Comparing Ductless Mini-Splits to Window Air Conditioners

HVAC professionals call window air conditioners “window rattlers.” It’s not complimentary, though we see them in use all of the time.

They solve a big problem with a minimum of fuss. You can buy one for a few hundred bucks, or can splurge and buy one with a greater capacity to cool for a thousand bucks or so. Installation can be messy, but once it’s in place, it can cool off a problem area, such as a master bedroom suite.

If they give you a good night’s sleep, they’re worth every penny.

But they have limits, and there might be a better option.

If you have a window air conditioner (or several) and are thinking about a different solution for a room that’s too warm, a ductless mini-split might be an attractive alternative.

If you’re pondering such a switch, this article is for you. You can continue to put up with your window rattler for as long as you like, but the advantages of the alternative are many. Let’s compare the two options.

Why Might You Need Additional Cooling?

If you have hot spots in your house, it might be a sign that your air conditioner or heat pump isn’t performing at 100%. It may that it’s undersized, so it can’t keep up with the sultry weather.

It may be oversized due to a pushy salesperson’s desire to sell you a unit that is a bit more costly. What’s wrong with an oversized unit? It does what we call “short cycling.” It turns on, satisfies the thermostat, then shuts off quickly. That cold air isn’t given time to mix with the hot spots in your home.

But if you’re not ready to talk about a whole new HVAC system, there are alternatives.

Regardless of the cause, you’re looking to cool off. Maybe it’s the computer room, or an under-insulated room above the garage. One solution is a window air conditioner. Another is ductless mini-splits.

Advantages of a Window (or Room) Air Conditioner

• They are cheaper than the alternative.  A window AC can be as cheap as a few hundred bucks.
• They are portable. Want to move it from one area to another? No problem. As long as the window is the same size, you can make the switch. And if we’re talking about a room air conditioner, the transition is even easier.
• They are simple to operate. Push the button, twist the dial, and it’s off and cooling.

Disadvantages of a Window (or Room) Air Conditioner

• They are not pretty, especially from the outside. Aesthetically, they have nothing going for them.
• They can be a pain to install. A narrow window ledge means that you might have to support the unit if it doesn’t fit squarely. You might need brackets or foam insulation to seal the cracks. If you want to move them, you’ll have to refit the unit to a new space. And they are not light.
• They are energy hogs. On average, a window AC unit can use between 500 to 1,500 watts of electricity to run. A midsize window air conditioner that uses 900 watts of electricity will consume approximately 200 kilowatt-hours of electricity each month if operated 8 hours per day.
• When it’s running, it dehumidifies that air. But when it stops, so does the dehumidification.
• Even the trimmest of models is going to block some of the views.
• It only cools. In the winter, it’s worthless.
• And they are LOUD.

Advantages of Ductless Mini-Splits

The huge advantage a ductless mini-split has is that it can heat and cool, just like a heat pump. It is a long-term solution that can keep a room comfortable all year long. It can turn that one room in your house that runs hot and cold into the most comfortable spot.

Just as you can buy multiple air conditioners, you can have multiple heads on ductless mini-splits.

Ductless mini-splits are much quieter. With the system split between an indoor and outdoor unit, the only noise in the room is the fan needed to move air. There is none of the loud compressor hum that is typical of a window unit.

In addition, most quality mini-split systems, much like the best whole-house systems, use variable-speed motors in their compressors. It’s rarely running at 100%; once it satisfies the thermometer, it throttles down to a low speed to keep the temperature steady.

On mild days, a ductless mini-split will run at a slower speed than on a hot day and save you energy. A window unit will turn on and off and on and off. This cycling of the window unit consumes a lot of energy. Think of it like trying to push a car from a dead stop to 5 mph versus pushing it as it’s already rolling forward. Which one requires more energy? The variable speed motors in a ductless mini-split are never at a dead stop.

It may sound counter-intuitive, but a machine that runs a lot at a slow speed consumes far less energy than one that comes on at 100%, then shuts off, and repeats its cycle throughout the day.

The ductless mini-split will do a much better job of dehumidifying the air. Since the ductless mini-splits variable-speed can ramp down to near zero once the target temperature is reached, it can keep dehumidifying while it maintains the ideal temperature. And guess what? In the summer a lower humidity means the air will feeler cooler. That will allow you to set the mini-split at a higher temperature, which further reduces energy costs.

A mini-split can disperse air in a sweeping motion from side to side, up and down, or even directed towards a wall if you want some circulation without a direct blast of air. Some models even have a sensor that can automatically tell if you want the air directed toward you or away from you.

A mini-split doesn’t occupy a room’s electrical outlet or affect the function of your windows. A window AC completely blocks a good chunk of the window, obviously. And even a portable AC hogs its share of the window space by requiring the window to stay shut tight against the hose that the AC uses to dump heat outside.

You can create zones with mini-splits. For instance, if you have a system that has three heads, you can have different temperatures in three different rooms at the same time.

Upscale window air conditioners can be operated by a remote; nearly all mini-split systems do. That means you can change the temperature from your chair, and program when you’d like the AC to turn on or off.

Disadvantages of Ductless Mini-Splits

Mini-splits are nice in that they are all-electric (and require no additional fuel or gas service, as with some traditional HVAC systems), but their electrical requirements are considerable. A 5-zone unit may require a dedicated breaker, requiring an electrical contractor for the work, which adds cost.

You also have to commit to a location with ductless. There’s no relocating them. Ideally, the pipes go through the wall directly behind the unit, where they’re hidden. On the other side of the wall, the line set has to run to the outside unit. That line set is covered by something called a line hide, which helps with the aesthetics. Some models can even be painted, which will help them blend into the exterior.

Ductless mini-split indoor units do take up a chunk of wall space. Some homeowners see that big rectangle and have second thoughts. Some manufacturers offer a variety of colors, at least. Another option is to get units that recess into the floor or ceiling. But these installations will likely be more expensive.

Ductless Mini-Splits in Columbus, Ohio

Columbus and Central Ohio homeowners ask us frequently about ductless mini-splits, and for good reason. They are relatively new technology-wise, but they offer many benefits. And the things they do well, they do extremely well. They alleviate a host of comfort concerns.

Unlike traditional heat pumps, ductless mini-splits can perform well in extreme temperatures. According to Mitsubishi Electric, their best systems can operate at 100 percent capacity all the way down to an exterior temperature of about 23 degrees F and will even operate at 75 percent capacity at negative 13 degrees F.

Who should be considering one? If you have any “nuisance” areas in your home, this is the first clue that a mini-split might be right for you. We discussed some of them earlier: Garages, patios, sunrooms, home additions, guest rooms, attics, or others areas such as this. If these rooms run hot or cold too often, or don’t have ductwork running to them, they’re ideal candidates for a ductless system.

The cost savings can be immense over 12-15 years due to the equipment’s efficiency.

If you’re considering a ductless system, there’s no bad time to speak to a licensed HVAC contractor to discuss your specific options, get a free estimate, and make the decision that’s right for your home.

If you’re in Columbus, OH, or surrounding areas, Fire & Ice can help with that decision. We’d love to educate you on all your options and help you determine if a mini-split is right for you.

Read more:

Ductless Mini-Splits 101: What They Do & How You Benefit

Ductless Mini-Splits vs. Central Air: Pros and Cons

Ductless Mini-Splits: A Comprehensive Cost Breakdown