What is a split system, and is that what I have?

The Two Halves and What Each One Does

A split system is named for exactly what it is: the equipment is split into two connected pieces instead of built into one box. Outside, the outdoor unit houses the compressor, which pressurizes refrigerant and is the closest thing the system has to an engine, along with the condenser coil and a fan that pulls outside air across it to release heat.

Inside, the air handler holds the evaporator coil, where heat and humidity actually get pulled out of your home's air, along with the blower that pushes air across that coil and out through the ductwork to every vent in the house. Refrigerant lines run between the two halves, carrying refrigerant back and forth as it changes from liquid to gas and back again, and low-voltage wiring connects both sides to the thermostat that tells the system when to run.

A disconnect box mounted on an exterior wall near the outdoor unit is usually part of this setup too, a small panel that lets power to the outdoor unit be cut for service. It's a useful landmark, but not a conclusive one: the disconnect box tells you where the power comes in, but it doesn't tell you which kind of system you have, since a packaged unit outside has one too. What settles it is whether ducts leave that outdoor cabinet, and whether there's separate equipment inside the house.

Spotting a Split System at Your Own House

If there's a unit outside your house with a large fan on top that runs whenever the AC is cooling, and inside there's a separate cabinet, often in a closet, garage, or attic, with ductwork branching out from it toward the vents in every room, that's a split system. It's by far the most common setup in Southwest Florida homes.

A ductless mini-split is technically a split system too, just without ducts: one outdoor unit connected to one or more indoor wall-mounted heads instead of an air handler feeding a duct network. The core idea, compressor and condenser outside, coil and airflow indoors, stays the same either way.

The Less Common Alternative: Packaged Units

A packaged unit holds everything, compressor, both coils, blower, and fan, inside one single cabinet, usually set outside on a pad or occasionally on a roof. There's no separate indoor air handler because there's nothing to split; the whole system lives in one box, with ductwork running from that box into the house.

Packaged units show up less often in a typical Southwest Florida house, more commonly where there's no good spot for an indoor air handler, like some manufactured or mobile homes. If your only visible equipment is one single outdoor cabinet with ducts running from it and nothing separate inside, that's likely what you have instead of a true split system.

Why the Split Design Won Out for Most Houses

Keeping the compressor and condenser outside means the loudest, hottest parts of the system aren't sitting inside a closet or attic near living space. It also means ductwork can be routed efficiently from a central indoor air handler to every room, something a single outdoor cabinet can't always do as cleanly depending on the house's layout.

It's also useful to know before a repair call: the indoor half and the outdoor half fail differently, and knowing which one you're looking at, and whether your home even has a true split system versus a packaged unit, helps a technician get to the right diagnosis faster. If something's off with either side, AC repair starts with figuring out which half of the system the problem is actually coming from.