General info and advantages
Because the UK has a temperate climate many people have assumed that air-conditioning in their car would be a rarely used luxury that was not worth paying for. Now that we have experienced a relatively warm summer (and 2013 being the warmest summer in the UK for over 10 years) the benefits of air-conditioning are gradually being generally accepted particularly as our climate is relatively damp with moist (and thus uncomfortable) air. Moreover the additional benefits that are not immediately obvious are now being appreciated by those fortunate to have a good system operating in their car. As over 90% of all new cars are now fitted with AC as standard since about 2012 almost all of us now have the ability to use this facility even if we only ever buy secondhand cars. Just be aware though that if you buy a two year old car that the AC will not be working as well as it was when it was new - most cars would be needing an AC service by three or four years old.
What are these benefits?
• The ability to reduce the in-car temperature to a comfortable
level on exceedingly hot days, without having a seventy mile an hour gale
buffeting you and being unable to hear the radio or your passengers because
of the wind-noise.
• If you have youngish children you will quickly appreciate the
extra quiet in the back – aircon seems to almost magically remove
the bad temper from most children.
• As aircon also conditions the air, the ability to remove the moisture
from the air coming into the car on really muggy days and to achieve a
comfortable atmosphere within the car, perhaps in conjunction with the
heater control - the AC button will control the Relative Humidity and
the heater if needed will control the temperature leaving you free to
enjoy the warmth without being stuffy.
• The ability to be able to see through the windscreen and all the
other glass clearly without a film of mist. The safety aspect of aircon
is often overlooked but is extremely important, particularly to the people-carriers
which are so popular now. Using the AC button to direct the air to the
screen the moisture on the glass will be evaporated very rapidly, long
before a screen-heater has had a chance to warm up and will continue this
advantage around the side glasses and on to the rear screen. For best
effect use the AC button, perhaps in conjunction with the heater in winter
and on the fresh air setting (not recirculation). AC is usually extremely
good at de-misting and this safety aspect of good all round visibility,
even when picking up a crowd of wet noisy kids in winter, is one of AC's
strong points. It has to be admitted that very occasionally the climate
can be so very damp on odd days that even with the AC working effectively
the demisting function can work only slowly but this is very much in the
minority - for most days the AC will clear the screen almost like magic.
• The cleaner, fresher air with low Relative Humidity will enhance
driver awareness and help prevent drowsiness making your journeys and
those of your loved ones safer over long distances as drivers are better
able to remain fresh and alert.
• Being caught in a long traffic jam on a hot day can be purgatory
with all the exhaust fumes coming straight into your open windows, particularly
if you are dressed for business - wet under the arms and hot under the
collar - probably the time when you most wished that you had bought a
car with aircon. This is when AC proves it is one of the nicest affordable
luxuries.
• All the air coming into a car with aircon passes through a heat-exchanger,
which as it is very cold, quickly becomes dripping with condensation,
which collects and drains out under the car. Air entering this heat exchanger
will contain dust and pollen grains, but by the time the air has passed
through this heat-exchanger (called the evaporator) the vast majority
of these pollutants will have been filtered out, trapped by the condensate
and dripped back onto the road. It is estimated that approximately 80%
of all dust and pollen is trapped in this way on each pass through the
evaporator - this helps us all but is a source of particular relief to
Hay Fever sufferers or Asthmatics, particularly children. Most modern
cars now also include a filter to remove most pollen and dust, although
frequently called a Pollen Filter it should really be called a Cabin Filter
as it is very useful in both summer when pollen is rife and in the rest
of the year to remove road dirt and other pollutants such as brake and
tyre dust. The AC will simply assist the removal of these pollutants.
• By allowing all car windows to remain closed, even on the hottest
days, the aerodynamics of the car remain at optimum, keeping fuel consumption
low and exterior noise to a minimum, increasing safety to the driver and
passengers. There is a page devoted to the fuel consumption aspect of
AC - please read this as there are plenty of urban myths on the use of
AC. Tell any lie frequently enough and many people will start to believe
it.
Any disadvantages? A couple of minor ones - Opera singers or even actors can find that the dry air can degrade their voice.
Slightly more common though are the wearers of contact lens who may find after some hours in the very dry air that their lens can dry slightly and make the eyes feel uncomfortable.
More important though is the effect on fuel consumption IF THE CAR IS USED ONLY ON SHORT, LOCAL JOURNEYS. On all other journeys over say 15 minutes, especially if used on fast roads, the effect on fuel consumption of using the air conditioning is minimal and it is usually more economical to turn on the AC than it would be to open a window. There is a whole page a lttle futher on in this website devoted to the subject of fuel consumption whilst using AC.
Good though Air conditioning is it was not even invented for use with people but was developed for drying paper.
To reproduce colour pictures, printers print one colour at a time on each sheet of paper. One printing method very suitable for reproducing pictures is called lithography and involved printing from a large, flat, block of limestone which was dampened with a water roller before the ink was applied but when the paper came into contact with the limestone it absorbed some moisture from it causing the paper to expand. This made it impossible to print the next colour accurately until the paper had been dried and thus returned to the same physical size as when the previous colour had been printed. So just over a hundred years ago a system was invented and installed into a New York lithographers in order to remove moisture from the air and thus rapidly dry the sheets of paper.
So it was called Air Conditioning because it conditioned the air by the reduction of the moisture it contained. It is not just the cooling of the air which makes it so comfortable to people but it is the reduction of the moisture content and this is why it is just as important in the warm damp climate of the UK as in the hot but dry climate of central Spain.