Today, as we drive our automobiles, a
great many of us, can enjoy the same comfort levels that we are accustomed to at
home and at work. With the push of a button or the slide of a lever, we make the
seamless transition from heating to cooling and back again without ever
wondering how this change occurs. That is, unless something goes awry.
Since the advent of the automotive air
conditioning system in the 1940's, many things have undergone extensive change.
Improvements, such as computerized automatic temperature control (which allow
you to set the desired temperature and have the system adjust automatically) and
improvements to overall durability, have added complexity to today's modern air
conditioning system. Unfortunately, the days of "do-it-yourself" repair to these
systems, is almost a thing of the past.
To add to the complications, we now have
tough environmental regulations that govern the very simplest of tasks, such as
recharging the system with refrigerant R12 commonly referred to as Freon® (Freon
is the trade name for the refrigerant R-12, that was manufactured by DuPont).
Extensive scientific studies have proven the damaging effects of this
refrigerant to our ozone layer, and its manufacture has been banned by the U.S.
and many other countries that have joined together to sign the Montreal
Protocol, a landmark agreement that was introduced in the 1980's to limit the
production and use of chemicals known to deplete the ozone layer.
Now more than ever, your auto mechanic
is at the mercy of this new environmental legislation. Not only is he required
to be certified to purchase refrigerant and repair your air conditioner, his
shop must also incur the cost of purchasing expensive dedicated equipment that
insures the capture of these ozone depleting chemicals, should the system be
opened up for repair. Simply put, if your mechanic has to spend more to repair
your vehicle - he will have to charge you more. Basic knowledge of your air
conditioning system is important, as this will allow you to make a more informed
decision on your repair options.
Should a major problem arise from your
air conditioner, you may encounter new terminology. Words like "retrofit" and
"alternative refrigerant" are now in your mechanics glossary. You may be given
an option of "retrofitting", as opposed to merely repairing and recharging with
Freon. Retrofitting involves making the necessary changes to your system, which
will allow it to use the new industry accepted, "environmentally friendly"
refrigerant, R-134a. This new refrigerant has a higher operating pressure,
therefore, your system, dependant on age, may require larger or more robust
parts to counter its inherent high pressure characteristics. This, in some
cases, will add significantly to the final cost of the repair. And if not
performed properly, may reduce cooling efficiency which equates to higher
operating costs and reduced comfort.
Vehicles are found to have primarily
three different types of air conditioning systems. While each of the three types
differ, the concept and design are very similar to one another. The most common
components which make up these automotive systems are the following:
COMPRESSOR,
CONDENSER,
EVAPORATOR, ORIFICE TUBE,
THERMAL EXPANSION VALVE , RECEIVER-DRIER,
ACCUMULATOR.
Note: if your car has an Orifice tube, it will
not have a Thermal Expansion Valve as these two devices serve the same purpose.
Also, you will either have a Receiver-Dryer or an Accumulator, but not both.
For more information on Air
Conditioning, check out The Automotive Air Conditioning Information Server