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(707) 539-4533 |  Sonoma Napa and Marin Counties

updated 5/12/22


While traditional ducted central air systems are still the most common kind of air conditioning, ductless mini-splits are becoming increasingly popular. Mini-splits offer a flexible, compact alternative to standard split system AC units, which appeals to many homeowners looking for a new way to keep cool over the summer. If you’ve never considered adding a mini-split to your home, it’s worth doing a little research to find out if they suit your air conditioning needs.


Mini-split air conditioners work pretty similarly to a regular split system AC. They’re split into two separate units – one with the condenser coil, and one with the evaporator coil. A thin line runs refrigerant back and forth between the two units, and a blower fan in the evaporator unit forces the cool air out into the room. However, where a central air system pushes air through ducts in your home to keep it cool, a mini-split unit just blows cool air directly into the room. While this does mean you’ll likely need multiple evaporator units to cool your home, it also avoids the need for expensive and bulky ductwork in your attic or basement. Many of the benefits of a mini-split system come from its compact nature, although it does come with some drawbacks as well.

We recommend getting in touch with a local HVAC installation company before making a decision one way or the other. There’s certainly plenty of research that you can do on your own, but it’s always a good idea to have your home checked out by a professional before finalizing anything. The best air conditioning system for you will depend heavily on the specifics of your situation. However, it’s smart to familiarize yourself with the pros and cons of any system before discussing it with an installation company. Here’s a little information on mini-split air conditioners that might help with your final decision.

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Advantages of a Ductless Mini-Split System

While ductless air conditioners used to be the province of smaller buildings like garages or mobile homes, more and more homeowners and apartment renters have been installing them in their residences. The technology has advanced significantly, and mini-splits are now an efficient and well-rounded form of air conditioning that can provide benefits to anyone, whether they’re living in a trailer or a multi-story home. Many of the advantages come from the lack of required ductwork, but there are other strengths as well.


Energy Efficiency

Mini-split air conditioners are generally some of the most efficient ways of cooling your home. Anyone who’s ever had an air conditioner knows how much they contribute to your monthly electricity bill, so finding a way to cut down on power usage is a necessity when installing a new system. Some mini-splits achieve greater efficiency through more advanced cooling technology, which we’ll talk about a little later on. However, even the less expensive and advanced mini-split AC units will save you some power based solely on the fact that they avoid ductwork.


Ducts are typically some of the worst offenders when it comes to loss of efficiency in an HVAC system. The action of forcing cool air through a whole system of ducts is inherently power-intensive, so your AC fan has to work especially hard to make that happen even in perfectly functional ducts. Unfortunately, it’s pretty much impossible to keep any ductwork in perfect condition. Air gets caught in corners and bends in the ducts, and small leaks and cracks that inevitably form will cause more air to leak out, reducing the efficiency of the whole system. Ducts can also easily become partially blocked or clogged with dust and other contaminants, forcing your AC unit to work even harder.


By avoiding the problem of ductwork altogether, mini-split air conditioners don’t have to deal with some of the most common causes of inefficiency. In fact, as a general rule, experts estimate that the average ductless system uses between 30% and 40% less electricity than a central air system, saving homeowners a significant amount of money on their monthly power bill. This is one of the primary advantages of a mini-split system, and a big reason why lots of people are switching over.




Besides the reduction in efficiency, ducts also pose a pretty serious space problem. Ductwork can be extremely bulky, and not everyone wants to see all that space in their attic taken up by big metal tubes for their air conditioners. Unfortunately, shrinking the size of the ducts significantly cuts down on the efficiency of the system, so that’s not really an option. If you want a ducted central air system in your house, you’re pretty much stuck with the big bulky ductwork. Some people have more than enough space for the ducts, but others might not want to sacrifice that much room.


The same goes for the units themselves. As the name suggests, central air systems work using a single pair of central air conditioner units. These units have to be pretty big and bulky if they’re going to have enough power to cool down an entire house, so they generally take up a lot of room. You can usually put one of the units outside, but then you’re stuck with this huge metal box sitting by the exterior wall of your house. They also tend to be pretty noisy.


Ductless mini-split units, on the other hand, are very small and can be placed directly on the wall in the room. They’re great space savers and don’t require a whole closet or section of the basement for housing. They also generally run very quietly. If you’d prefer to leave the wall open, there are also some mini-split air conditioners that can be set directly into the ceiling so the air blows straight down into the room. At this point, the units are barely noticeable, which is a huge plus for anyone who lives in an apartment or small house where space is at a premium.


