Front view of a new construction home with lumber still in the front yard

Mini-splits are getting more attention from the mainstream media these days because people are demanding more efficient heating and cooling technology in their homes.

When embarking on a new construction project, you have a blank slate to install whatever heating and cooling system you choose. Having so much freedom can be intimidating at first because many people worry about making the wrong choice.

But fear not. If you’re embarking on a new construction project and wondering what the best heating and cooling option is for your new home, you’re in the right place.

This article will walk you through the pros and cons of installing a ductless mini-split, so you can choose the right unit for your new home.

Why Would You Want a Mini-Split in Your New Construction Home?

A new home offers a blank slate to choose whichever heating and cooling system you prefer. Mini-splits are an excellent option because they don’t need ducts, are highly efficient and controllable, and will lower your running costs over the long run.

If the installation of a mini-split has piqued your interest, you’ll want to read the rest of this article. It explains how mini-splits work, their benefits, and some of their limitations and things to look out for before taking the plunge.

Notebook at the ready? Let’s go!

What Is a Mini-Split?

Mini-splits are permanently installed systems that provide heating and cooling for the building in which they are installed. They operate in a similar way to a traditional air conditioning unit but have the advantage that they can also provide heating and cooling.

Mini-splits consist of two units; an outdoor unit housing the compressor and an indoor unit known as the air handler or condenser that directs warm or cool air into the living areas inside the building.

The two units are connected by refrigerant lines that convey refrigerant between them to facilitate cooling and heating.

An illustrated diagram of how a ductless mini-split system functions

Mini-splits do not require ductwork to convey conditioned air around the building. Instead, they have an air handler unit in each room (or zone) to heat or cool.

How Does a Mini-Split Work?

The inner workings of a mini-split may seem complicated, but they use the same technology as the humble refrigerator. As a result, the internal mechanisms of both machines are remarkably similar.

The Flow of Heat in a Mini-Split

When a mini-split is in cooling mode, it collects heat from inside the building and moves it outside. When in heating mode, heat from outside is transferred inside, where it is emitted via the air handler unit to warm the building.

We all know intuitively that heat flows naturally from warmer to cooler locations. For example, this happens when the outside of your coffee mug heats up and burns your fingers. The hot liquid transfers some heat into the cooler ceramic of the mug.

Eventually, the mug gets hot as well—and so do your fingers. Ouch!

The phenomenon of heat only moving from hotter to cooler locations in the natural world was first described in 1850 by Rudolf Clausius and William Thomson (Lord Kelvin). They were the first to state the basis for the second law of thermodynamics: “heat does not spontaneously flow from a colder body to a hotter body.”

So, if heat naturally only flows from hot to cold, how does a mini-split pull off the trick of moving heat from the cold side of the system to the hot side?

The answer lies in the refrigeration cycle. The refrigeration cycle is the scientific concept that describes refrigerant fluid flow through a mini-split heat pump, an air conditioner, or a fridge.

The Refrigeration Cycle Used in a Mini-Split

The refrigeration cycle is comprised of four main steps, all of which manipulate the refrigerant fluid to take advantage of its thermodynamic properties to move heat against the natural direction of flow.

These four steps are:

  1. Compression – refrigerant enters the compressor as a low temperature, low-pressure gas and leaves at a higher temperature and pressure before passing on to the condenser.
  2. Condensation – refrigerant in vapor form enters the condenser at high temperature and pressure. As it condenses, the refrigerant releases heat, which is emitted via the condenser coils.
  3. Expansion – the refrigerant passes through an expansion valve, which causes a sudden pressure drop, resulting in the refrigerant suddenly boiling and producing a 2-phase mixture of vapor and liquid that continues its journey towards the evaporator.
  4. Evaporation – the last step is the evaporation of the low temperature, low-pressure refrigerant liquid. As the refrigerant evaporates, it absorbs heat from the air being blown across the evaporator coils in the unit, which causes a cooling effect on the air.

After step four, the refrigerant is passed to the compressor, from which the cycle starts all over again.

The outdoor compressor component of a ductless mini-split
The external compressor unit of a mini-split system

When a mini-split is in heating mode, the condensation step happens inside the building, whereas when it is in cooling mode, the indoor unit serves as the evaporator.

The transition between heating and cooling is achieved using a reversing valve that reverses the refrigerant flow around the system.

Refrigerants Used in A Mini-Split

As you can tell from the explanation above, the refrigerant is extremely important to the operation of a heat pump and makes it possible for heat to be transferred from the hot side of the system to the cold side.

A technician adjucts the pressure on a refrigerant tank being used in a mini-split system

The refrigerant is a special fluid with a low boiling point and has other critical thermodynamic properties that allow it to be used safely and efficiently in the mini-split.

Refrigerants are a big topic in themselves, so we won’t discuss them in-depth, but it is worth talking briefly about them because some can seriously adversely impact the environment.

