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

What is a ductless mini-split? More importantly, why should you care?

If you’re looking for flexible heating and cooling options for individual rooms in your home, mini-splits can be the perfect fit.

Ductless systems tend to be more well-known in areas of the countries with more buildings that lack central heating and cooling. The majority of homes in the Midwest have ductwork throughout the home. As a result, many homeowners aren’t as aware of this option.

I’m here to help with that. I’ve been working with mini-split for years, and have seen hundreds of ductless installations. In this article, I’ll explain what a mini-split is, how it works, and why it’s different from traditional HVAC systems. Most importantly, by the end you’ll have the information to decide if it’s the right system for you.

What Is a Ductless Mini-Split?

A ductless mini-split system does not need air ducts to operate. A traditional air conditioner will distribute air throughout the home from a single unit. A mini-split indoor unit will service a single room or area, with each unit using a separate fan and evaporator coil.

In a less technical sense, mini-splits are a flexible solution for many homes. They are hyper-efficient heating and cooling units that can control the temperature in hard-to-reach areas.

The term “split” refers to the fact that there is still an outdoor and indoor unit as part of the system. This is in contrast with a “packaged” system, which has the heating and cooling equipment in a single outdoor unit. And of course, “mini” refers to the fact that the individual units, or “heads” are smaller than traditional A/C or furnace equipment.

What are some of the areas where you’ll traditionally see mini-splits in action? Let’s look at some of them:

1. Garages. It’s illegal to put ductwork in garages due to potential safety issues. I use my garage as a workstation for home projects year-round. It would be miserable if it were freezing or too hot when I work. A ductless system allows me to control the temperature in the garage throughout the year.
2. Master Bedrooms. Often, these are the furthest rooms from a central heating and cooling system, and they suffer as a result. If your master suite isn’t being properly heated or cooled, sometimes a ductless solution is preferable to modifying the home’s ductwork or replacing the existing system.
3. Finished Basements. Did you just turn your basement into the perfect party room? It’s probably too cold most of the time, and too hot when you get a bunch of people down there even in the winter months.
4. Attics/Guest Rooms. Similar to the basement, if you have a usable room on the upper level of your home, but it lacks air ducts traveling to it, you’ll often see mini-splits fill the void.
5. Slab Homes. Without a basement to house a larger air conditioner and/or furnace, these homes often lack good heating and cooling options.

Other features of ductless mini-splits include the following:

• They remove humidity. The evaporator coil in the unit will collect condensate, which drains out of your home. However, the reverse isn’t true. They can’t add humidity to a home.
• They filter your air. While the filtration isn’t always as robust as that of a whole-home system, cleanable filters in ductless systems will catch particulates to help keep your air clean.
• Many ductless systems are made by just a handful of manufacturers. This is beginning to change as the market learns about this exciting technology. This fact doesn’t mean all systems are the same, though. As we’ll see, there is a lot of variance in system types, and how they are installed matters as much or even more than the equipment itself.

Ductless systems need regular maintenance and service, just like a full HVAC system. Their smaller size does not mean there is any less need to maintain the equipment.

How Does a Mini-Split Work?

Ductless mini-splits can always cool your air. Some models can also heat your home.

The heating/cooling combo systems function just like a heat pump, in that it’s run based off of electrical power. This makes the equipment very efficient, as we’ll discuss shortly.

Cooling-only units are rare in parts of the country that have a full four seasons of weather. Because it functions like a heat pump, rather than generating heat to distribute through your home, it’s gathering heat from the outside to move into the home. This seems counterintuitive during the winter months. How can the system find heat outside when it’s freezing?

Despite how it feels to us, there is still heat in the air to absorb, and the technology can produce results even in these colder temperatures.

The other major factor in a mini-split system is how many indoor units, or heads, it has. A single outdoor unit can travel to up to eight indoor heads, though residential systems generally feature fewer than this.

This is one of the advantages of a ductless system. By having multiple heads, each functioning separately, you can use only what you need to keep you or your family comfortable, and no more.

Say you are in a dorm area with two bedrooms. This is a common type of building to see ductless systems in. One person wants it to be 74 degrees. Another wants it to be 68 degrees. Who wins?

They both do. Each can control the temperature in their room accordingly. This is also one of the main advantages mini-split systems have over central heating and cooling. Those larger systems can often service a whole home better, but don’t have the same level of granular control.

What Types of Mini-Splits Are There?

We talked about having multi-unit mini-split systems, but these are usually going to be the same type of units. Ductless systems have even more variety than this.

You’re probably most familiar with the wall-hung variety of mini-split that sits at eye level or above. However, these units can also rest along the floor of a room, or they can heat and cool through ceiling cassettes.

There are also limited options for ducted systems. For example, you can fit an air handler into some attics or crawl spaces and run ductwork to a particular area of the home, and pair it with a mini-split. This can be for things like home additions that aren’t in the same air duct system as the original house.

Residentially, ductless systems go up to 4-5 tons, which is a measurement of how powerful an outdoor unit is. A single-head mini-split that’s intended for a single room or area might only need a 0.5-ton outdoor unit, but a five-head split would require something in the upper tonnage range.

What Parts and Service are Different From Central Air?

Parts are unique to most types of HVAC equipment, so ductless systems aren’t unique in that regard. However, a few items separate them.

