All About Mini Split Systems

Sometimes a property owner has a specific area to heat or cool where they don’t want the trouble of doing a complete installation of ducts and registers. In instances like that, the ease and flexibility of adding a mini split AC for that space can be the perfect solution. A mini split AC and mini split heat pump can provide the additional temperature control without the homeowner even seeing much of an increase in their utility bills. As the installer or contractor, a mini split can be a pretty simple open-and-shut installation that doesn’t require ductwork while eliminating other noisy and inefficient alternatives that a customer may consider.

What is a mini split?

A mini split system is comprised of:

  • A single small outdoor compressor or condenser unit
  • One or more indoor evaporator or air handling units
  • Communication cables, power cables, copper tubing and a drain line, all routed through a hole no bigger than three inches

And…that’s it.

Bear in mind that a full-house central air conditioning system or a heat pump requires a lot of ductwork, which can quickly become intrusive. If the system has to be retrofitted into an existing home and the job takes more than a day or two, that’s quite a disruption for the homeowner’s daily living routine.

mini split system

Since mini split systems typically only need to heat and cool one room or maybe two, the need for ductwork is a non-issue. Mini split installation costs are a lot lower than the costs of retrofitting a whole house or even part of one. This is especially valuable when you consider that as much as 30% of the loss of efficiency in an HVAC system comes from losses through the ductwork. If there’s a bigger area that needs heating and cooling, ducted mini split systems can be installed, with a variety of duct configurations.

What are the different types of mini splits?

While mini split HVAC systems all operate on the same principles with the components listed above, there are a few different installation and configuration options:


  • Ceiling mounted units are an individual unit that’s mounted where the wall and ceiling meet. This is a fairly unobtrusive look that keeps the unit out of direct eye-line as one walks into a room.
  • Ceiling recessed mini splits are built completely into the ceiling, with just the register exposed. This is a more complex installation, but has the benefit of just looking like a (fairly large) vent built into the ceiling.
  • Floor mounted installations are set where the wall and baseboard meet. A floor mounted mini split might be more visible in the room, but they have the advantage of blowing air where it’s more easily felt by a room’s occupants (compared to a ceiling mount). The floor mounted option is an especially good idea if heating is a bigger consideration, since heat will rise from the floor and saturate the room more easily.


What are the benefits of mini splits?

  • Flexibility: Along with doing away with a noisy, unsightly window unit, a mini split system can allow a homeowner to set “zones” in the house and fine-tune temperatures room by room. Their flexibility also makes them a great choice for commercial installations such as jobsite trailers, security stations or dispatch offices.
  • Efficiency: Everyone is at the mercy of fluctuations in energy prices, and a mini split system is inherently more efficient than a whole-house central HVAC. There’s no loss in ductwork since the unit delivers air directly into a room, they use a lot less energy than a whole-house unit and many states or cities offer tax credits or utility rebates for installing less energy-hungry HVAC systems.
  • Enhanced air quality: A modern mini split has several stages of air filtration to trap allergens, dust and particulates — and of course there’s no duct system to harbor mold and dust and require regular cleaning.
  • Ease of installation: A mini split only needs a small hole drilled through to the outside, minimizing the risk of bugs or pests infiltrating the home, and of course don’t need ductwork.
  • Quiet: A mini split system is surprisingly quiet, and considerably quieter than conventional window AC units.

How much does a mini split cost?

A mini split system costs less than a new whole-house HVAC installation, but more than a conventional window AC unit. Some of the costs include:

  • $300-1200 in labor, depending on the complexity of the installation
  • A concrete pad for the outdoor compressor/condenser, ranging from $75 to $300
  • Possibly a dedicated electrical circuit (another $250 or so)
  • Possibly an upgraded electrical panel, in older homes ($1000-1200)
  • Refrigerant lines, at about $5 per foot
  • Wall mounts, ceiling mounts or baseboard fixtures ($200-1000)
  • Indoor ceiling cassette, for a completely ceiling-mounted setup, for $500-1500
  • The cost of the outdoor unit itself, ranging from $1000 on up

Many companies offer mini split systems as a complete kit, which can range from about $1200 to $8000 or more. Obviously there are a lot of variables involved with each style of installation and the total cost can vary considerably.

What are the cons of mini splits to consider?

  • Aesthetics: Some homeowners might find the installation of a mini split system to be intrusive, or to be a poor match for the rest of the room’s decor. Then on the other hand, many homeowners who have those kinds of reservations later say that they don’t even notice the unit after it’s been there for awhile.
  • Upfront cost: While a mini split is considerably less expensive than a whole-house unit, it’s also a lot more than a window unit and that can be enough to give some people pause. Then again, when a mini split is figured into the cost of new construction or an addition, it can seem like a real bargain.
  • Regular maintenance: The enhanced filtration of a mini split system means that the washable filter element will need to be serviced monthly. Putting off regular maintenance can mean an accumulation of dust and debris that can disable the unit or can require an expensive professional cleaning.