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February 16th, 2023
Let’s talk about automobiles for a moment. Take any car. If it is safe, fuel-efficient, and easy to operate, it may be considered high-quality. If this same car continues to meet these criteria for several years, performs well, and remains safe even when driven in bad weather, it may be considered reliable.
Notice we didn’t talk about what features it has. We didn’t mention the price. The make and the model don’t matter. We don’t care what color it is, or how great it looks in car commercials.
A reliable car makes for a happy driver. And isn’t that enough?
Sure, you may want to spring for a BMW when you hit the lottery. And maybe on your next purchase, you’ll want the model to have better gas mileage.
But there’s something to be said about knowing your current car is sturdy and dependable.
Now, let’s talk about air conditioners.
If you’re in the market for a new one and aren’t sure where to turn for answers to your many questions, let this article be your guide. We’re going to go into the category of AC known as single-stage (more on that term in a minute). It’s tried-and-true technology that could be the perfect solution to your cooling needs.
It might even be called “reliable.”
What Is Single-Stage Air Conditioning?
Single-stage means that an air conditioner only has two settings: ON and OFF. It’s either running at 100% of its capacity, or it’s resting.
Single-stage air conditioners have been around for decades. Only in recent years have two-stage and multi-stage (or variable-speed) air conditioners become more popular.
A two-stage air conditioner unit will have one additional setting, usually 60% or 70% output. Variable-speed units can have hundreds of settings, generally ranging from 40-100% cooling output.
The newer technology doesn’t mean single-stage is obsolete. In fact, single-stage units are still reliable workhorses for many homes and can provide excellent home cooling and complete comfort. And comfort is what HVAC should be all about.
Compared to an older, inefficient unit that you may have in your home, a single-stage AC unit can also save you a lot of money. This depends on the specifics of your current system, and gets us into discussions about SEER Rating and average cost savings.
Read more: Single Stage, Two Stage, Variable Speed Air Conditioners
How Does a SEER Rating Measure Efficiency?
SEER Rating stands for Seasonal Energy Efficiency Ratio. It’s a calculation that looks at the average energy use over a typical cooling season. A higher SEER Rating means greater efficiency.
Typical modern air conditioners range from about 14 SEER to 22 SEER, and single-stage ACs tend to be on the lower end of efficiency. For example, a Carrier 24ABC6 has a SEER of 16.
This doesn’t mean it’s inefficient. Large gains in efficiency, as well as breaks on your utility bill, can come when you transition from lower SEER Ratings (often 8-10 for older models) to new models. For a typical new installation, homeowners often save 40-50% off cooling costs.
What Are Two-Stage and Modulating ACs?
A two-stage air conditioner does what its name implies: it has two operating modes. The first setting is 100%, which will be in use during the hottest of days. But when you don’t need as much cooling, it can ramp down to 60-70%.
Running it at this level accomplishes several things. It has a longer run time than the single stage, which allows the conditioned air more time to mix with the stale air. That eliminates hot and cool spots in the home better. It’s perfect for warm days when you need only a little bit of cool.
And even though it runs longer, it actually is a money-saver. That lower speed allows the AC to do its job without running at 100%. It also shuts off and on less. Both characteristics will make a dent in your energy bill.
And a modulating unit (also called a variable speed) is the ultimate in comfort. It can ramp up or down as the outside temperature changes, leaving the indoors at a constant temperature all of the time. You can set the thermostat and forget it; the AC will adjust as needed.
It mixes the air better, costs the least to operate, treats humidity the best, and - naturally - costs the most.
Do You Have to Sacrifice Quality in a Single-Stage AC?
Let’s consider a couple of models.
The Carrier Comfort 13 Central air conditioner, like all of Carrier’s models, has design and durability features. For example, the Comfort 13’s cabinet is protected using Weather Armor Ultra, including a galvanized steel cabinet, louvered coil guard, and powder-coated paint to protect against damage and the elements.
And just because you’re buying one of the more affordable options doesn’t mean you have to sacrifice efficiency. You’re not stuck with a single SEER rating. You can do a 14 SEER or a 16 SEER.
If you want to step up a bit, the Carrier Performance Series 24ACC6 has a SEER of up to 17.
These are so efficient that they qualify for Energy Star rebates.
(Energy Star is a program run by the U.S. Environmental Protection Agency and the U.S. Department of Energy that promotes energy efficiency. Energy Star-qualified central air conditioners must have a SEER of at least 14.5.)
Who Is a Single-Stage AC a Good Fit For?
- People who have been very happy with a single-stage unit for 20 years tell us, “I don’t want to change.” Then a single-stage air conditioner is a great solution for you and your home.
- If you have a ranch-style home and you have adequate ductwork, generally a single-stage AC will keep it pretty comfortable.
