ROCKETING demand for air conditioning could lead to unexpected costs for fleet operators wanting to keep their employees cool. The warning comes after a number of cases of fleet managers picking up the bill for costly repairs to damaged air conditioning units which were not covered by manufacturer warranties.

Industry forecasts expect almost 60% of new cars to be fitted with air conditioning as standard by 2000 - up from 26.31% in 1990 and an estimated 46% last year. Most manufacturer warranties cover factory-fitted air conditioning units, but these policies don't extend to accidental damage - caused, for example, by flying stones.

Martin Morris of IT Matters was presented with a bill for £400 after the air conditioning unit in his P-registered Volvo S40 failed after just 10,000 miles. The dealership attributed the problem to a condenser which had been punctured by a stone and was not covered by the warranty.

A Volvo spokesman said: 'While all Volvos enjoy the benefit of a three-year/60,000-mile warranty, this warranty does not cover accidental damage. We recommend Mr Morris makes a claim against his insurance policy, which should cover him for this type of damageWe have passed on the details of this incident to the factory for their information.'