4 Reasons to Consider Ductless Air Conditioning

Ductless air conditioning – and ductless heating, too – suffers from a few misconceptions. Some consumers think ductless is the answer to all their A/C problems. Other consumers think ductless is subpar to central A/C systems. But neither is true. Instead, ductless air conditioning is best judged according to the scenario where you’re thinking of using it. So today, we’re giving you four reasons to consider ductless air conditioning.

This post lists four cases when ductless A/C makes sense for you and your home. If you’re thinking of upgrading your air conditioning, the information here should help you decide between ductless and central air conditioning.

Here’s what we’ll cover:

Let’s get started!

What is Ductless Air Conditioning?

Before we dive into where ductless works best, let’s define what it is.

Ductless air conditioning is a system of cooling a room or area without using any ductwork or venting to direct or circulate the air.

Today’s ductless A/C has evolved far beyond the clunky window units of old. A modern ductless air conditioning system consists of well-designed equipment with advanced technology built-in. It looks sleek, cools efficiently, and runs quietly.

Ductless A/C has indoor and outdoor components. In fact, ductless A/C is often called a “mini-split” because of these indoor and outdoor components. It is a two-part system just like a central split HVAC system, but on a smaller scale:

  • Located inside is the air handler. It is typically mounted to an exterior wall and contains evaporator coils and a blower. The air handler delivers cool air into the area where it’s mounted and disperses it throughout the room.
  • Located outside is a unit that houses a compressor, condenser coil, and fan. Ductless systems used for heating also have a heat pump outside.
  • Connecting the indoor and outdoor components are refrigerant tubing and electrical wiring.

Compared to central A/C, ductless A/C can cost about the same, run at about the same efficiency level, and last about as long.

So why consider ductless A/C at all? Because it excels in certain situations. We’ve identified four. Let’s get into them!

Reason #1: When a Specific Room Needs Supplemental Cooling

“Supplemental” is the ideal use for ductless A/C. If you already have central air in your home, but you need to bring additional cooling to another room, ductless is an excellent choice.

The kinds of rooms that benefit from ductless air conditioning are those that you’re converting into a living space or those that your central air doesn’t cool consistently (or at all), like the following:

  • Sunrooms
  • Attics
  • Basements
  • Garages, whether attached or freestanding
  • Bonus rooms above a garage

Ductless A/C works well in these kinds of rooms for two reasons:

Precise Temperature Regulation

Sunrooms, attics, basements, garages, and bonus rooms tend to run warmer or cooler than the rest of your home. This is due to a variety of factors, including their location, ceiling height, lack of insulation, limited ventilation, an abundance of windows, or some other structural challenge.

Ductless A/C combats these issues with inverter technology, which continually monitors and adjusts the temperature in a specific area. You set the temperature for the indoor air handler, and your ductless A/C cools the room precisely and consistently according to that temperature.

Basically, ductless A/C offers targeted zone control in a way that central A/C does not.

Ease of Installation 

Getting central A/C to sunrooms, attics, basements, garages, and bonus rooms typically requires:

  • Extending ductwork into difficult-to-reach places. This means opening up walls and ceilings at a much larger scale than for ductless A/C, which needs only small-diameter tubing and wires.
  • Upsizing your current central A/C system. Your current A/C may not have the capacity to properly cool additional square footage.

A qualified HVAC pro can certainly install or upgrade your ductwork, plus replace your central A/C with a system that’s properly sized for your whole living space. But given how well ductless A/C works for supplemental cooling, the additional labor costs of installing ductwork may not be worth it.

Reason #2: When You’re Building an Addition

If you are adding living space to your home, ductless A/C offers the following advantages:

Size is Not an Issue 

Whatever the size of your addition, ductless A/C can probably handle it. Ductless A/C systems are available in sizes ranging from 9,000 BTUs to 36,000+ BTUs. This means that a single-zone ductless A/C (that is, one air handler and one compressor) when properly sized, can cool a space that’s 400 square feet or less to one that’s 1,500 square feet or more.

If you are building a multi-room or multi-level addition, you may need to install multi-zone ductless A/C to cool it well. Multi-zone ductless A/C consists of two or more indoor air handlers in different rooms connected to a single outdoor compressor.

In a multi-zone ductless system, the size and placement of the air handlers (also called  “heads”) are critical. A too-small system will have to work too hard, and a too-large system will short cycle (that is, turn on and off too quickly). Either way, you’ll compromise your comfort and drive up your electricity bills.

We usually say that if you’d need four or more air handlers, you are likely better off with central A/C, from both a comfort and efficiency standpoint. But every home, homeowner, and addition is different. You should speak with an HVAC professional before you decide on a cooling solution for your addition – and definitely before you finalize your addition’s design with your architect or contractor.

Shape is Not an Issue

The air dispersion technology in modern ductless A/C systems thoroughly cools even those rooms that aren’t open squares or rectangles. So if the space you need to cool is L-shaped, or features dormers or bump-outs, ductless A/C will work well through all the angles, nooks, and crannies.

Extra Space is Not Necessary 

Central A/C requires space for ductwork and indoor mechanicals. Ductless A/C does not. So in the design and construction of an addition that uses ductless A/C, you do not need to carve out this extra space.

This gives you more flexibility in your design and more livable space in your addition.