- For cost-conscious buyers, it is the least expensive option.
- If you’re living in a rental home, you certainly don’t want a high-end unit. You want something that can cool and run for 15-20 years.
- I had a customer who keeps her AC set at 78-80 degrees. She doesn’t need the additional cooling power of a multi-stage unit. Why would you pay for anything more? She’s still going to see significant savings with a new air conditioner that has a higher SEER even though she won’t use it as much as our typical homeowner.
Who Is a Single-Stage Not a Good Fit For?
- We always talk about customers’ unique need for comfort. The house style can play a big factor. If you own a two-story or split-level home and have issues with the upstairs being considerably warmer and more humid than the downstairs, the single-stage AC won’t do as good a job.
- The question I ask people is if you’re going to be spending five years or less in your home. If you are planning on moving out in a few years, comfort concerns could sway you to pay a little bit more. But to recoup the energy savings that would offset the higher price tag of a variable-speed AC, you’re looking at 7-12 years at least.
- It’s not going to be able to dehumidify as well. It’s not going to run as long so it won’t move as much air. ACs remove excess humidity from the home only while they are running.
- One drawback to the single stage model is that it cools quickly. Once the set temperature is reached it shuts off. That doesn’t give the air as much time to mix as a two-stage or modulating.
- Single-stage ACs are going to be louder than their more expensive brothers. For instance, The Carrier Comfort 13 (24ABB3) air conditioner’s sound level is 73 decibels (a normal conversation is about 60 decibels). If this unit is located next to a patio, if you plan on having parties out there, you may want to consider upgrading or moving it somewhere else. Compare that to the Carrier 24VNA9 air conditioner, a five-stage air conditioner that can run as low as 56 decibels. That’s a huge difference, but you will pay a higher price for the quiet.
Read more: Cost of an Air Conditioner Replacement, a Complete Breakdown
How to Add Comfort to a Single-Stage AC
If you’re thinking about a single stage air conditioner but would like to add a piece of HVAC equipment to it to enhance its cooling and dehumidification abilities, there are options.
- You could replace your furnace at the same time and spring for one that has a variable-speed fan. Why? Because a furnace’s fan blows the conditioned air through the house. And furnace fans come in three varieties: single-speed, two-speed, and variable-speed.
A variable-speed fan operates much like a modulating AC. It can deliver conditioned air at a multitude of speeds. The air conditioner will still operate at its maximum cool, but the fan can deliver the air slowly if that’s all the house needs, or at full blast on 95-degree days. And as a bonus, your furnace will deliver heat in the winter using the same technology.
- Leave the furnace’s blower motor on even if you’re not running the air conditioner. At least you’ll be moving air even though it’s not cooling. On your thermostat, set it to “on” instead of “auto.” It won’t lower the temperature, but keeping the air moving will even out the indoor air temperature.
- You can add a dehumidifier to the equation. Read on.
Adding a Dehumidifier to an Air Conditioner
High humidity makes you feel warm and clammy. Reducing humidity can make you feel two or three degrees cooler when the thermostat is set to exactly the same temperature.
If you’re happy with the single stage but still have humidity concerns, there’s an answer. Large-capacity dehumidifiers can be stand-alone or ducted and can reduce humidity. The stand-alone model would dry out a large area - say, your basement. That would prevent the humidity from seeping up into the main and second floors.
We call that the “sniper effect.” It gets rid of humidity at the main source.
If you put the dehumidifier in the main duct, it takes on the whole house’s moisture. That’s called the “war of attrition.”
Both methods are effective. For instance, the Aprilaire E100 can remove 100 pounds (12 gallons) of water per day. It has a 5-year warranty and doesn’t have a tray you need to empty if it’s ducted.
To be clear, lowering the humidity doesn’t lower the indoor temperature. But it does make your skin feel cooler. On a sweltering day, that can make the difference between sweating and not.
Video: Dehumidifiers and Indoor Air Quality https://vimeo.com/438922763
Buying a Single-Stage AC in Columbus, Ohio
A thorough heating and cooling expert should bring an open mind when meeting with you. They need to consider the square footage of your home, how many occupants (the greater the number, the larger the cooling needs), your budget, the size and specifications of your current AC, and the style of the house.
They also need to consider your existing comfort level versus what comfort level you desire.
There are no black-and-white answers in the world of HVAC. A ranch home with two occupants is vastly different than a split level with four. Some folks like to keep their thermometer set at 68 degrees Fahrenheit in the summer; others set it at 78.
When you meet with an HVAC contractor, make certain they understand your unique home and your unique concerns. If they don’t, they’re not the right fit.
We would love to have a conversation with you to discuss single-stage air conditioners or any other HVAC aspects. Fill in your zip code in the graphic below to see if you’re in our service area. We hope to hear from you soon.
