What is a Thermostatic Expansion Valve?
Does your air conditioner use a thermostatic expansion valve? Common in HVAC or refrigerant systems, it is a passive, regulatory feature that’s meant to keep a room or ice box within a set temperature range. It helps to control the flow of refrigerant into the evaporating coils within your home’s air conditioning systems. Knowing if your home has one can help with understanding maintenance and repairs.
Understanding the Basics
The benefit of a thermostatic expansion valve is that it is robust and may be used for years without needing adjustments. However, it is not the most precise way of measuring because it takes time for the spring, which is sensitive to temperature and air pressure, to open and close. It uses a copper sensor to determine the rough temperature inside an environment and releases refrigerant if the springs controlling the valve are too hot. Other devices are needed to help regulate the thermostatic expansion valve for a specific temperature. It is perfect for refrigerators and as a rough sensor, and is essential for heat pumps to sense the ground and room temperatures.
Types of Thermostatic Expansion Valves
There are several types of thermostatic expansion valves. The type used depends on the refrigerant being regulated, the system it’s installed in, and where the heat source is coming from. A standard valve receives temperature input from both the environment and the refrigeration coil. A balance is achieved between these two forces, and a standard TXV valve is used to conserve electricity and wear on the compressor. Some sensors like this only take a reading from the end of the condenser and shut down the system if there is a mechanical problem.
The Role of the Valve in HVAC Systems
The advantage and necessity of the thermostatic expansion valve is that it works independently of any electronic control mechanism. The most important thing is that a refrigerated device does not burn out and release refrigerant due to a malfunction, such as the power going out or the air getting too hot. The device senses pressure more than a precise temperature reading, and the goal is to halt the loop if the refrigerant is too cold or depressurized.
Installation and Maintenance Best Practices
The thermostatic expansion valve is essential for a heat pump's function. Many houses use a refrigeration loop that travels several feet underground to save on heating and cooling costs. The great thing about ground temperature is that it is much warmer than outdoor temperature in winter and cooler in summer. The ground around the heat pump line stores heat and cold to be recycled as the seasons flip. The goal is to monitor the temperature underground, which the thermostatic expansion valve does by sensing pressure. A specialized TXV device allows for more reliable readings.
Common Issues and Troubleshooting
All maintenance involving direct exposure to the refrigeration line has to be performed by a licensed specialist. When an HVAC specialist comes to inspect the air conditioner, they may look at the refrigerant pressure and compare temperatures from the thermostat to direct readings. Experts can usually tell if a device is not working properly from these readings. Not all HVAC units have electronic sensors that confirm if the thermostatic expansion valve is working properly.
A technician will usually start by replacing the refrigerant in the appropriate volume. If that does not solve the issue, they might also replace the TXV, although that is rare because the thermostatic expansion valve is known for being robust. These devices are more reliable than electronic sensors and might be preferable because of their longevity.
Thermostatic expansion valves are used commonly across all corners of the HVAC and refrigerant industry. Until recently, there had been no alternatives that were as reliable or powerful. However, recently electronic regulatory devices have become more common, although they still lack the lifespan of their analog equivalents. In the future, hybrid devices are expected to become more common.
Thermostatic Expansion valves are a valuable asset to your home or office HVAC system. If you encounter any problems or have concerns, contact Ardmore Fresh Air. Our expert team can assist you!
