Founder | BPI® Energy Auditor Certified Professional
Technical Editor | HVAC Tech at Kearns Heating and Air
Zoned air-handling capabilities and heat pump technology make mini-splits one of the most efficient ways to cool and heat your home
But what if you already have ductwork in your home? Can you still install a mini-split or are you stuck using central air?
Can a Mini-Split Be Used as a Central AC System?
The answer here is: It depends. Mini-split systems are designed to heat and cool small spaces. While this makes them perfect for zoning, they are not ideal for temperature control in large spaces.
If you have a smaller home, a properly sized mini split will likely work for you.
However, if you have a large home with an open floor plan, the mini split might not be able to keep up.
Mini split systems have two main components: the outdoor condenser and the indoor air handler (or head). The outdoor condenser sits outside your home just like a traditional AC unit. The indoor heads are where things are a little different.
The indoor heads come in both wall-mounted and floor-mounted versions. Multiple heads can be connected to a single outdoor condenser. For most homes, mounting the indoor heads high up in a central location provides the best air circulation.
These systems do not have ductwork and rely on the indoor heads to circulate air. For small to mid-sized homes, mini splits can be a perfectly viable HVAC option.
Can a Mini-Split be Connected to Duct Work?
Most mini splits are ductless systems, however they do have options that can connect to your existing duct work. These are called ducted mini splits.
The outdoor condenser is the same but the indoor heads (or air handlers) are different. These ducted air handlers can be connected to your existing system. In this case, you can use the mini split in addition to your existing forced-air furnace or you can run the mini split alone.
If you are truly planning to use a mini split as a stand-alone central HVAC solution, a ducted system is likely to be your best bet. A ducted mini split will be more expensive but it will allow you to run heat to all of the rooms in your home.
A ductless version will be able to heat and cool specific areas but it won’t be able to provide temperature regulation everywhere (like bathrooms and closets). Depending on your home setup, you could even go with a combination of ductless heads and ducted.
However, unless you have a background in HVAC, you will likely need to hire a professional to do the installation.
Frequently Asked Questions
Can a Mini-Split Be Used for Just Cooling?
Mini-splits are heat pump systems, meaning they can be used for heating and cooling, but you can use them for AC only.
Mini splits work using heat transfer. They use refrigerant (much like a traditional AC unit) to move heat from one area to another.
On cooling mode, they take the warm air from inside and move it outside. On heat mode, they find ambient heat in the outdoor air and move that heat indoors.
Because the mini split is not “creating” heat but rather finding it in the air, it works more efficiently than other HVAC options that rely on combustion or electric heat.
Can a Mini Split Work in the Winter?
Yes! If you live in a cold climate, you’ll want to make sure your new mini split unit is rated for low temperatures before you install it.
While a little more expensive, these units can find heat in the outdoor air even when temperatures drop to -15 degrees Fahrenheit. While they won’t be as efficient in those temperatures, they will still be able to provide you with heat.
Are Mini Splits Loud?
No. In fact, they are so quiet that it can be difficult to tell when the fan is running unless you are standing right there.
The average mini split head is around 32 decibels. Compare that to window ACs at 56 decibels and box fans at around 65.
How Long Will a Mini Split Last?
They have a similar lifespan to a forced-air furnace. Around 15 years is a good average. If you are lucky, you might get 20 years out of it.
Preventative maintenance and regular tuneups go a long way in maintaining HVAC equipment. It’s a good idea to have your system serviced by an HVAC tech every other year.
What Kind of Maintenance is Needed for a Mini Split?
These systems are pretty easy to maintain. For the ductless systems, there are filters in the access compartment that need to be cleaned every 4-6 weeks. These can be easily rinsed off in the sink.
During the summer months, check the outdoor condenser for a buildup of grass clippings and debris. If it is dirty, take a garden hose and rinse off the coils. That’s it.
