Why does the maximum outlet temperature of an air source water heater only reach 60℃? This is the reason!The heating temperature of the air source water heater is determined by the state of the gaseous refrigerant (the commonly used R22 is taken as an example below) at the compressor outlet: pressure 1.5 Mpa, temperature 85°C (different heat pumps and refrigerants have different parameters). According to the law of conservation of energy, it can be seen that the heating temperature is generally impossible to exceed 85°C, so it cannot be simply considered as a substitute for the boiler.
Usually, the setting of 60°C for air source water heater is mainly to prevent the generation of scale. Generally, non-softened water is more prone to scaling when the temperature is above 60°C, which will cause scale to attach to the outside of the coil, which will affect the heat transfer efficiency of the fluorine cycle, or cause the water circulation equipment to be blocked and cannot be used, so 60°C is a standard line. However, the bath temperature in winter is generally 45-50℃, and 40℃ of hot water for daily kitchen life is sufficient.
At the same time, because of the pressure that the compressor and piping of the air source water heater can withstand, the higher the water temperature, the greater the work required by the compressor, the higher the exhaust temperature, and the greater the pressure that the compressor and piping can bear. The exhaust pipe has insufficient pressure resistance, and the pressure is too high and the pipe may burst easily! Therefore, in the electronic control design, generally only the upper temperature limit is set to 60 ℃ to protect the normal operation of the entire unit! If the temperature exceeds 60°C, or the exhaust temperature exceeds 110°C (generally set to 110°C), it will shut down automatically!
Remarks: 80 degrees Celsius of ultra-high temperature air source heat pump is not the limit, so it is not in the scope of this discussion