Ease of Repair


Ducted air conditioning systems can be both difficult and expensive to repair. Technicians have to disassemble the ducts and get inside to find the source of many problems, and the units themselves often aren’t easy to access either. You have to also be on the lookout for any leaks or cracks in the ducts themselves, which can lead to air escaping and forces your air conditioner to work harder. It’s just a less convenient system, especially when it comes to initial installation. Installing ducts into your home can take a long time and a lot of money since it generally involves opening up the ceiling to lay down the ductwork.


Ducts also require a certain amount of maintenance. Besides the constant search for leaks, dust and debris can easily build up inside the ducts and cause problems for your air conditioning system. Generally, it’s recommended that you have your ducts professionally cleaned every two or three years, alongside the regular yearly maintenance that air conditioners require. Cleaning ductwork is a difficult process that requires some specialized tools, so it’s not exactly something you can take care of yourself, either.


Ductless mini-split units are generally pretty easy to clean and maintain, and the initial installation costs are pretty low. The units themselves can be somewhat expensive, but installing them is quick and easy. That price is also somewhat offset by the fact that you don’t have to install any ducts, which is also fairly expensive. If your home doesn’t already have ductwork, then the cost of buying and installing a ductless system will often be around the same as a central air system.




For most people, air conditioning is only half of a fully-functioning HVAC system. Unless you live in the deep South or somewhere like Death Valley, there’s a pretty good chance you’re going to need some form of heating as well. Many central air systems require you to purchase and install a furnace to provide heat, which is an extra cost, but mini-splits (as well as some regular split system air conditioners) can usually function as a heat pump as well.


A heat pump functions essentially the same way as an air conditioner, but with one major difference. Instead of putting the cold evaporator coil in the inside unit with the blower fan, a heat pump leaves the evaporator in the outside unit and has the condenser coil inside. Air blowing across the condenser is heated up instead of cooled down before it enters the room. Heat pumps are a simple and efficient way to keep your house warm in the winter without requiring you to pick up a furnace and find somewhere to install it.


Sometimes, adding a heat pump to your existing HVAC system means you’ll have to pick up a new unit and install it. However, many air conditioners, including pretty much all mini-split units, can actually function as both an AC and a heat pump. By reversing the flow of refrigerant, the unit can turn the evaporator coil into a condenser coil and vice versa. All you have to do is flip a switch and the air changes from cold to warm.


Unless you live somewhere with warm weather year-round, the ability to switch between air conditioning and a heat pump is a huge convenience. It also saves you money by allowing you to heat your home without needing to install a furnace or other heating unit.


Built-In Zoning


When it comes to designing a great HVAC system, zoning is one of the most important things any contractor will consider. The word “zoning” is an industry term that refers to the ability to separate different parts of the house and control their temperature separately. With a properly-zoned HVAC system, you could set different temperatures in different parts of your house, or even turn the air conditioning off in certain rooms while leaving it on in others. This can have a pretty huge effect on the efficiency of your system. Even something as simple as leaving the AC on in your bedroom overnight while turning it off for the rest of the house can save you a ton of month every month.


In a central air system, we can achieve zoning through the use of multiple thermometers, vents that can be opened and shut, or even multiple air conditioners. A ductless multi-split system, however, makes zoning pretty simple. Every evaporator unit in a ductless system has its own thermostat that you can set independently, and they each operate individually. The only thing that the condenser unit really handles is the flow of refrigerant to each evaporator unit, so you’re free to set different temperatures on every unit. This generally means that each room in the house can act as its own zone.


This offers a couple of benefits for a homeowner. The first is the energy efficiency that we already mentioned earlier. Leaving the HVAC system on in your bedroom overnight while turning it off in the rest of the house is a great start, but there’s plenty more you can do to really maximize the efficiency of your system. The second benefit is comfort. It’s rare for everybody in a single household to have the exact same temperature preferences, so a properly zoned system means each member of your family can set their own individual thermostat, avoiding potentially heated arguments.


