Everything You Need to Know About Ductless Mini Split Systems

The cooling season is almost here. Now is the time to schedule annual maintenance for HVAC systems. It’s also a good time to reevaluate your current air conditioning setup. Is the unit on its last legs? Did it struggle through last summer, making weird noises, working poorly, and resulting in high energy bills?

With another hot summer just around the corner, it may be a good idea to explore some other options for air conditioning. One option that’s getting more and more popular is a mini-split air conditioning system. For those of you unfamiliar or looking to learn more, here is our guide to everything you need to know about mini-split AC.

What is a Mini-Split AC?

Otherwise known as ductless air conditioning systems, mini splits are an easy, efficient, and highly advanced alternative to the usual AC options. A split air conditioning system is split between an indoor unit and an outdoor unit – hence, the name. A mini-split air conditioning system operates in the same way, except the indoor unit is multiple indoor units.

These units are installed in the different rooms or zones that they’re meant to cool. This allows for varying temperature settings from room to room. Mini-split systems often double as heat pumps with the same ductless convenience.

Before we get into the specifics of how it works, we’ll take a quick look at the components that make up mini-split AC systems.

  • Indoor Unit / Evaporator Coil / Air Handler/Blower
  • Outdoor Unit / Condenser
  • Electric Line
  • Refrigerant Line
  • Drain Line
  • Heat Pump (when applicable)

How Does It Work?

So, how do these components come together to cool your home? Is the system really “ductless?” If so, how can it cool the entire space? Let’s answer these questions by going through the components in more detail.

The indoor units are installed throughout your home. They can be wall-mounted or installed on the floor or ceiling. The small size of these units makes for versatile, easy installation. Each of these units features an evaporator coil, an air handler, and a blower.

Each unit is installed in the room or zone it will be cooling or heating. This is distinct from typical split AC, which has one indoor unit cooling air and delivering it throughout the home via ductwork.

The indoor units are connected to the outdoor unit through suction line sets, delivering pressurized refrigerant and draining condensate. The outdoor unit functions as a compressor, pressurizing the refrigerant and sending it to the indoor unit.

The blower in the indoor unit blows warm air over the evaporator coils. These coils contain the refrigerant, resulting in cool air recirculating through the home. The heat is removed from the indoor air and then travels through the conduit to the outdoor unit, where it is unloaded into the air outside.

A suction line pulls the resultant condensate water out to the outdoor unit, where it is drained in a suitable location. The conduits that connect the indoor units to the outdoor unit only require a small hole in the wall, typically about three inches. Multiple indoor units can connect to the same outdoor unit.

Pros and Cons of Mini-Split AC

Split System Vs. Ducted System

The main difference between these two options comes down to the ducts. Central air conditioning features a single indoor unit, typically installed in the attic or basement of a home. Ducts distribute air from the AC unit to practically every room in the home.

There are advantages to a ducted system. It’s quieter and more reliable than using multiple window AC units, and more efficient at cooling the entire home. It allows for more control over temperatures across multiple rooms at the same time.

However, those same advantages also apply to a mini-split system. Central air relies on ducts, and if they haven’t been installed yet, that’s a drawback. Installing new ductwork is an expensive, inconvenient process. Once installed, the ducts present an issue of their own.

A duct system presents a large opportunity for energy loss. The cool air makes its way from one location through the ducts to every room you want to be cooled. On its journey, a consistent percentage of that cool air escapes the ducts, causing the air conditioner to work harder and consume more energy.

When ducts pass through spaces that aren’t air-conditioned, this is especially problematic. Also, as the ducts age, the percentage of lost energy tends to increase. Ducts can tear, crack, and leak, and seals can loosen and break. This is why keeping an eye on the condition of your ductwork is an important part of HVAC maintenance.

Pros of a Mini-Split AC

Mini-split AC systems offer many benefits. First of all, the relatively small size and versatility of the indoor units make for easy installation. That versatility includes the option to mount them on the wall, floor, or ceiling in various spaces. As stated above, a three-inch hole can accommodate the tubing for the refrigerant line, the drain line, and the electric line.

Up to four indoor air handling units can connect to the same outdoor unit. With two outdoor units, you could potentially have eight different indoor units throughout the home. This would only be necessary for a larger space, though.

The number of indoor units able to connect to an outdoor unit will depend on the size of the space and the size of the units. “Size” of the unit doesn’t refer to physical dimensions – all the indoor air handling units are compact and can be installed inconspicuously. It refers to how much space the AC can functionally cool.

The ease of installation makes mini splits a great option for spaces where ductwork isn’t already installed. The same holds for additions built onto homes, or small spaces where ductwork is unfeasible.

Energy Efficiency

Another advantage of a mini-split AC system is energy efficiency. The units can be remote-controlled, allowing you to program settings to your liking. You can easily set the temperatures to ensure that energy isn’t being wasted on rooms with less activity. It is easy to tailor the system to your specific needs, working wherever you are in the home, and not wasting energy when you’re out of the house.

Central air shares this feature of convenience and control but is ultimately less energy efficient. According to energy.gov, “ducts can account for more than 30% of energy consumption for space conditioning.” While both are more convenient, quiet, and efficient than multiple window units, ductless mini-split air conditioners are the most efficient cooling systems available.

Also, ducts tend to hurt indoor air quality. Mini-split systems make for better air quality, as they forgo the dust and debris that accumulates inside of ducts. The air circulating through your home isn’t filtered through a dusty system of ducts and is cleaner and safer as a result.

Another advantage is the fact these systems can either provide just cooling or both cooling and heating. Mini-split heat pumps are similarly efficient, allowing you to control the temperature from room to room just as easily. Mini-split heating and cooling offer the same convenience of use as an HVAC system – just with greater energy efficiency.

Lastly, mini-split systems often include a dehumidifying mode, unlike the average HVAC system. Operating modes can also include a sleep setting, fan only, and more.

Cons of a Mini-Split AC

As always, greater efficiency comes at a price. A disadvantage of installing mini splits throughout the home is the relatively higher cost. While it’s easier to install due to the small size of the units, the cooling capacity has to compensate for that small size. The higher the cooling capacity, the higher the price.

Fortunately, high cooling capacity doesn’t mean lower efficiency. The cost is reflected in the installation rather than in your monthly utility bills. That cost is generally around 30% higher than the cost of installing a central air system. However, that figure doesn’t include the cost of installing ductwork, which puts the two on a more even footing.

If you already have ducts installed in your home, an HVAC or central air conditioning system may be more cost-effective. This is especially true if those ducts are in newer, better condition.

Also, another edge that central air conditioning can have over mini-split systems is the way that it looks. This is subjective, but some people will prefer not to see the mini-split units. Central HVAC systems are generally less visible, having a built-in quality.

Cost Factors

Here is what factors into the cost of installing a mini-split AC system. The number of indoor units, the size of the space you’re looking to cool, and the cooling capacity of the units all need to be taken into account. The cooling capacity has to do with the SEER (Seasonal Energy Efficiency Ratio) rating and the tonnage of the unit.

Using the Right Cooling Service is Key

If you decide to explore mini-split AC as an option for your home, make sure you go with a reputable contractor or cooling service that has specific experience with mini-split systems. Proper sizing, installation, and maintenance are crucial, and not all contractors are created equal when it comes to ductless systems.

If you’re in South Jersey, reach out to Laury Heating Cooling & Plumbing for your local experts on ductless mini-split air conditioning! If you want to cool a newer space that was built to optimize energy efficiency or an older one without any ductwork, a mini-split AC could be the perfect option for you!

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