How to Properly Dispose of an Old Air Conditioner. Air conditioners, regardless of type, all contain some form of cooling refrigerant.According to the Environmental Protection Agency, many window air-conditioning units, and dehumidifiers contain hydrochlorofluorocarbon 200 (HCFC) refrigerant, an ozone-depleting substance (ODS) that, if released to the environment, can destroy the ozone layer.