Advantages and disadvantages of direct heating heat pump water heater?
Another factor that affects integrated energy efficiency is the power consumption of pumps. Since the direct heating water flow is only 1/8, it is often directly driven by the tap water pressure. Therefore, the direct power consumption on the water pump is generally negligible compared with the direct heating type. While the pump power of the cycle is generally accounted for the heat pump mainframe power 5%- 10%, so virtually, air source heat pump of a 5P power consumption on water pump in about 250W-500W, virtually low comprehensive energy efficiency 0.19-0.36.
Comprehensive energy efficiency here, the comprehensive energy efficiency, mainly refers to two points, one is the heat pump unit itself energy efficiency, one is the water pump power consumption, in general, the heat pump input power is not included in the pump power. In general, the condensing pressure and condensing temperature of direct heating is relatively stable, the energy efficiency is relatively stable and easy to be measured, the circulating efficiency varies with the water temperature, the energy efficiency is not easy to measure. In the same configuration system, the average energy efficiency of the direct heating unit is higher than the cycle type 0.1-0.3
The advantages of a heat pump water heater 1) condenser stable regardless of water temperature and environmental temperature, water temperature constant when the heat, the condensing pressure and condensing temperature is nearly constant. We can use this characteristic to control the water temperature with a condensing pressure regulator. Compared to the cycle type, the direct heating type at least on the condensing side, the working condition is stable. This is critical for prolonging the service life of the compressor, and also affecting the frosting speed of the heat pump.
