What is Stage 1 vs Stage 2 Cooling?

Q: Is a 2 stage AC worth the extra money?

If you dont mind the slightly higher up-front costs of a two-stage air conditioner, its worth it to install one. Youll not only see significant energy savings throughout your systems lifetime, but youll also have a more comfortable home.

Jared: So, you're looking to replace your cooling system. And while looking at products, you come across something that says either: single-stage, two-stage, or variable speed. What does it mean and what's the difference between each stage? In this video, we'll compare a single-stage, two-stage, and variable speed cooling to show you the benefits that each stage has to offer.

Jared: Hi, I'm Jared from Fire & Ice and regardless of your replacing just an air conditioner or a full system, you need to make sure your units match or rate in terms of single-stage, two-stage, or variable speed. In this video, we'll sit down with Arne Jacobsen, a Residential Sales Professional for Fire & Ice. And we'll cover what's the difference between a single-stage, two-stage, and variable speed cooling? What are the benefits of each stage? What's an example of a product in each stage? Who would be a right fit for each type of stage? And finally, what to do next? By the end of this video, you'll know the difference between single stage two stage and variable speed cooling and what stage will be right for you.

What’s single-stage cooling?

Jared: So, Arnie, let's just jump in and start at the beginning. What is single-stage cooling?

Arne: A single stage air conditioner is an air conditioner that operates at its full capacity all the time. So, 100% capacity all the time. When we size air conditioners and in this area, we size them for when it's 88 degrees outside. That's when they need to be at 100% capacity. Benefits of a single stage air conditioner is lower. Initial costs and also the ability to be able to call the home that it's actually designed for.

Some of the examples of a single stage air conditioner are the XR14 air conditioners and the XL16 air conditioners. The right fit for a single stage air conditioner would be a customer that has the smaller square footage home and or that they don't have temperature swings in the house.

What’s two-stage cooling?

Jared: That's great. Now let's go over what is to stage cooling?

Arne: A two stage air conditioner is an air conditioner that has multi stages of cooling. And the first stage usually operates at about 60-65% of capacity. And then the second stage operates at 100% capacity. A two-stage air conditioner is going to have the ability to be able to remove moisture much better because it does have a little longer run time. But those run times are using less energy.

The example of a product that has two stages of cooling would be an XR17 model as well as an XL18 model. The right fit for a two-stage air conditioner would be a homeowner that is having issues controlling temperatures throughout the house. If they have a two-story home, a multi-stage will be a much better fit for them.

What’s variable speed cooling?

Jared: Okay, Arne. So, what's variable speed cooling?

Arne: Variable speed cooling is an outdoor unit with a compressor that's actually varies in stages. Actually it starts at 35% and goes up to 100%. And it's all based on the outdoor temperature. The indoor temperature, the run time that is needed.

The benefits of a variable speed air conditioner is you have better temperature control in the house. To within a half to a degree or less. you're going to have better humidity control. The example of a product that has variable speed technology that would be the XV18 air conditioner and the XV20 air conditioner. Hmes that are a little larger again and have uneven temperature swings and higher humidity. Those would be a better candidate for the variable speed.

What are the next steps?

Jared: Hey, thanks a lot, Arnie. If you would like more information about single stage two stage or variable speed systems, click the link of the description below. We found this video helpful. Feel free to subscribe and hit that bell icon to be notified when we release a new video. Thank you for watching and we're looking forward to making your day better.

Differences Between One-Stage and Two-Stage Air Conditioners

The single largest difference between these two is that a two-stage air conditioner has a compressor that can operate at two distinct speeds. A one-stage compressor is either on 100%, or entirely off. The two-stage compressor has this same 100% setting, but also another that is somewhat less. While it varies depending on brand and model, this second stage is generally around 70% capacity.

You’re probably familiar with the traditional one-stage model, and equally familiar with how it will shut on and off depending on the temperature.

Say you set your thermostat to 72 degrees. The AC might let the home get to 73 before kicking on, then cool it to 72 or 71. Then the cycle repeats.

With a two-stage compressor, the system can work less hard when the temperature is close like this, thus using less energy and preventing the need to turn on and off to 100% so often.

Differences Between Two-Stage and Variable-Speed Air Conditioners

Just like the name implies, a variable-speed air conditioner can have up to 700 distinct compressor settings that correspond to varying levels of airflow. The two-stage, while superior to the single-stage compressor in terms of efficiency and options, pales in comparison to the variable-speed.

