a conversion unit for an air conditioning system to cause it to act like the cooling unit of a refrigeration system comprises a frost detector , an a / c temperature control defeating mechanism and a control unit which operate together to force the range of operation of the air conditioning unit into the range of operation of a refrigeration unit . the conversion unit is particularly useful for providing low cost cooling systems for farmers in third world countries for keeping their produce fresh and safe , not to mention its use by all farmers around the world and by florists or others in need or desire of an economical refrigeration alternative . the present invention is also usable to provide inexpensive cooling to rv &# 39 ; s and to refrigerated vehicles .