Split system air conditioners explained
A split system air conditioner pairs an indoor air handler with an outdoor compressor, connected by refrigerant lines that carry heat from inside your home to the outside air. The two units sit in separate locations, so compressor noise stays outdoors and no ductwork is needed to move conditioned air through the room.
What does a split system air conditioner actually consist of?
A split system air conditioner is two separate units: an indoor air handler and an outdoor compressor.
Refrigerant lines and electrical wiring run between them, usually through a small hole in the wall. The indoor unit pulls warm air across a coil filled with refrigerant, which absorbs the heat. That refrigerant travels outside, where the compressor and a second coil release the heat into the outdoor air. A fan pushes conditioned air back into the room. Nothing about that process requires ductwork, which is what sets a split system apart from central air. A window unit packs all of those components into a single box wedged into a frame. A split system keeps them separate, so the compressor noise stays outside and the indoor unit can be mounted high on a wall rather than blocking a window.
How do you size a split system for your home?
Capacity is the part homeowners most often get wrong, and it is easy to see why.
A room's square footage is only one input. Ceiling height, insulation quality, window orientation, shading, and the local climate all feed into the same calculation. Leave any of them out and the number shifts enough to matter. A unit sized too small runs without pause, never pulling the space down to the set temperature. A unit sized too large cools the air quickly but shuts off before it has pulled enough moisture out, leaving the room clammy. Both failures get blamed on the equipment, but the equipment is doing exactly what its capacity allows. A contractor walks the space, takes measurements, and runs a load calculation. Picking a capacity from a product description or a square-footage chart is not a safe substitute for that visit.
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