Is an air conditioner just an air conditioner? No, as oddly counterintuitive as that sounds.
So what makes one air conditioner better than another? Is it the brand? The year it was made? Who installed it?
To some of those, the answer can be “yes” but each of those questions ignores a really big differentiating factor for AC units: staging.
The number of stages your air conditioner can operate at is among the biggest factors that affect comfort and cost efficiency.
What are stages, and what makes them beneficial to your home comfort and energy efficiency? That’s what this article is about.
At CABS Heating and Air Conditioning, we’re experts in cooling your home through a variety of equipment upgrades and services. Your air conditioner is the biggest single contributing factor to cooling, so it’s worth knowing why you might want to consider different types of air con units.
How Air Conditioners Work
Cold air goes brrrr! Right?
Ok, jokes aside, we’re always surprised when we realize how many people don’t fully understand the cooling process. And it’s because air conditioners don’t actually produce cold air!
Rather, what they’re doing is absorbing heat from the air and expelling it outside your home.
Further, the way your entire home is cooled is via air circulation. This is where your ventilation system and blower fan come into play. With the heat removed, the air is recirculated. But warm air still exists in your home until it’s suctioned into the return air ducts and circulated through your air conditioning system to have the heat absorbed.
Therefore, thorough airflow that circulates all the air in your home is critical to actually keeping it cool.
We aren’t talking about this without reason. This relates to why certain types of equipment are more energy efficient than others.
Single-Stage Air Conditioners
If your current air conditioner is more than 10 years old, or you live in a rental home, this is almost certainly the type of air conditioner you have.
Single-stage air conditioners are the most common type of air conditioner. The technology that powers them has been in use for decades.
This makes them reliable for a lot of cooling purposes. But it also means that single-stage air conditioners haven’t kept up with modern advances in cooling technology.
So how do single-stage systems work? As the name implies, single-stage air conditioners operate at a single setting. The unit is either on or off, at full capacity or not in operation.
This might seem normal, and it is, but imagine a blender with different speed settings on it. Certain settings are useful for different situations.
Similarly, do you bake everything in your oven at the same temperature? Of course not. It’s useful to be able to set the oven to different temperatures. Air conditioners are kind of the same way.
Two-Stage Air Conditioners
Keep that blender/oven analogy above in mind as we discuss two-stage air conditioners. It’s basically the blender with a 2nd setting, to be able to make different types of concoctions.
In this case, two-stage refers to one additional power setting besides 100% that the system can operate at. Usually this is 60% or 70% but it varies depending on the brand and model.
What does this matter for efficiency and comfort? Well, remember above where we talked about how thorough cooling comes from properly circulating all of the air in your home. This is where that lower setting excels.
Because at 100%, your AC is going to cool the air near your thermostat fairly quickly. Your thermostat is usually on the main level in a central room and isn’t near a window.
But if that spot is the correct temperature, what about the corner of the room? What about your second floor? What about your master bedroom that’s on the opposite corner of the home from the air conditioner and has the most windows in it letting sunlight in?
If the air at your thermostat is 70 degrees, these areas are much hotter!
The solution is to cool the home more gradually to allow for better air circulation. Two-stage systems give the air more time to change through the air conditioning unit, and circulate more of the air in those hard-to-cool corners of the home.
It uses less energy as well, which is an additional bonus.
Variable Speed Air Conditioners
The same principles apply to variable speed that we just talked about for two-stage ACs. It’s just a lot more powerful.
Variable-speed air conditioners can have hundreds of settings. It’s much more like the oven analogy we used earlier. Maybe the ideal power level to maintain a particular level of coolness is 40%. Maybe it’s 100%. Or maybe it’s any percentage (or even fractions of a percentage!) between those.
This allows for the best air circulation, the most even cooling in the home, and uses the least amount of energy. Variable speed systems can still cool your home as quickly as the single-stage unit, but have a lot more functionality to keep you cool in any room. The best variable speed units can often keep your entire home within a half a degree of temperature. This is a level of control single-stage ACs simply can’t recreate.
HVAC Equipment Matching
So ok, you want to upgrade your air conditioner. But have you considered the rest of your HVAC system?
This isn’t a sales pitch, but it is a reminder that there are parts of your HVAC system that work with both the cooling and heating portions of your system. This matters for the overall efficiency of your system.
For example, to install a variable speed air conditioner, you’ll be upgrading your blower fan, the motor for which is what controls the power level for your AC.
If you have a furnace that’s single-stage, the same blower fan can handle both cooling and heating. But you’re losing out on functionality in your blower fan during the heating season, since it can do more than the furnace unit allows for.
Some variable-speed systems are also sophisticated enough that they require a compatible thermostat to operate fully. The best systems adapt and learn from your home to operate more efficiently, so the thermostat needs to be communicating with the cooling unit at all times.
This will all be baked into an air conditioner installation cost, but it’s worth knowing that the price can increase due to these factors. What if the smarter thermostat requires new wiring to be run from your air conditioner to the thermostat? A licensed electrician may need to do additional work outside of the AC installation itself.
Cost and Energy Savings on AC Upgrades
Will a variable speed air conditioner pay for itself over time? It can, but the answer depends on longevity of the system, usage rate, energy costs where you live, and more.
Your HVAC, on average, accounts for about 40% of your energy costs overall. And a two-stage AC or variable speed AC can improve your efficiency and lower your bills for that portion of your overall cost. However, the initial cost of these units means that they may not “pay for themselves” over a single-stage unit for many years.
Conversely, a lot of times there are tax rebates or other discounts available in states that incentivize eco-friendly equipment. You can often lower your initial bill by thousands of dollars by upgrading to a more sophisticated AC unit.
So if you add all of that together, the total cost savings over the lifetime of your air conditioner (typically 10-15 years) can be considerable! You’ll still be paying more upfront, but you’ll slowly gain it back over time and will also enjoy greater cooling comfort.
Which AC Type is Right For You?
One of the things we tell customers, though, is that the choice of equipment is about more than just cost. Ask yourself these questions:
- How uncomfortable am I currently in my home with traditional, single-stage equipment?
- Are there any rooms that never seem to get cool in the summer?
- How much importance do I put on having eco-friendly green technology?
- How long do I plan on staying in my current home?
None of these have to do with energy savings, but they’re often more important to many homeowners.
The right solution for you is the one that you’re confident about, though, which will only come with a no-pressure quote from a trusted HVAC specialist. Most quotes should include each of the types mentioned above, single-stage, two-stage and variable speed air conditioners. It’s possible you’ll eliminate one of these as a possibility, but any HVAC company worth its salt will provide you with options to consider that meet a variety of cooling and budgetary goals.
