How Does an Air Conditioner Expansion Valve Work?

Homeowners everywhere love their air conditioners, but many don't understand how they work or what parts they rely on to function. Air conditioner expansion valves, in particular, are a mystery to many people.

Our team at Premier Systems is here to answer the question, "How does an air conditioner expansion valve work?" After reading this guide, you'll learn about this part, why it matters, and how much it costs to replace it.

If you need reliable AC repair service in Bozeman, call us at (406) 629-1583.

What Is an Air Conditioner Expansion Valve?

Air conditioners rely on refrigerant to complete the refrigeration cycle. This refrigerant absorbs heat from air and then turns into a high-pressure gas before returning to a liquid form. All of this depends on the right pressure levels.

The air conditioner expansion valve is a small yet vital component that controls unit pressure. It channels the right flow of refrigerant — a rather small amount — into the evaporator coils, preventing an improper increase in pressure. As the flow of refrigerant shifts from the compressor to the evaporator, the air conditioner expansion valve subtly recalibrates itself as needed to achieve efficient refrigerant distribution.

Are All Air Conditioner Expansion Valves Thermostatic Valves?

When asking, "How does an air conditioner expansion valve work?" many homeowners assume that all air conditioner expansion valves are thermostatic valves. Thermostatic expansion valves are quite common, but they aren't the only type of valve.

There are four main types of air conditioner expansion valves: automatic expansion valves, capillary tubes, thermal expansion valves, and thermostatic expansion valves. The specific means of operating might vary from unit to unit, but the core principle is the same. They all control the flow of refrigerant from one part of the air conditioner unit to another.

Why Are Air Conditioner Expansion Valves Important?

Now that you understand the answer to the question, "How does an air conditioner expansion valve work?" you still might not know why these valves matter. Isn't there another way for the air conditioner to handle refrigerant flow? Why do modern air conditioners even need refrigerant?

Put simply, your air conditioner cannot work without an air conditioner expansion valve. Portable, window, and split-system units all use expansion valves to control the flow of refrigerant. By regulating the flow of refrigerant, they keep a steady level of pressure in your evaporator, preventing overheating and other complications.

Their other main function is to cool your unit's air supply. Refrigerant by itself can't handle air cooling; it needs space and the right pressure levels to move from a gas to a liquid and back again. In particular, as it shifts to a gas, it captures absorbed heat, making the air supply cool before your unit's fan circulates it throughout your home.

Cost of Replacing an Expansion Valve

It's important for homeowners to understand the costs of replacing an expansion valve. You can typically expect to pay about $400 for a standard valve body replacement job. If there are fewer or more problems at play, this range can shift between $200 and $700.

Working with the right HVAC contractors can also help you save money. By replacing your valve, you'll ensure proper unit functioning for many years to come, preventing future breakdowns that could cost you money. You might even want to invest in a central air conditioner for maximum energy efficiency and savings.

Identifying Expansion Valve Issues

Refrigerant should flow at a reasonable pace, but did you know that a bad expansion valve can cause a more frenetic flow rate? If you frequently hear whistling or squeaking noises, you could have a malfunctioning expansion valve.

Have you noticed a lack of cool air coming from your air conditioner? If so, there's a solid chance that your refrigerant valve is malfunctioning. Since these valves enable the cooling process by controlling the flow of refrigerant from place to place within a unit if they aren't working, that cooling process can't happen. 

Professional Air Conditioning Services in Bozeman

Premier Systems is your number one choice for air conditioner services in Bozeman, MT. We're highly skilled professionals with a proven track record and can help you repair or replace your expansion valves. If you want a more energy-efficient AC unit, we can help.



If you're still asking, "How does an air conditioner expansion valve work?" or if you want to schedule a consultation, call our Premier Systems team at (406) 629-1583. We can keep your air conditioner operating efficiently year-round.