For homeowners

Types of AC: which one fits your home?

Choose Ducted central (split or packaged) for even cooling throughout the home; Ductless mini-split for homes or parts of homes without ductwork; Room unit (window or portable) for cooling select spaces in a home with no air conditioner.

The right choice depends on whether your home already has ductwork, whether you need to cool the whole home or only select spaces, and whether you want the same system to heat the home too (central and mini-split both come as heat pumps).

How we know: By InstaBids editorial team with AI research agents. · Sources read: 17 October 2026 · Updated 27 October 2026

Central here means ducted: DOE (2016) says a central air conditioner circulates cool air through a home using a system of ducts and registers
Type	Best for	Main advantages	Main drawbacks
Ducted central (split or packaged)	even cooling throughout the home	Also comes as a ducted heat pump, which works like a central air conditioner that also heats the whole house in winter (ENERGY STAR)	In a typical house, about 20 to 30 percent of the air moving through the ducts is lost to leaks, holes and poorly connected ducts (ENERGY STAR)
Ductless mini-split	homes or parts of homes without ductwork	Avoids the energy loss associated with ductwork (DOE, 2016); Works in all climate zones (DOE, 2016); Mini-split heat pumps heat and cool from the same system (ENERGY STAR); Can use multiple head units, mounted on interior walls or ceilings, with one unit outside (ENERGY STAR)	It can be challenging for heat to move through an open doorway, and impossible to move through a closed one (ENERGY STAR)
Room unit (window or portable)	cooling select spaces in a home with no air conditioner	Some window models (U-shaped or saddle-style) let you fully open and close the window the unit sits in (ENERGY STAR)	Improper installation can increase air leakage by as much as 10 percent (DOE, 2016)

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What are two types of air conditioning?

DOE's Home Cooling infographic (2016) names split systems and packaged systems. Split systems are called that "because they are made up of an outdoor unit, which contains the condenser and compressor, and an indoor unit, which is often connected to a furnace or heat pump." In DOE's words, "Systems that have the evaporator, condenser and compressor in one unit are called packaged systems."

A ductless mini-split also has indoor and outdoor parts. ENERGY STAR describes it this way: "a head unit, or multiple head units, are mounted on an interior wall or ceiling, with an accompanying unit outside."

What are the four types of AC?

DOE's Home Cooling infographic (2016) shows these rows under "Types of Air Conditioners": central, room (a window unit or a portable), ductless mini-split and evaporative cooler. This page compares the first three.

The split and packaged systems in the question above both fit the federal definition of a central air conditioner, which, for single-phase, air-cooled units below a set cooling capacity, "may consist of: A single-package unit; an outdoor unit and one or more indoor units".

The evaporative cooler is the one left out here. DOE (2016) says it "cools outdoor air using evaporated water and circulates it throughout the house." For an arid climate, DOE's advice on choosing it adds: "In addition to cooling the air, they add moisture, which can improve comfort." The drawback DOE lists for it in the same table is that it "requires more frequent maintenance and is only suitable for areas with low humidity."

How long do AC units last?

DOE's Home Cooling infographic (2016) gives a life span of 15-20 years for a central air conditioner, 12-15 years for a ductless mini-split and 10-15 years for a room air conditioner (a window unit or a portable). These are DOE's ranges for each type, not a figure for any one unit. The same infographic says annual maintenance can help improve the efficiency of your air conditioner "while prolonging the life of your unit."

What is the most common AC problem?

DOE's Home Cooling infographic (2016) does not rank one problem first. Its panel on common air conditioner problems groups them by symptom: "Your unit isn’t cooling properly," "Your unit isn’t turning on" and "Limited airflow."

One item DOE (2016) lists, without ranking it above the others, is a dirty filter: "A clogged filter restricts airflow through the unit, decreasing its efficiency and reducing its ability to effectively cool the air."

Under a unit that isn’t cooling properly, DOE (2016) also lists refrigerant: "Your refrigerant could be low or leaking. Call a trained technician to repair the leak and recharge the system."

If your priority is...
Priority	Choose
even cooling throughout the home	Ducted central (split or packaged)
no ductwork, and no wish to install a ducted system	Ductless mini-split
cooling select spaces in a home with no air conditioner	Room unit (window or portable)

What does central AC replacement cost?

For central AC replacement prices, see How much does AC replacement cost?

Something already failing? See AC repair or replace: which fits your system?

In Florida: what the code says

All air conditioners that are sold or installed in the state must meet the minimum efficiency ratings of the Florida Building Code-Energy Conservation.

The Florida Legislature, Florida Statutes s. 553.912 Air conditioners (2026 Statutes), read 17 October 2026.

It is the intent of the Legislature that all replacement air-conditioning systems in residential applications be installed using energy-saving, quality installation procedures …

The Florida Legislature, Florida Statutes s. 553.912 Air conditioners (2026 Statutes), read 17 October 2026. The statute states this as the intent of the Legislature, not as a requirement.

… including, but not limited to, equipment sizing analysis and duct inspection.

The Florida Legislature, Florida Statutes s. 553.912 Air conditioners (2026 Statutes), read 17 October 2026. These are the installation procedures the Legislature’s intent statement names.

Notwithstanding this section, existing heating and cooling equipment in residential applications need not meet the minimum equipment efficiencies, including system sizing and duct sealing.

The Florida Legislature, Florida Statutes s. 553.912 Air conditioners (2026 Statutes), read 17 October 2026.

Local rules differ; check your county and city.

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Sources for the facts on this page

U.S. Department of Energy, Energy Saver 101: Home Cooling infographic (2016), government, read 17 October 2026.
ENERGY STAR (U.S. EPA / DOE), Air-Source Heat Pumps, government, read 17 October 2026.
ENERGY STAR (U.S. EPA / DOE), Duct Sealing, government, read 17 October 2026.
ENERGY STAR (U.S. EPA / DOE), Ductless Heating & Cooling, government, read 17 October 2026.
ENERGY STAR (U.S. EPA / DOE), Room Air Conditioners, government, read 17 October 2026.
eCFR, 10 CFR 430.2 Definitions (U.S. DOE), government, read 17 October 2026.
The Florida Legislature, Florida Statutes s. 553.912 Air conditioners (2026 Statutes), statute or code, read 17 October 2026.