| 摘要 |
A heating and cooling system is disclosed. The system is designed to selectively heat or cool room air and to allow the refrigerant to flow in one of first and second expansion valves, thus improving the thermal efficiency during a heating or cooling operation. During a cooling operation, the refrigerant flows in the order of the outdoor unit, the first expansion valve, the indoor unit, the first expansion valve, the compressor, and the outdoor unit. During a heating operation, the refrigerant flows in the order of the outdoor unit, the second expansion valve, the compressor, the indoor unit, the second expansion valve, and the outdoor unit. Each of the two expansion valves has a capillary tube encased by a case. The capillary tubes of the two expansion valves have different diameters. |
