NOVELTY - A heat energy accumulator (7), a cooler (71), a solar collector panel (9A) and/or a car battery (9B) are integrated to a typical or existing car air conditioning system. The heat energy accumulator or the cooler stores a part of the cold energy produced by the system, before the refrigerant flows back to the compressor (1) in the system.    USE - For keeping indoor space of car at comfortable temperature even when typical car air conditioning system is turned OFF.    ADVANTAGE - Allows use of surplus cold energy produced by typical car air conditioning system to keep indoor space of car at comfortable temperature even when system is turned OFF. Enhances cooling effect. Allows cooler to function as spare car refrigerator, since cooler can also utilize part of cold energy.    DETAILED DESCRIPTION - The accumulator consists of an energy storage chamber and a loop type heat pipe. A phase change medium, which stores and releases the cold energy by freezing into and melting from a solid phase, is filled into the storage chamber. An insulator material coats the phase change medium to prevent heat loss. A lid at the top of the storage chamber allows phase change medium to be replenished into the chamber. A phase change medium drain hole is at the bottom of the storage chamber. The loop type heat pipe is divided into three sections. The first section has a set vertical parallel pipes disposed inside the storage chamber. Short fins, densely distributed on the outer surface of each parallel pipe, run perpendicular to the pipes. The second section includes a vertical low temperature heat pipe and vertical high temperature heat pipe both arranged outside the storage chamber. Fins or helically grooved tubes are provided on inner and outer surfaces of each heat pipe. The third section has upper and lower horizontal pipes connected between the parallel pipes and high and low temperature heat pipes. A working fluid e.g. freon, water, is circulated in the loop type heat pipe. A pressure limiting safety compartment, located outside the storage chamber, is connectable to the low temperature heat pipe. Low and high temperature heat exchangers, externally coated with the insulation materials, are arrayed outside the low and high temperature heat pipes.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic diagram of a natural air conditioning system.    Compressor (1)    Heat energy accumulator (7)    Solar collector panel (9A)    Car battery (9B)    Cooler (71)