Mini split or central air

Central air cools the whole house from one system. It pushes cooled air through ducts to a register in each room. A ductless mini split puts a small indoor unit, called a head, in each room or open area, and runs a thin line set from each head to an outdoor unit. No ducts are needed.

Both cool well. Both can heat, since a mini split is usually a heat pump and central air can be paired with a furnace or built as a heat pump. The real difference is the ducts, and how many rooms you want to control. We cover homes across Los Angeles, and our page on ductless mini split installation explains how we plan a ductless system room by room.

Here is how the two line up side by side.

If the house has ducts. Start by checking them. Good ducts make central air the simplest, tidiest way to cool the whole house, with one outdoor unit and nothing on the walls. Leaking or crushed ducts change the picture. Under California's Title 24 energy code, a new central system usually brings an independent HERS test of the ducts, and existing ducts usually need to test at 15 percent leakage or better. If they fail, sealing or replacing them becomes part of the job. Sometimes duct repair and sealing is all it takes. Sometimes the ducts are far enough gone that a mini split makes more sense.

If the house has no ducts. Many older Los Angeles homes were built with a wall furnace and no duct system at all. Adding ducts means finding room for them in the attic, the crawl space or dropped ceilings. A mini split skips that. The line sets are small and can run through an outside wall, an attic or a closet, so the house stays largely as it is.

If you only need one or two rooms. An upstairs bedroom that bakes in the afternoon, a converted garage or an addition the ducts never reached is a classic mini split job, even in a house with central air.

Attic ducts in the valleys. Many Los Angeles houses run their ducts through the attic. In Woodland Hills, Van Nuys or Santa Clarita, that attic can get very hot on summer afternoons. A leaking duct up there loses cooling before it reaches the room. A mini split has no ducts to leak, which is one reason it does well inland.

Mild winters. Both systems can heat, and in a Los Angeles winter a mini split usually heats the rooms it serves comfortably without backup.

The same rules apply. Installing heating and cooling equipment usually goes through your city's building department, and we handle the permit where one is needed. New equipment made since 2025 mainly runs on R-454B or R-32, for both kinds of system. Check the current rebates at LADWP, SCE or SoCalGas before you buy.

You are choosing between cooling the whole house from one system and cooling it room by room. The questions that decide it are these.

1. Does the house have ducts, and are they worth keeping?
2. How many rooms do you want to cool, and do you use them all at once?
3. Do you mind a head on the wall in each room?
4. Is the furnace old enough that a heat pump should replace it too?

To help you decide, we look at the ducts if there are any, the rooms, the attic, the electrical panel and where an outdoor unit can sit. Then we price the option that fits, and the other one if you want to compare. Our guide to mini split installation cost covers what moves the price of a ductless system, and our page on AC installation and replacement covers central air. When the ductless route fits, our ductless mini split installation page is the place to start.