High-efficiencyprovide hot water at -25c with cop: 1.61) famous america copeland compressor; 2) america shall & tube high efficiency heat exchanger; 3) environment-friendly refrigerant r417a can be chosed. 4) powder coated cabinet for attractive and economical; 5) no potential hazards of inflammable, explosive, electric shock, gas poisoning; 6) saving cost as high as 60%80% compared with oil boiler, gas boiler, coal boiler, electricity water heater etc