What makes Car air conditioning work?

An automotive air conditioning system can be classified into four basic parts - a belt driven pump called a compressor to compress and circulate gas, a radiator like unit called a condenser (releases heat and condenses gas to a liquid), an expansion device, either a thermal expansion valve (TXV) or an orifice tube (depending on the kind of air-con 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 vehicle air conditioning system is designed to pull heat from the air within the inside of the car and transfer it to the exterior, leaving only cooled or 'conditioned' air behind to be redistributed. 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 conditioning service involve?

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

• Test air vent temperature

• Make sure condenser temperature is correct
  
  
• Evaluate suction line temperature
  
  
• Pulley and drive belt adjusted
  
  
• Operational check of valves and thermostats
  
  
• Validate cleanliness of the condenser fins
  
  
• Ensure good condition of components and hoses
  
  
• Evacuation and recharge of refrigerant (where required)
  
  
• Use electronic leak detector to test system lines and components for leaks

Why do I need a car air conditioner system service?

Preventing compressor seizure is achieved by checking or changing the oil level in the refrigerant. If the air filters become obstructed with dirt and bacteria it will affect the performance of the entire system and it can even cause it to cease functioning altogether. As well as reducing air conditioner performance, dirty air filters can cause all kinds of health problems too.

A vehicle air conditioner ought to be checked for problems annually for any signs of problems with the seals, hoses and connections to ensure refrigerant levels have not diminished over time. Regular service of your automotive 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 minimises fuel expenditure.

Why does the car air conditioner need to be serviced?

A vehicle air conditioning system is designed to pull heat from the air within the inside of the car to the exterior, leaving only cooled or 'conditioned' air behind to be redistributed. 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 mercy of the elements and very difficult operating conditions and being expected to function occasionally rather than being 'Always On' can have a detrimental effect on the hoses, connections and seals. An air conditioning system 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 causing the bad smell in car air conditioners?

The moist environment can support the development of microbes, bacteria and even fungus growth inside the evaporator core. This can lead to nasty smells and possibly even be bad for the health of any vehicle occupants. Newer type evaporator units tend to be more efficient, but more fins equals increased capability to trap moisture and allow for micro-organism development.

Brisbane Valley Mechanical mechanics have access to specialised ultrasonic technology to take care of any micro-organisms that may cause unpleasant odours 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.