The main filter on a mini-split can be removed, washed, dried, and re-inserted by the homeowner. However, cleaning other internal parts needs to be handled by a licensed service technician, who will have the equipment and materials needed to handle the process thoroughly and safely.

The filters also don’t catch the same level of germs or allergens as many whole-home air filters. There are carbon filters and small air purifiers that can be added to most systems that handle this function, but the carbon filters need to be replaced periodically or they will stop functioning efficiently, and any air filter will service a smaller area than a whole-home system, much like the mini-split itself.

Mini-Split Efficiency & Lifespan

Now we’re getting to the good stuff. Efficiency is where ductless systems can shine.

I want you to think about the gas mileage on your car. The better the gas mileage, the cheaper it is to drive it consistently. Over the life of your vehicle, this is going to save you thousands of dollars if you have an efficient car.

The same is true of HVAC systems. Many people have heard of SEER Rating, which stands for Seasonal Energy Efficiency Rating. It’s a calculation of how much energy it takes to cool your home to a certain degree. For heating, the acronym is HSPF, or Heating Seasonal Performance Factor.

Whole-home air conditioners can typically get up to about 22-23 SEER. The cooling in a ductless mini-split can be over 30 SEER! The same is true for HSPF, where ductless systems are among the most efficient machines on the market.

The primary reason for this is that mini-splits use inverter technology and a variable-speed compressor. The equipment takes high-voltage electricity coming in and converts it into DC voltage. This means it can use less energy to do more work.

The compressor’s variable speed also means that the airflow is matched to the temperature. Much like a dimmer on a light, it has more than an “on/off” switch. What this means is that it’s only using as much energy as it needs. By contrast, on most standard A/C units you have only one or two speeds, so the machine turns on and off more often.

Mini-splits also come with room sensors to gauge temperature and hot or cold spots. In this way, they can automatically adjust to stay at a certain comfort level.

So your gas mileage, so to speak, is going to be as good or better than a full HVAC system. The downside, of course, is the smaller area it covers, but on a one-to-one basis in the zone a mini-split heats or cools, it will be very efficient.

This is the highest level of technology built into an HVAC system. However, it still requires regular maintenance to continue running efficiently. Properly maintained, you can expect 12-15 years on average from your system, or more on occasion. Unfortunately, people tend to forget about mini-split maintenance more often than with larger systems, so many systems last far less than this. Make sure you’re maximizing your investment by taking care of it!

Is DIY a Good Option?

You’ve probably seen the commercials that talk about purchasing and installing your own ductless system. While any decision about your home heating and cooling is ultimately yours to make, there are several risks to be aware of with this option.

With a licensed, trained HVAC contractor, you’re going to have equipment that’s installed to manufacturer code, tested, and commissioned to ensure proper efficiency, and maintained for the life of the system to make sure it stays efficient.

By contrast, you have none of those assurances with a self-installation. The equipment won’t be warrantied, finding parts can be a hassle (or impossible) in case it breaks down. If you have to turn to a contractor for repairs, there’s no guarantee they’ll be able to secure parts either, which are often specific to the make and model of a unit.

Homeowners often underestimate the complexity of installations as well. There are elements of carpentry, electrical work with high-voltage wiring, working with flammable and combustible materials, and the use of open flames for brazing (a form of welding).

Beyond that, much of the equipment required to perform each of those tasks is highly specific and sometimes very expensive. Do you have all the proper tools, know how to use each, and want to buy them for a one-time installation? Many of the units for sale online for DIY installation don’t come with all of the proper tools, and sometimes don’t include all primary parts required for it to fully function.

There’s a myth that HVAC equipment is much like an appliance: plug it in and you’re good to go. This couldn’t be further from the truth. The skills, training, and tools required to guarantee a responsible installation are not things the average homeowner has.

If an HVAC contractor makes a mistake during installation, it won’t cost you a dime. If you make a mistake, though, there’s no safety net.

At Fire & Ice, we have 12-year warranties on our mini-splits. This is because we have continual training and are licensed to install this equipment. We’re able to stand behind our products to give you peace of mind.

So if you decide to install one yourself, can it work out? Maybe. But we’ve seen instances where the unit lasts less than three years due to poor installation and maintenance, and many others where the efficiency of the system is far less than what it could be.

Stated differently: If it’s less expensive, there’s a reason for that.

What is your money worth to you? If you want to make sure you’re getting the best value for your money, a professional installation is the safest option.

Who Should Consider a Mini-Split?

If you’re building a house and are able to put ductwork in, this is going to be the better whole-home solution. There are efficiency advantages to ductless systems in some situations, but also limitations when it comes to larger environments.

On the other hand, if you have a slab home or older home with no ductwork, the cost of installing ductwork can sometimes exceed the cost of an air conditioner and furnace. If you need heating and cooling for your home in these instances, you should explore both ducted and ductless options.

Who else 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 like 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. Your comfort level will increase dramatically. And installing a mini-split can be the difference between never using a room, and it being your favorite room in the house.

The cost can vary depending on several factors, including the types of heads being installed and how many heads your system has.

Lastly, even if you’re just interested in the cooling properties of mini-splits, always consider ones that both heat and cool. The cost difference is usually minimal, and you can’t retrofit a cooling-only unit to do heating once it’s installed.

Start Here

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. Give us a call today!