For years, homeowners only had two main cooling options. They could opt for window units or install a whole-house central air conditioning system. And in most cases, the latter would be the more efficient choice. But it also came with a much higher up-front cost. Now, homeowners have another great cooling option. Mini-split air conditioning systems combine the efficiency of central AC with the flexibility of window units. But are they more efficient than central AC? We know the answer, so let’s dive in.
The Basics of SEER Ratings
Energy efficiency is a big deal these days. And for that reason, most household appliances receive energy efficiency ratings to help buyers make smart purchasing decisions. For air conditioners, the seasonal energy efficiency ratio (SEER) is the industry standard measure of efficiency. Understanding what it means is the key to grasping the efficiency differences between central AC and mini-split systems.
A SEER rating is the result of a simple mathematical equation. It’s the result of a unit’s cooling output over an average cooling season, divided by the number of watt-hours of energy it uses. The higher the SEER rating, the more efficient the unit. In the United States, it’s illegal to sell an air conditioner unless it has a SEER rating of 13 or higher. The average central AC unit sold today has a SEER rating of 16.
Mini-split units, by comparison, come with average SEER ratings of around 20. There are even mini-split systems with SEER ratings of 30 or more. It’s all but impossible to find a central AC system with a SEER rating that high. So, based on SEER ratings alone, it’s fair to say that mini-split systems are more efficient than central AC units.
Efficiency Through Flexibility
There’s another point to consider when weighing the relative efficiency of mini-split systems and central AC. It’s how each works in the real world. As their name implies, central AC systems cool the air in your entire home. That means homeowners with central AC will be paying to cool every room in their home instead of just the ones they’re using. Although some central AC systems offer multi-zone cooling options, most simply allow for separate cooling for each floor of a home.
Central AC systems also rely on ductwork to carry conditioned air from a single air handler to every room in your home. That makes the condition of your ductwork critical to the system’s efficiency. Poor insulation or improperly sealed ducts can cause energy loss that makes efficient operation impossible. And since ductwork often runs through finished walls, diagnosing and fixing such issues is no small task.
Mini-split systems, however, work much more like window units. Although they share a single outdoor compressor unit, they rely on a separate air handler in each room you wish to cool. That creates some additional efficiency benefits. First, since they’re ductless, there’s no chance of energy loss while carrying the conditioned air to where you need it. And second, you can turn each air handler on and off individually and set different temperatures for each room. They offer far greater control over energy use than central AC systems do.
Mini-splits Take the Efficiency Crown
The takeaway from all of this is that mini-split systems are typically more efficient than central AC systems. The combination of higher SEER ratings and greater real-world use flexibility means that mini-split systems offer lower operating costs in almost every circumstance. And they’re also far cheaper to install in homes with no preexisting ductwork. So, by almost any reasonable measure, mini-split systems take the air conditioning efficiency crown — and it’s not particularly close.
Getting the most out of a mini-split or a conventional central AC system means choosing the right one for your home and getting it installed by an expert. At Climate Control, we specialize in the sales, installation, and maintenance of a wide variety of heating and air conditioning solutions. We also offer duct cleaning, heat pumps, and indoor air quality solutions. We’ve got 30 years of experience and deep roots in the Portland-area community. Plus, our team of licensed and bonded NATE-certified technicians can handle jobs of every possible size and scope.
So, if you’re weighing the decision between a mini-split and a central AC, give the team at Climate Control a call, and we’ll help you pick the perfect solution for your home’s needs!