You’ve probably heard of SEER Rating and how it’s a measure of efficiency. Variable-speed air conditioners are when you start getting to 20 or more SEER rating, which is top of the line for central air systems.

Similarly to how the two-stage can operate at a lower speed when it doesn’t need to be at 100%, a variable-speed system can adjust accordingly to use only the power needed to maintain a consistent temperature in your home.

Pros and Cons of One-Stage AC

Benefits

The big “pro” here is probably an obvious one: initial price.

Single-stage air conditioners are going to be cheapest to purchase and have installed. If you’re on a budget, this is probably your best bet. The good news is, a one-stage AC is still going to cool your home adequately, provided it’s sized properly and installed correctly. So you don’t have to worry on that front.

Drawbacks

The cons are mostly related to efficiency and long-term costs. Your energy bills will be higher since it’s using 100% of its power, 100% of the time that it’s on. While modern systems tend to run very quietly, the start and stop of the air conditioner can also be an annoyance to some.

Example of a Single-Stage Air Conditioner

The XR13 home air conditioner’s SEER rating of up to 14.5 gives you the right mix of cooling and energy efficiency, which may help lower your home cooling costs. The XR13 air conditioner system comes with the reliability you expect from Trane and the comfort your home deserves. Built with you in mind, this home air conditioning system’s design helps deliver cool air to every room in your house, allowing you to relax comfortably.

RELATED: Trane XR13 Product Page

Pros and Cons of Two-Stage AC

Based on the pros and cons of a single-stage AC, you can probably see where this is going. Two-stage air conditioners are going to provide more efficiency compared to a single-stage air conditioner. They’re a nice middle ground between low-end and high-end efficiency and initial cost and will save you on energy costs compared to a single-stage.

Think of it like gas mileage. It’s more efficient to drive at slower speeds than higher speeds, and slamming the pedal can produce long-term wear and tear on your car. The benefits of having a second, slower stage is somewhat similar in terms of efficiency and system usage.

Depending on the model, brand, and other factors like the size of your home, the initial price tag can be closer to single-stage or variable-speed, so you’ll want to consult with an HVAC professional before determining if this is right for your budget.

Example of a Two-Stage Air Conditioner

The Carrier 24ACB7 Air Conditioner offers that perfect balance between budget limits you may have today and your desire for long-term energy savings. At up to 17 SEER rating, the two-stage compressor in this unit will help keep you cool at a reduced cost.

RELATED: Carrier 24ACB7 Product Page

Pros and Cons of Variable-Speed AC

Benefits

Variable-speed air conditioners are the Cadillacs of central air cooling. They’re going to run the most efficiently, and will generally be the quietest as well, since they’re often operating as low as 40% of their maximum power capacity.

You’re also going to save the most on energy costs, and have the greatest degree of control over the temperature in your home. You’ll experience fewer spikes in temperature, like those that happen when single-stage systems or even two-stage systems turn on and off.

In short, your home will be more consistently comfortable.

Drawbacks

The primary downside is the initial cost. The systems don’t come cheap, even if they largely make up that cost in the long run.

The other downside is also related to cost, but regarding repairs. If a part breaks, it can be costly regardless of the system. But the advanced technology inside a variable-speed air conditioner can often incur increased replacement costs and labor costs.

Even if a system is under warranty, most don’t cover labor costs, so you can still be on the hook for more than expected depending on the repair. Be prepared to discuss this with your HVAC partner before choosing this type of system.

Example of a Variable-Speed Air Conditioner

The Trane TruComfort™ system gives you precise comfort by running at the exact speed needed to keep your home comfortable. This allows the compressor, outdoor fan, and indoor fan to vary operating speed as the temperature outside changes, slowing down or speeding up gradually in as little as 1/10 of 1% increments to keep comfort within 1/2° of the thermostat setting. The XV20i TruComfort™ Variable Speed unit is one of the industry’s most efficient air conditioners. On the hottest days, it cools with precision, keeping you comfortable all day. The unit has up to 22 SEER with 750 stages of comfort for ultimate climate control and maximum efficiency.

RELATED: Trane XV20i Product Page

Why Your Furnace Type Matters

You may have heard of the term “equipment matching.” If not, all it means is that the different pieces of equipment in your HVAC system need to be compatible with one another. This is usually in reference to your furnace and air conditioner.

