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The Cost Difference Between a Single-Stage and Two-Stage Air Conditioner

October 07, 2016

Updated February 2023

So your AC is dead (or close to dead) and you’re shopping for a new AC unit.

In your search, you’ve seen comparisons of single-stage vs. two-stage air conditioners. Now you’re wondering, “Is a two-stage AC worth the extra cost?”

Well, that depends why you want a two-stage air conditioner. Are you...

  • Trying to save money? Two-stage may not be worth it.
  • Trying to make your home more comfortable? Then buy a two-stage AC for sure.

We’ll explain both those points in more detail.

But first, we’d like to explain how a two-stage AC works, just to make sure we’re all on the same page here.

How a two-stage AC works

Here’s the cliffs notes version.

A single-stage AC only has one mode: High. Meaning your AC is running at full blast (full cooling capacity) whether you need that much cooling or not.

A two-stage AC, however, has a special compressor that can run on 2 modes:

  • High: Runs like a normal single-stage AC—full blast
  • Low: Uses less cooling capacity on milder days when you don’t need as much cooling

This “low” stage is the two-stage’s secret weapon. By running on this more energy efficient setting, you get these 2 benefits:

  • Lower your monthly energy bills
  • Provide better comfort (even cooling, better humidity control)

OK so are those benefits worth the extra upfront cost? Let’s talk about that.

Cost of Single-Stage vs Two-Stage AC

Trying to save money? Two-stage may not be worth it.

Can a two-stage AC lower your monthly bills? Sure. Will it save you enough to justify the higher upfront cost?


Consider this: Assume an HVAC company gave you price quotes on two AC units:

  • Single-stage: $4,600
  • Two-stage: $6,900

Note: These prices are for demonstrative purposes only. Your price will vary based on unit size and many other factors.

That’s a $2,300 difference. Given that an air conditioner lives about 10 years, the two-stage would need to save you $2,300 total over 10 years. Will it?

It might, given that two-stage air conditioners:

  • Live longer— Because two-stage air conditioners run all the time, they turn on and off less often, which reduces wear and tear on the compressor. A longer lifespan would mean the unit has more time to save you money.
  • Have more rebates— Two-stage ACs have higher SEER ratings (energy efficiency) meaning that they qualify for more rebates. For example, you can save up to $800 with SRP rebates for ACs with SEER ratings of 15 or higher.

Conclusion: Talk to your HVAC company about the lifetime savings of a two-stage vs. a single-stage. They can give you numbers while you’re getting a free in-home consultation.

Want more comfort? Buy a two-stage AC for sure.

Since the two-stage has a “Low” setting, it can run for longer periods of time. This longer runtime gives you two benefits:

  • More even cooling— By constantly circulating the air, your AC can cool your home more evenly. This means that it’ll get rid of annoying hotspots, like in your upstairs bedrooms or in rooms with lots of windows that get blasted by the sun.
  • Better humidity control— Your AC technically doubles as a dehumidifier. And the longer your AC runs, the more it can dehumidify your home. This isn’t a big benefit in AZ until monsoon season starts and the air becomes more humid and “sticky.”

Conclusion: If your heart’s desire is to live in a more comfortable home, then, yes, it’s worth buying a two-stage air conditioner.

Want to know the price of a two-stage air conditioner?

We'll send a comfort specialist out to your home to calculate the air conditioner size you need and then provide you a price quote.

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By Ty Lindsay

Ty Lindsay is the Director of Field Operations at Patrick Riley | Isley’s and a 15-year veteran of the plumbing and HVAC trades. In 2010, Ty earned his Journeyman’s plumbing license. He became a Master Plumber five years later and earned his Journeyman HVAC technician’s license that same year. Ty’s breadth of knowledge in plumbing and HVAC includes both residential and commercial work. He’s been a loyal member of the Patrick Riley | Isley’s team since 2016.