Understanding Thermal Expansion Valves in HVAC Systems

At Milwaukie Heating & Cooling, we believe that knowledge is power when it comes to your home’s comfort systems. Today, we’re diving into the technical details of a crucial component in many air conditioning units: the thermal expansion valve (TXV).

What is a Thermal Expansion Valve?

A thermal expansion valve is a metering device used in air conditioning and refrigeration systems. Its primary function is to regulate the flow of refrigerant into the evaporator, ensuring optimal system performance and efficiency.

How Does a TXV Work?

The TXV operates based on three main principles:

1. Temperature sensing
2. Pressure regulation
3. Spring tension

The valve contains a temperature-sensing bulb filled with a similar refrigerant to that used in the system. This bulb is attached to the outlet of the evaporator and responds to temperature changes.

The Technical Process

1. As the evaporator temperature rises, the refrigerant in the sensing bulb expands.
2. This expansion increases pressure on the diaphragm inside the valve.
3. The diaphragm pushes down on the spring, opening the valve further.
4. More refrigerant flows into the evaporator, cooling it down.
5. As the evaporator cools, the process reverses, reducing refrigerant flow.

This continuous adjustment ensures that the evaporator maintains optimal efficiency, regardless of changing conditions.

Benefits of TXVs in HVAC Systems

• Improved system efficiency
• Better temperature control
• Longer compressor life
• Adaptability to varying load conditions

Understanding these technical aspects helps our team at Milwaukie Heating & Cooling provide top-notch HVAC services to our clients in Clackamas, Happy Valley, and West Linn, OR. Whether you need installation, maintenance, or repairs, our technicians are well-versed in the intricacies of HVAC systems, ensuring your comfort year-round.