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 several relatively warm years (and 2006 being the warmest year in the UK for over 300 years) the benefits of air-conditioning are gradually being generally accepted.
Moreover the additional benefits that are not immediately obvious are now being appreciated by those fortunate enough to have a good air conditioninng system operating in their car.
So what are the 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.
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.
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. Very few cars are not able to utilize this extremely useful facility.
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 becoming 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.
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.
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.
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.
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.