The blower motor in your furnace regulates airflow in the entire system, including the air that’s conditioned by the AC unit. So to run a variable-speed air conditioner, for example, you need to have a compatible blower motor that’s capable of handling the varying stages of the cycle.

This can mean that it’s sometimes impossible to upgrade from a single-stage to a two-stage, or a two-stage to a variable-speed, without also upgrading your furnace/air handler.

So what do you do in these situations where you’d need to upgrade your furnace to install a variable-speed air conditioner? Well, how old is your furnace? It’s often very cost-effective to replace both the air conditioner and furnace at the same time. But if your furnace is still fairly new, it’s probably time to explore options that don’t include a variable-speed AC.

Humidity and Air Quality Differences

Humidity affects the temperature of the room, or more specifically how it feels to us. 70 degrees in Arizona is not the same as 70 degrees in Florida.

When an air conditioner runs, it’s removing humidity from the air as well. This makes the system’s operation more efficient.

So it should come as no surprise that because a two-stage AC runs for longer than a single-stage (albeit at a lower power level), it’s removing more humidity from your home. Similarly, a variable-speed system will remove even more humidity.

It’s often a great idea to pair a whole-home dehumidifier with an air conditioner to increase its efficiency. This is true of any type of system, but can be another consideration as you weigh your options between system types. Depending on the average relative humidity of your home, and the type of air conditioning system you end up with, a discussion about dehumidifiers is a good one to have with your HVAC contractor.

Similarly, a system that runs for longer, which a variable-speed system will do, is circulating air in your home more frequently. This, in turn, will remove more particulates from the air. This is good news for your overall air quality, but can occasionally have implications for things like frequency of filter cleaning. Make sure you’re aware of these and any other considerations that your HVAC provider considers relevant.

How Much Can I Save With Higher SEER Rating?

Depending on the system you have currently, the answer could be quite a bit. Assuming the system is installed to code and is running efficiently, you could be looking at 65% savings annually!

Granted, that’s a jump from an 8 SEER system to a 22 SEER, which is pretty rare, but it’s a good example to show you what’s possible when you go from older equipment to the best modern equipment.

It’s also important to note that some jumps aren’t as pronounced. The expected cost difference between 15 and 16 SEER, for example, is only 3%. At that point, the discussion becomes as much about comfort and budget as it does about annual cost savings.

Choosing the Best Air Conditioner

There isn’t a “best” option here, but there are better options for individual homes and homeowners.

In learning about the different types, we hope you have a better idea of which one might be for you. Here are a couple more considerations that sometimes help homeowners make the decision.

How long do you expect to stay in the home? If it’s less than 5 years, you won’t see a lot of the long-term cost savings from a variable-speed system. But if you’re planning on raising a family in this house, for example, a more efficient system often makes more sense.
In this case, size can make a difference. Modern systems are more efficient than older systems, but they’re also larger as a result. And variable-speed units are the largest of the bunch. Make sure the area where you’re planning on housing your outdoor air conditioning unit is indeed big enough for the dimensions of the equipment. This can apply to height as well, if you don’t want a unit peeking over a window sill.

There will be even more considerations for many, but they’ll be specific to the homeowner. If you’re in Columbus, OH or the surrounding area and are ready to figure out which is the best fit for you, click below to schedule your free in-home estimate.

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Which is better 1 stage or 2 stage air conditioner?

Two-stage air conditioners are going to provide more efficiency compared to a single-stage air conditioner. They're a nice middle ground between low-end and high-end efficiency and initial cost and will save you on energy costs compared to a single-stage. Think of it like gas mileage.

Is a 2 stage AC worth the extra money?

If you don't mind the slightly higher up-front costs of a two-stage air conditioner, it's worth it to install one. You'll not only see significant energy savings throughout your system's lifetime, but you'll also have a more comfortable home.

What is a 2 stage cooling system?

Two-stage cooling means the air conditioner or heat pump has a compressor with two levels of operation: high for hot summer days and low for milder days. Since the low setting is adequate to meet household-cooling demands 80% of the time, a two-stage unit runs for longer periods and produces more even temperatures.

What is stage one cooling?

A single stage heating or cooling system means your furnace or air conditioner has only one level of heat or cold output. Single stage thermostats are used to control single stage HVAC systems—thus, if you have a single stage heating and cooling system, your home needs a single stage thermostat.