4 way valve working :
A 4-way valve plays a crucial role in the operation of a heat pump or air conditioning system, specifically in systems that use a refrigerant to transfer heat. This valve is often referred to as a reversing valve because it reverses the flow direction of the refrigerant in the system, allowing it to switch between heating and cooling modes. Here’s how a 4-way valve works in an air conditioner or heat pump:
- Cooling Mode:
- In cooling mode, the 4-way valve is in one position.
- Hot refrigerant gas from the compressor enters the valve.
- The valve directs the refrigerant through the outdoor coil (condenser coil), where it releases heat to the outside air. This process causes the refrigerant to condense into a high-pressure, high-temperature liquid.
- The liquid refrigerant then flows through the expansion valve, where it undergoes a sudden drop in pressure and temperature, becoming a cold liquid-gas mixture.
- This cold refrigerant flows into the indoor coil (evaporator coil), where it absorbs heat from the indoor air.
- As the refrigerant absorbs heat, it evaporates into a low-pressure gas.
- The 4-way valve ensures that the refrigerant flows in the correct direction for cooling, with the evaporator coil being the heat-absorbing component.
- Heating Mode:
- In heating mode, the 4-way valve is in the opposite position compared to cooling mode.
- Hot refrigerant gas from the compressor still enters the valve, but now it’s directed through the indoor coil (evaporator coil).
- The cold outdoor air is the heat source in heating mode. The refrigerant in the indoor coil absorbs heat from the air and evaporates.
- The now-warm refrigerant gas flows to the outdoor coil (condenser coil), where it releases heat to the outside air.
- This heat exchange process allows the refrigerant to release heat indoors.
- The 4-way valve ensures that the refrigerant flows in the correct direction for heating, with the evaporator coil being the heat-absorbing component and the condenser coil being the heat-releasing component.
In summary, the 4-way valve in an air conditioner or heat pump is responsible for reversing the flow of refrigerant between the indoor and outdoor coils, depending on whether the system is in cooling or heating mode. This reversal of refrigerant flow allows the system to provide both cooling and heating functions efficiently.
Diagram of outdoor wiring with 4 way valve