AC Anatomy: Thermal Expansion Valve

AC Anatomy: Thermal Expansion Valve

As a homeowner, it’s important that you know and understand the functions of the different parts of your AC. Even if you’re not planning on fixing it yourself, knowing the lingo can help keep you comfortable and save you money. For this AC Anatomy lesson, we’ll be covering the expansion valve. It’s a little, but vital part of your of your home’s comfort system. Find how this little part makes a big difference in your air conditioner.

What Is a Thermal Expansion Valve?

The thermal expansion valve (TXV) is an important part of your air conditioners refrigeration process. Your HVAC system cools your home using liquid refrigerant. The TXV controls the amount of refrigerant that goes into the evaporator. It regulates the amount this by matching the flow rate against the amount of refrigerant that evaporates in the coils.

The thermal expansion valve does this by measuring two variables, the temperature of the refrigerant vapor and the pressure in the evaporator. A movable valve pin is used to control the amount of refrigerant that flows to the evaporator.

Signs There Is a Problem With Your Thermal Expansion Valve

Since the TXV is such a vital part of your system, problems with it can cause numerous problems with your air conditioner. Here are just some of the signs that something might be wrong with your TXV

  • Noisy System. If you hear a lot of clanging, squealing or screeching coming from your AC, it may be a bad TXV. You should have a professional come and look at your unit to see if the TXV is the noisy culprit.
  • Frozen Coils. As you now know, the TXV is an important part of the refrigeration process. If it is broken or faulty then it may not cut off. This allows the liquid Freon to move freely from the to the metal coils, causing them to freeze.
  • AC Doesn’t Shut Off. Air conditioners are designed to shut off when they reach a certain internal temperature. If the TXV is broken, they may never reach this temperature and your AC will be running continuously.

Your Trusted AC Professionals

If you are experiencing problems with your air conditioner, then call Engineered Air today. Our experienced technicians can help diagnose, repair and install all types of AC units. Don’t wait; find out how Engineered Air can keep your home feeling great year-round!