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Different types of expansion valves used in AC

One hand adjust thermostat valve close up

In air conditioner systems, the expansion valves are the devices that are used to control the flow of the refrigerant. To have your existing expansion valve serviced, contact

Expansion valves control the amount of refrigerant allowed into the evaporator and maintain the pressure differential between the high-pressure condenser and the low-pressure evaporator. In this article we will discuss different types of expansion valves used in air conditioners. For more information, pay a visit to marvellous.  

Thermal expansion valve: 

A thermal expansion valve, is an essential part of any cooling or air-conditioning system. Mainly, it controls how much refrigerant flows into the evaporator coil, which affects how cold or warm the air is. This valve plays a crucial role in keeping the system at the right temperature. Whenever the temperature of a material (in this case, the refrigerant) varies, the substance will undergo a phase transition, and this is the basis for how a thermal expansion valve works. The valve has a small opening through which the refrigerant must pass.

The pressure and flow rate through the valve drop as the refrigerant expands when its temperature rises. On the other hand, decreased temperatures lead to higher pressure and flow due to the refrigerant’s contraction. They have become well-known due to the ease with which they may be accessed, the simplicity of their regulation, as well as their great sensitivity and precision. There is a vast selection in thermal expansion valves available on the market today, each one covering a different capacity and temperature range. 

Manual valves: 

Manual expansion valves serve a crucial function in controlling the amount of refrigerant that flows through air conditioning systems. You can modify the system’s cooling or heating potential by adjusting these valves, which regulate the flow of refrigerant into the evaporator coil. Many cooling and refrigeration systems rely on manual expansion valves to maintain tight control over the refrigeration cycle.

Manual expansion valves are used to regulate the flow of hot, high-pressure liquid refrigerant from the condenser to the cooler, lower-pressure evaporator coil. In order for the refrigerant to take in heat from its surroundings (as in air conditioning), the pressure must drop from high to low. To do this, manual expansion valves produce a pressure decrease in the refrigerant, causing it to rapidly expand and so lowering the temperature significantly.

Automatic valves: 

AEVs function independently of any external control mechanisms, making them superior to more conventional mechanical expansion valves. They provide a number of benefits, including better system efficiency and temperature regulation.

The primary purpose of an AEV is to keep the superheat at the evaporator’s outlet at a constant value. If the superheat is high enough, then the refrigerant will be completely vaporized before it leaves the evaporator. Superheat can be controlled with AEVs, which protect the compressor from damage and inefficiency caused by liquid refrigerant entering the system.

Automatic evaporation controls (AEVs) rely on a temperature-sensing bulb or capillary tube installed at the evaporator’s outlet. The superheat is monitored by this sensor, and the AEV controls the valve opening to keep things at the right temperature. Improved stability and efficiency in cooling and heating operations are the outcome of this dynamic regulation.

Electric expansion valves:

Modern air conditioning systems rely heavily on electric expansion valves (EEVs) to control the amount of refrigerant circulating through the system. EEVs provide accurate and dynamic control over the refrigerant flow, as opposed to the static control provided by mechanical expansion valves. This has positive effects on energy efficiency, temperature regulation, and system performance.

The valve opening in EEVs is controlled by an electric actuator that receives data in real time from several sensors. The EEV receives continual updates from the sensors on environmental conditions such as temperature, pressure, and superheat. The valve can optimize the cooling or heating process based on the current conditions thanks to its dynamic control.

Float valves:

Air conditioning and refrigeration systems rely heavily on float expansion valves. Its major purpose is to control the amount of refrigerant going into the evaporator coil, hence maximizing cooling and comfort. A float expansion valve works by keeping the evaporator’s superheat at a steady state. The valve maintains evaporator activity and prevents frost buildup and wasteful cooling by maintaining a continuous superheat.

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