of the air con get dirty and intermittent use can cause seals to dry and crack, allowing them to leak. Even without leaks, the gas in a car air conditioning system will eventually begin to degrade or evaporate over time and should be recharged where required to keep the air con system in peak running condition.

Can I service my own air conditioner?

Only qualified mechanics with the appropriate training should attempt to service a car air conditioner. Specific licences are required to be able to service or repair some types of car air conditioning systems, especially where regas (recharging of the refrigerant) is concerned. Strict guidelines and procedures must be adhered to when handling certain refrigerants, which must always be fully recovered and not allowed to escape into the atmosphere during servicing.

Refrigerant can also pose serious health risks if handled incorrectly. Specialist equipment is also required as the air conditioning system is under extreme pressure and must be pulled into a deep vacuum to remove any moisture, to avoid seriously damaging the system. You can find out more about licensing on the Australian Refrigeration Council (ARC) Website.

What is the source of the bad smell in car air conditioning systems?

The damp environment inside the evaporator core can promote the development of bacteria, microbes and even fungus growth. This can lead to nasty smells and possibly even be bad for the health of any vehicle occupants. Although modern evaporator units tend to be more efficient, they have an increased capability to trap moisture and allow for micro-organism development.

Mr Spanner's Automotive mechanics have the capability to use specialist ultrasonic technology to ensure the removal of any micro-organisms that may be the source of bad smells or health concerns.

Just ask about our MIST service, which will kill any bacteria that may be lurking in your car’s air system. These bacteria can cause odours and even make you sick, especially if you have allergies or asthma. A MIST service doesn’t just make your car smell better - it makes it healthier for you and your family.