A three-in-one device is provided, which incorporates functions of a 
water heater, a water dispenser and a cabinet-type air conditioner. The device is implemented by connecting three water-storage condensation heater exchangers in series at the heat-radiating end of a compressor, cooling a condenser via the cold energy in the low-temperature water to improve the power of a refrigerator by 50%. During the process of cooling the refrigerator, the heat produced by the air conditioner is used as a heat source for the 
water heater and the water dispenser, and the heat can be heated to a 
moderate temperature of 50 DEG C and a high temperature of 80 DEG C to substitute the 
water heater. The water flowing out of a front faucet of a cabinet is treated by a filter and then is used as 
purified water to substitute the water dispenser. The device is in 
closed circuit and in pressure state to give no chance for 
epidemic spread and terrorist empoison. An air inlet is provided on the top of the device, and an 
air filter is arranged inside the air inlet. The air is filtered and then discharged, so as to refresh the air. The device realizes the 
refrigeration, heat 
radiation and 
heat consumption, keeps the balance between the heat and the cold, and makes full use of the 
waste heat to reduce the consumption of 
heat supply resources by 60% and water 10%. The device serves as an air conditioner without outdoor unit and heat 
discharge, and is the environment-friendly, perfect and ideal device with easy use.