Most people are environmentally aware these days and will be keen to avoid using refrigerants that could cause harm to the planet.

Early refrigerants were known as HCFCs, or hydrochlorofluorocarbons, which performed well for heating and cooling purposes. Still, they damaged the environment, causing global warming and depleting the ozone layer in the atmosphere, which let through too many of the sun’s harmful rays.

Modern refrigerants have improved their eco-friendliness without losing performance, so this is less of an issue nowadays.

However, the potential environmental harm that refrigerants can cause is something to be aware of when selecting a mini-split, so you can tell yourself you are doing your part to safeguard the environment.

If you’re interested in learning more about the different types of refrigerants, we’ve put together a rundown you can read of the best and most affordable eco-friendly refrigerants.

Benefits of a Mini-Split for a Newly-Constructed Home

There are some essential advantages to using mini-splits in a new home, including potential cost savings and greater efficiency.

However, to ensure you get the most from these benefits, you need to understand how to set things up to take advantage of them fully.

Let’s consider some of the key benefits of a mini-split.

Mini-Splits Do Not Require Ducts

This plus is a big one, often pointed out by people for retrofit projects, because there is no need to retrofit expensive ductwork, which is very costly and disruptive.

But even in a new construction home, there is an advantage to not needing to install ducting throughout the house.

Installation Costs of Ducting

The cost of building a home rises with increasing floor area. The more square footage you have, the higher your overall cost of building will be, so it makes sense not to take up valuable space with ducting that requires additional crawlspace and access routes to allow servicing and repair work to be carried out.

Duckwork that's part of a rigid duct mini-split near a building's ceiling

The ducting has a capital cost associated, which can mount up, particularly in a large house. On top of that, you need to pay for it to be installed (or spend time doing it yourself).

According to HomeGuide, new ductwork installation or retrofitting costs between $2,400 and $6,600. Compare those costs to the cost of cutting a small hole in the wall for a mini-split, and it’s a no-brainer that they will cost less to install.

Installing a mini-split system is so easy and efficient that you can even DIY the project if you really wanted to. Of course, w’d still recommend hiring a team of professional technicians, but you can’t exactly DIY a ductwork project.

Servicing and Maintaining Ductwork

In addition to the space they can take up and the installation cost, ducts have an ongoing servicing and maintenance requirement.

Over time, ducts develop leaks. This deterioration lowers the efficiency of your system and increases the running costs. Even if your ducting doesn’t leak for a long time, it will still require cleaning and checking to ensure it works satisfactorily, which costs money.

According to HomeGuide, here are the costs of ductwork replacement according to the square footage of your home:

  • $1,400 to $3,400 for a 1,000 to 1,500-square-foot home
  • $2,100 to $4,500 for a 1,500 to 2,000-square-foot home
  • $2,800 to $5,600 for a 2,000 to 2,500-square-foot home
  • $3,500 to $6,700 for a 2,500 to 3,000-square-foot home
  • $4,200 to $7,800 for a 3,000 to 3,500-square-foot home
  • $4,900 to $9,000 for a 3,500 to 4,000-square-foot home

If those numbers haven’t made it clear yet, maintaining ductwork certainly doesn’t come cheap. This is one of the ways a ductless mini-split will save you money. There are no ducts, so you will need no such repairs or maintenance.

Ducting Is Less Efficient

According to the US Office of Energy Efficiency and Renewable Energy, a typical ducted system will lose between 25-40% of the heating or cooling energy put out by the central heat pump, AC unit, or central furnace.

That’s a lot of energy to lose and illustrates the importance of having your ductwork hermetically insulated. For further information on air duct insulation and problems that you might run into, read our article on the subject.

If you send your cooled air through a network of ducts that pass through a hot attic, you will lose efficiency no matter how well-insulated your ducting is. And that’s before you even consider the potential for air leaks from the ductwork, which will make matters considerably worse.

It will also take significant energy to blow the air through the network of ducts with the main fan because of the unavoidable energy losses in ductwork, mainly as the air flows around bends and through constrictions.

Compare that to a ductless mini-split, which blows air directly into the room from the air handler, and it stands to reason that you will get more efficient cooling and cheaper utility bills with a mini-split than a central air HVAC unit.

A homeowner sits at a desk against a wall below a mini-split's head unit near the ceiling

Considerable Monetary Savings 

Rocket Mortgage states that the national average to build a house is $282,299. The average range can be as low as $114,209 and as high as $450,824.

If yours is an 800-square-foot house, you might pay only $80,000 for construction. But, on the other hand, a 5,000-square-foot home would cost a cool million. 

That’s only to get your house built, by the way. You still have to get all the fixtures, appliances, and features added, and none of that comes cheap. 

By reducing your energy usage by upwards of 30% and even as high as 40% in some cases, you will save significant cash on your utility bills with a mini-split. 