Advanced Tech


Modern mini-split units are often packed with the most up-to-date and advanced technology the HVAC industry has to offer. Zoning is a big one, but there are also plenty of other quality-of-life additions that you’ll find in most mini-split air conditioners. A major one is variable refrigerant flow technology or VRF. These units have variable-speed compressors that can fine-tune the amount of refrigerant flowing through the system at any one time. These units are significantly more energy-efficient than the traditional compressors that have only two options: off and on. This technology, coupled with power inverters that convert AC power from the wall into more easily controlled DC power, can save you a ton of money on your electricity bill.


Mini-splits also have other technology designed to make your life a little easier. Many newer units have smart thermostats built-in, allowing you to program in schedules, set automated parameters, and even control the AC from your smartphone. Mini-split units also usually include humidity controls, dehumidifying your house as it controls the temperature.


While some of this tech won’t necessarily affect the actual functionality of the unit, it does offer plenty of conveniences and quality-of-life improvements that can go a long way towards making your home more comfortable.


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Disadvantages of a Ductless Mini-Split System


While a ductless system certainly offers plenty of benefits, that doesn’t mean it’s perfect for everyone. It comes with its own downsides as well, so it’s important to make sure you’re getting a full picture before you make up your mind one way or the other. Central air systems have been the gold standard in HVAC for decades, and there are plenty of other alternatives as well if you don’t think that a mini-split will work for you. Here are a couple of disadvantages to keep in mind while you’re considering a ductless HVAC system.


Purchasing Cost


This is the biggest thing that gives some people pause when they’re thinking about installing a ductless mini-split air conditioning system. There’s really no way around it – these units are significantly more expensive than standard split system air conditioners, even if you’re choosing lower-end models. The average cost of installing a full ductless system is about $12,000, and that number gets higher as you add more and more units. Even if you’re living fairly comfortably, $12,000 is enough to set your savings back by quite a bit, and it’ll take a long time for the monthly savings on electricity to offset that large initial cost. At a certain point, that old mantra of “you get what you pay for” starts to apply. If you want the advantages that a mini-split system has to offer, you have to be willing to pay for them.


That being said, if you’re living in a home that doesn’t already have ducts installed, the calculus starts to look a little different. It depends on the size of your house and the type of HVAC system you’d like to have, but if you need to install both a central air AC unit and the ductwork to disperse the cold air all throughout your home, then the cost will start to be pretty comparable to buying a ductless system. This is part of why we recommend that everyone talk to an HVAC contractor before deciding on a system. The specifics of your house and what you’ll need to have installed will affect the question of which system is less expensive.


Functionality in Extreme Temperatures


This particular downside won’t apply to everyone, but mini-split systems are infamous for struggling to handle extreme temperatures, especially when the temperature gets very low. This generally isn’t perceptible when the weather gets very hot, but you’ll notice some problems if the winters get especially cold. The coils in each mini-split unit are smaller than a full-sized air conditioner, which means they can be overwhelmed if there’s too much cold air passing through the system.


As a general rule, most mini-split units will work fine until you get down to about 30 degrees Fahrenheit. Once you get below freezing, you’re likely to see a loss of efficiency, and the unit might even turn off altogether if you get below 20 degrees or so. If you live up in the northern parts of the country, especially away from the coasts, this could be a persistent problem all winter. However, this can be mitigated by picking up a unit with a base pan heater that keeps the coils warm even when the air outside is cold. There are also mini-split units that are specifically designed to operate in cold temperatures, although you might start to see problems with them if the summer gets too hot.


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Is a Ductless Mini-Split System Best for Me?


Ultimately, the decision will rest on factors that are specific to you, your home, and the local climate. It’s impossible to make the call based just on articles since we don’t know your exact situation. However, you can always get in touch with an HVAC contractor for help. They’ll be able to look through your home and advise you on the best air conditioner to fit your specific needs, as well as help you pick out a unit and install it for you. We highly recommend not being afraid to reach out and ask for advice from an expert! You can do plenty of research on your own, but you’re never going to have as much knowledge as somebody who’s been in the HVAC industry for a decade or more.


If you live in Sonoma, Marin, or Napa County, feel free to get in touch with Valley Comfort Heating & Air if you have any other questions on ductless mini-split systems. We’re more than happy to share our knowledge with you and answer any questions you might have. If you’re thinking about buying a new air conditioner, we can help you with that too. Our experts are more than capable of taking a look at your home, advising you while you pick out units, and even handling the installation and regular maintenance for you. You can give us a call at (707) 539-4533, get in touch with us through our website, or just come visit our location in Santa Rosa, CA. We’re happy to help you out in any way we can.