Compared to single-stage ACs, 2-stage air conditioners provide better comfort at a lower cost (which means less expensive energy bills during the summer).
But those benefits come at a price—a 2-stage AC in Idaho typically costs $1,000–$2,500+ more than a single-stage AC.
So should you take the plunge on a 2-stage AC? Well, it depends…
- Are you on a tight budget? Go with a single-stage unit.
- Are you willing to pay more upfront for better comfort? Then go with a 2-stage AC.
In this article we’ll cover the following info:
- The difference between a single-stage and a 2-stage AC (how they work)
- Will the monthly savings from a 2-stage AC eventually pay for the higher install cost
Already know which AC stage you need to install?
Single-stage vs. 2-stage ACs: How they work
First, when we talk about “stages,” we’re referring to the technology of the AC compressor motor. The compressor is a vital part of your AC; it’s responsible for circulating refrigerant (the liquid/gas that cools your home’s air) throughout the system.
Now let’s take a look at the most basic “stage,” a single-stage AC.
Single-stage compressors run at only one speed: HIGH. So when your AC system calls for cooling, it turns on and runs at 100% capacity. Imagine your car could only go 0 MPH or 60 MPH. It’s like that.
However, compared to two-stage ACs, single-stage units run a greater risk of issues like:
- Equipment failure: From motors having to turn on and off frequently at full power.
- Wasted energy: Single-stage ACs require a lot of electricity to turn on and off at full power.
Now let’s look at two-stage ACs.
Like their name suggests, 2-stage ACs have 2 speeds: HIGH and LOW. Having 2 speeds means that the air conditioner can “ramp down” to a lower speed when there isn’t a high cooling demand.
For example, on a mild summer day (80° F), the AC would run at LOW (about 67% capacity) rather than HIGH (100%). This shift allows the AC to run longer at a slower speed, which means your AC won’t turn on and off as frequently, which means you get benefits like…
- More even cooling throughout the home: Since the AC runs longer and slower, it pushes more cold air into your home, which eliminates any hot or cold spots.
- Improved temperature accuracy: 2-stage ACs can get within +/- 2° F of the temperature you set at the thermostat, while a single-stage AC can only get within +/- 4 to 6° F.
- Longer AC lifespan: 2-stage ACs don’t start and stop as frequently as single-stage ACs, which means there’s less wear and tear on AC components so the system lasts longer.
- Lower energy bills: Because 2-stage units don’t have to run at full blast (100% capacity) and don’t turn on and off as frequently as single-stage units, they consume less energy, which lowers your monthly utility bills (although in Boise these savings are less than in other parts of the country).
Note: In addition to 2-stage ACs, you can also purchase multi/variable-speed ACs, which are more expensive, but they provide the maximum comfort and monthly energy savings. However, given Boise’s colder climate, we typically don’t recommend going with a multi/variable-speed unit for most homes.
Will the monthly savings from a 2-stage AC eventually pay for the higher install cost?
If you’ve done any research online, you may notice that some sources say that the monthly energy savings of 2-stage ACs will pay for their higher install cost.
But in Boise, that’s not usually the case.
You see, here in Boise, our cooling season is much shorter than other parts of the country, which means we don’t run our ACs as often.
Since we don’t use our ACs as often, that means you typically won’t see very high monthly energy savings from a 2-stage AC; certainly not enough to add up to the $1,000–$2,500+ it costs to install a 2-stage unit over a single-stage unit.
However, like we said in the beginning, if comfort is most important to you, then a 2-stage AC is your best option.
A couple of things to keep in mind if you opt for a 2-stage AC…
- A 2-stage AC HAS TO BE coupled with a 2-stage furnace to work, so you may need to upgrade your furnace as well.
- A 2-stage system is highly recommend if you want to zone your home. Zoning involves placing thermostats in separate parts of your home so you can control the temperature in each area, instead of cooling the entire house to the same temperature.
Want more AC advice from a Boise, ID pro?
We’ll answer any AC questions you have and we can help you choose the best AC for your Boise home.
Visit our AC install service page to learn more about what to expect when you hire us to install your AC.