Refrigeration query

I note that considerable effort has been expended in creating an intelligent air-conditioning system for hybrid cars (News, 18 May).

I have, for many years, wondered why no one has, apparently, developed a refrigeration unit for air conditioning on conventionally engined cars that use the absorption refrigeration principle. These refrigerators are common fitment in caravans, using heat to evaporate the refrigerant.

Perhaps it has been tried but found wanting, but one thing is for sure: there is plenty of waste heat available for free in the internal-combustioned engined car to provide the energy. It would save a significant amount of energy as the pump used in the present system would not be needed.

I believe that Electrolux holds many of the patents for this system. Perhaps someone out there could tell us if it has been tried, and whether it worked.

Dave Draper