Used SKM window air conditioner, clean (18,000 BTU / 1.5 ton) - used for one year only For sale: SKM window air conditioner Condition: Excellent, clean, and working with high efficiency. Used for one year only. Cooling capacity: 17,500 BTU (known as 18,000 BTU or 1.5 ton). Manufacturer: SKM (original compressor and refrigerant, never serviced). Energy efficiency: Standard for window air conditioners (Class W / F). The air conditioner has excellent cooling and has been well-maintained. It has been fully cleaned and is ready for immediate pickup and use.