We once again refer you to this energy savings calculator so you can determine precisely how much money you’ll save. You can input your region (the US is split into five areas by temperature), your cooling capacity in Btu, your current SEER rating, and the rating of your new mini-split.

Let’s say you’re in region three (the central US), and your electric rate is 12 cents per kilowatt-hour. Your air conditioning capacity is 18,000 BTUs. Unfortunately, your current cooling solution has a SEER rating of 14, which is not that good.

Your new mini-split will have a SEER rating of 22, which is much better.

Your annual savings on your utility bills would be $7,866. Over five years, you’d save $39,339. After ten years, it’d be $78,660, and over 15 years, your savings would amount to $117,990.

Everyone wants more money in their pockets. You’ll enjoy those savings immediately with a ductless mini-split for your new construction home

There are no thousands of dollars wasted on ductwork installation or years of overpriced utility bills—you can begin recouping money from month one. 

That’s an incredible feeling! 

Mini-Splits Are More Targeted and Controllable

Mini-splits blow conditioned air directly into a room via the air handler (also known as a head unit), heating that space to the desired temperature.

Homeowners can control the temperature by setting the temperature on the head unit using its thermostat, which often comes integrated with the remote control for the system.

A homeowner on her living room couch points to a ductless Mini-split heat pump on the wall above the couch

Mini-splits can heat more than one room, and several rooms can be grouped together in a “zone” heated by a single head unit.

It’s also possible to run multiple head units in different rooms from a single outdoor unit. Each head unit would allow the temperature in their respective room to be controlled independently.

It is ideal if Grandma is staying in the guest bedroom and needs it to be a few degrees warmer than the rest of the house. You could even heat Grandma’s room while cooling the rest of the house simultaneously.

Compare that to the relative inflexibility of a ducted central air system, which provides air at the same temperature to all house areas, and the benefits of a mini-split are apparent.

Scalability If Your Home Grows 

You’ve long since moved into your new construction home, and you’re getting quite cozy there. But, feeling complacent, you’re beginning to get the itch to expand on what you have. 

If your home featured a traditional HVAC system, adding a new room or several would pose a severe problem. You’d have to install extra ducts that feed into the new spaces. 

You’d probably have to upgrade your heater or air conditioner to deal with the increased capacity. In addition, you’d expect enormous HVAC replacement costs, installation fees, and higher utility bills as your heating and cooling needs go up.

A mini-split system is far more scalable. You can include at least four indoor air handlers per compressor. And if you need to add more head units, you could always install a second compressor.

This freedom to grow and the ease of upgrading your mini-split system will allow you to create the dream home you’ve always wanted! 

Some Things to Consider About Mini-Splits

While mini-splits are an excellent fit for new construction homes, a few of the potential drawbacks of having this type of system is worth mentioning.

Aesthetics of Mini-Splits

We happen to think that modern air handler units are a sleek design that looks good hanging on the wall. However, we are prepared to accept that not everyone has the same taste, and some might find the head units obtrusive or perhaps even plain ugly.

A ductless mini-split in the corner of a room below the ceiling

If you are one of those who can’t stand to look at a wall-mounted unit, you could look at a ceiling cassette, which fits flush with your ceiling and is very discreet—perfect for those who don’t appreciate the looks of a wall mount unit.

Mini-Splits in Large Homes

Depending on your home’s size, you might need multiple head units to heat and cool your home. Typically, up to about five head units can run from a single outdoor unit, which could cover five zones in your home.

If you need more capacity than that, you’re probably better off with a ducted system, which will have better range and ensure that the air throughout your home is adequately conditioned.

Initial Cost of Mini-Splits

Although mini-splits should be cheaper to maintain and operate, they are more expensive to buy in the first place.

A typical mini-split is around 30% more expensive than a traditional central air unit.

If you’re planning on staying in your new home long-term, this initial investment will be worth it, but if you think you might move in a couple of years, you’ll probably want to think more carefully about this before spending your money.

For more information about the cost of a mini-split, why not read our article on the subject here?

Final Thoughts: Mini Splits in a Newly-Constructed Home

Mini-split systems are becoming increasingly popular in the US, and with good reason. They are highly efficient and capable of heating and cooling your home precisely, with zoning allowing for different temperatures in different parts of the house.

Mini-splits do not require ducts. Instead, they blow conditioned air directly into the room via a head unit.

The absence of ducts removes all the headaches of maintaining ductwork, repairing leaks, and losing up to 40% of the heating and cooling energy via ducting.

No ducts to install also means you save money on that part of the project, although if your home is substantial, you might be better served by a central, ducted system.

Mini-splits do have a relatively high initial purchase cost, and some people don’t like the look of the interior air handlers.

If you’re okay with the aesthetics and willing to invest some money upfront to create long-term saving, a mini-split system could be just the thing you need for your newly constructed home.

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