In heat pump systems, which valve is used to switch from heating to cooling?

In heat pump systems, which valve is used to switch from heating to cooling?

• A. Solenoid valve
• B. Globe valve
• C. Check valve
• D. Reversing valve

Answer: (D)

A reversing valve is used to switch between heating and cooling in a heat pump by reversing the direction of the refrigerant flow. When the valve is energized, it changes the path so the indoor coil becomes the condenser and the outdoor coil becomes the evaporator, delivering heat inside and absorbing it from outside. In cooling mode, the flow path is reversed back so the outdoor coil acts as the condenser and the indoor coil as the evaporator, removing heat from indoors. The other valves don’t switch the system’s direction of flow; a globe valve throttles or regulates flow, a check valve prevents backflow in one direction, and a solenoid valve controls flow in a single circuit. Only the reversing valve is designed to reverse the refrigerant circuit, enabling the two modes.

A reversing valve is used to switch between heating and cooling in a heat pump by reversing the direction of the refrigerant flow. When the valve is energized, it changes the path so the indoor coil becomes the condenser and the outdoor coil becomes the evaporator, delivering heat inside and absorbing it from outside. In cooling mode, the flow path is reversed back so the outdoor coil acts as the condenser and the indoor coil as the evaporator, removing heat from indoors. The other valves don’t switch the system’s direction of flow; a globe valve throttles or regulates flow, a check valve prevents backflow in one direction, and a solenoid valve controls flow in a single circuit. Only the reversing valve is designed to reverse the refrigerant circuit, enabling the two modes.