Individual Temperature Control is Easy

As we mentioned earlier, ductless air conditioning enables very tailored cooling in the room where the air handler is installed. This is especially attractive if you expect any “thermostat wars” among the various people in under your roof.

Potential family disagreements aside, there are many scenarios where the temperature in your addition will legitimately need to differ from the temperature in the rest of your home. This includes additions for:

  • Aging parents
  • Guest bedrooms
  • Nurseries
  • Home gyms
  • Game rooms or other rooms for large gatherings

Basically, the precise climate control of ductless A/C can save you a lot of hassle and expense over the long run. And since home additions are already a hassle and an expense, ductless A/C can be one less thing for you to worry about.

Reason #3: When Your Home Does Not Have Ductwork 

It’s right there in the name: “ductless” air conditioning works without ducts. So if your home uses a boiler system or electric baseboard system for heat, and you’d like to install air conditioning, ductless A/C is ideal.

In homes that do not have forced-air heating, ductless A/C is a fantastic option for the following reasons:

  • Ductless A/C delivers the same cooling power and efficiency that central A/C does without requiring you to ditch or revamp your heating system.
  • What you can ditch are the fans, window units, and portable units you may have been using to cool off and the limited relief they provide in extreme heat.
  • You can get superior air conditioning without the added expense and major overhaul of installing ducts and vents throughout your home.

Reason #4: When Design Aesthetics Aren’t a Factor

Earlier, we mentioned that modern ductless A/C is well designed and looks sleek. This is true. Ductless air handlers are typically rectangular units with a polished exterior. They’re fairly subtle and quiet, so they don’t dominate a room. But they’re more intrusive than a vent, which is the delivery mechanism for cool air from central A/C systems.

This means that ductless A/C can present a few design considerations, both indoors and out:

Indoor Design Considerations

Ductless air handlers, on average, are about three feet wide, one foot tall, and less than a foot deep. They are not very obtrusive, but they do interrupt the flow of any design scheme because they are typically mounted to the wall or floor.

If seamless design is important to you, ductless A/C might not be your first choice. But air handlers can be disguised or even hidden in the following ways:

  • They can be painted to match the wall color.
  • They can be covered with a decorative grate.
  • Framed artwork can be mounted to them. Granted, the artwork extends out farther than it would if it were mounted directly to your wall. But the effect is still visually pleasing.
  • Air handlers can be installed via a cassette in a drop ceiling. Ceiling units are practically invisible, unlike wall or floor units. But ceiling units tend to have more issues with condensation drainage. We recommend ceiling units more often for commercial, rather than residential, applications.

Outdoor Design Considerations

A ductless air handler (whether it’s mounted to a wall, floor, or ceiling) is connected to the outdoor unit via a set of connectors:

  • Cables for power.
  • A line set, which consists of tubing for liquid and gaseous refrigerant.

Also, a drain line is required to carry condensation to a drainage pipe in your plumbing system.

The design for your ductless A/C system must account for these cables, tubing, and piping. And the best way to install them is to attach them to the exterior of your home.

In an ideal use case for ductless A/C, exterior connections work with the style of your home and don’t interfere with your own approach to design. However, one or both of the following may be true: 

  • Your home has intricate or multiple roof lines in the path between the indoor and outdoor ductless A/C components. In this case, achieving a “neat” look with the connectors could be challenging. They could be more visible, and less straight, than you’d like.
  • You have a historic home, or you prefer pristine architectural integrity. In this case, you may not want any connectors to be visible on the exterior of your home.

In both of these cases, you can still install ductless A/C – but you’ll want to work with an HVAC company that understands design and offers custom solutions. These companies can use interior walls, discreet access points, and outdoor cable covers to minimize the appearance of connectors.

And a Word about Ductless Heating

In this post, we’ve focused on ductless air conditioning as opposed to ductless heating. But in a lot of climates – including ours in western Pennsylvania – you probably wouldn’t make a long-term investment in your air conditioning without also considering your heating at the same time.

So you might be thinking, “All right, I get that ductless A/C is a great supplemental cooling option. But what about heating the same space in cold weather?”

Good question!

Until recently, ductless heating, which is often called a mini-split heat pump, did not perform well in colder temperatures. This is because a heat pump uses outdoor air to create indoor heat. Depending on the model, a ductless heating system could start losing efficiency at 30 or 40 degrees Fahrenheit and shut down completely at 20 degrees.

However, ductless heating technology has advanced tremendously. Today, many manufacturers offer models that operate at full capacity, and deliver reliable warmth, even when temperatures are well below freezing – and even well below zero. For example, Lennox offers a superior mini-split heat pump like this.

So you don’t need to worry about your supplemental cooling option becoming a liability in a Pittsburgh winter. This is no longer true – you can go ductless without worry, no matter the time of year.


We hope this post provided some guidance about ductless air conditioning and put your mind at ease about ductless heating as well. The big takeaway here is “supplemental” – ductless is best when it’s not your single HVAC solution.

However, as you’ve probably gathered, there are a lot of factors at play when considering ductless A/C. These include your preferences, your home, your HVAC challenges, and everyone who lives under your roof.

When you’re ready to bring in the pros for a consult, please contact us any time. We install elegant, top-quality, custom HVAC solutions across the South Hills of Pittsburgh, and we’re ready to install the best one for you. We look forward to serving you!


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