HomeBLOGAir ConditionersWhat Is a Two-Stage Air Conditioner?

What Is a Two-Stage Air Conditioner?

You probably saw the term “two-stage system” on a brochure while looking for a new air conditioning unit and wondered.

A two-stage air conditioner uses a compressor to operate at two levels to meet your cooling needs more efficiently.

Let’s explore its features to determine if it is a better choice than a more affordable one-stage AC Unit. 

What Is a Two-Stage Air Conditioner?

An AC unit with a two-stage compressor will work at 100% capacity to cool your room on intensely hot days. 

For instance, it’s 95 degrees outside, and you want to keep your room at 74°F. In this case, a two-stage air conditioner will work at total capacity to maintain a 74°F temperature within your home.

During spring, when the temperature outside is around 85°F, the AC unit will operate at 60% to 70% capacity to achieve and sustain 74°F indoor temperature. 

Differences Between One-Stage and Two-Stage Air Conditioners

The difference between one-stage and two-stage air conditioners is how their compressors work

A one-stage, or “single-stage,” air conditioner runs at full blast regardless of the outdoor temperature. But once the desired temperature is reached, the AC unit will shut off. Then, it switches on when the indoor temperature increases. 

Without the option to operate at a lower capacity, the one-stage air conditioning system consumes more energy and undergoes frequent on-and-off cycles. 

Besides increasing your electric bill during summer, it causes the indoor temperature fluctuates more often.

Most homeowners are concerned about energy efficiency, comfort, and cost savings, so the two-stage AC units are the better option. But here’s the catch: They are $500 to $1000 more expensive than one-stage systems in terms of the initial cost. 

Benefits of Two-Stage Cooling

Greater energy efficiency, more significant savings

Greater energy efficiency, greater savings

Since a two-stage system can operate in two modes, your AC unit will run at full capacity only during intensely hot summer days. It operates in partial capacity for the rest of the year, saving you money on utility bills.

Many homeowners consider its pricy upfront cost as a long-term investment. 

Consistent comfort

With the ability to change from high to low capacity, the AC unit does not have to switch off as often as the one-stage unit. This enables it to run longer and provide a consistent cooling output.

Better at controlling humidity

Humidity can make the temperature feel hotter. A temperature of 85°F can feel a lot warmer if the air is humid, or more specifically, if you live close to warm bodies of sea.

Having a two-stage system will help in managing humidity in your home. Because it operates without frequently switching on and on, it has more time to remove vapor from the air.  

Example of a Two-Stage Air Conditioner

So, which AC units utilize two-stage systems? Let me share some examples to give you a better idea of the options available in the market.  

Carrier Infinity 21 Central Air Conditioner

Carrier Infinity 21 Central Air Conditioner

Considered Carrier’s high-end product, the Infinity is expensive when you look at its hefty price tag, installation cost, repairs, and maintenance. 

However, thanks to its energy-efficient system, you will save money throughout its life cycle even if you add up everything you spent, including your electric bill.

Moreover, the Infinity is relatively quiet. You’ll probably hear it hum, but it will not be as loud as your old unit. 

Goodman GVXC16 Air Conditioner

Goodman GVXC16 Air Conditioner

Among Goodman’s more advanced models, the GVXC16 is surprisingly more affordable than I thought. Its two-stage compressor and two-stage fan powering unit work hand-in-hand to keep things cool at home.

But what I like about this model the most is that it has a diagnostic system via an app to aid technicians in determining issues right away. 

Trane XL 18i Air Conditioner

Trane XL 18i Air Conditioner

Another popular choice is the Trane XL 18i. With a high energy efficiency rating, you can depend on it to distribute cool air evenly throughout your home. Even when you switch it on an entire day during summer, you can expect it to keep your electric bill low. 

What sets it apart from other models is its Weatherguard top that prevents the debris and elements from entering the AC unit.

People Also Ask

Which is a better single-stage or two-stage air conditioner?

Features alone do not dictate our choices. We also think about the budget and the size of the space that needs air conditioning.

While a two-stage air conditioner has a more energy-efficient system, it does not mean that the one-stage air conditioner is an “inferior” choice. 

If you’re working with a tight budget, opting for one-stage systems will make more sense. Besides, the low upfront cost is not the only advantage it offers. 

When it comes to repairs, you can count on single-stage compressors that can be fixed with universal, readily available parts. Plus, they can cool smaller houses sufficiently. 

Meanwhile, two-stage systems are better suited for two-story or split-level homes where certain rooms may be hotter than the others. Also, they are great money-savers if you factor in all the bills you will have to pay in the next decade. 

Many homeowners do shy away from their expensive units and installation costs. Another downside to the two-stage systems is that they have specialized parts that can take up to 10 business days to get from the manufacturer. 

Two-stage air conditioners are durable, and you can lengthen their lifespan with regular maintenance. When you think about it, the chances of your unit breaking down are pretty low.

Is a 2-stage air conditioner worth it?

Yes. If budget is not a concern, I highly recommend getting the 2-stage air conditioner. 

Ask any HVAC service provider, and they will tell you that any 2-stage air conditioner would be a better choice than a 1-stage air conditioner. 

As explained in this article, the two-stage system proves to be more energy efficient. More importantly, it can sustain a comfortable room temperature and reduce humidity. 

It will probably take a while before you see a “return on investment,” but you will see significant savings. 


Now that you’ve seen all the pros and cons, you will not regret investing in a two-stage air conditioning system. 

Still, other factors will also determine our choices. Budget constraints, for instance, can make us think twice about getting an AC unit with far more sophisticated technology.  

When in doubt, you can always ask your local HVAC service providers to point you in the right direction to make a more informed decision.

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