In high efficient heat pump systems using R-410A refrigerant, what metering devices are typically used?

In high-efficiency heat pump systems using R-410A refrigerant, the choice of metering devices is crucial for maximizing the efficiency of both heating and cooling modes. The use of a fixed orifice in the heating mode allows for a straightforward and cost-effective way to control the flow of refrigerant, as it operates effectively with the consistent load typically found in heat pump heating applications. During the cooling mode, using a thermal expansion valve (TXV) is advantageous because it provides variable flow based on the load, optimizing the system performance and adapting to changing conditions within the evaporator. This combination ensures that the system operates efficiently across both heating and cooling modes by tailoring the refrigerant flow to the demands of the system.