Split System vs Package Unit
The two main types of central AC compared — how to identify yours and understand the differences.
What's a Split System?
A split system is the most common type of central air conditioning in the United States. It has two main components: an outdoor condenser unit (the large box with a fan, usually on a concrete pad beside your house) and an indoor air handler (typically in a closet, attic, or garage). These two units are connected by copper refrigerant lines that run between them.
The outdoor unit contains the compressor and condenser coil. The indoor unit contains the evaporator coil and blower fan. Together, they circulate refrigerant to remove heat from your indoor air and release it outside.
What's a Package Unit?
A package unit(also called a “packaged unit” or “rooftop unit”) combines everything into a single outdoor cabinet — the compressor, condenser coil, evaporator coil, and blower fan are all in one box. It connects to your home's ductwork through a wall or roof penetration.
Package units are very common in Arizona, where they're often mounted on the roof of single-story homes. They're also popular in manufactured/mobile homes and commercial buildings.
Side-by-Side Comparison
| Feature | Split System | Package Unit |
|---|---|---|
| Components | 2 units (indoor + outdoor) | 1 unit (all-in-one) |
| Location | Outdoor on pad + indoor | Outdoor (ground or rooftop) |
| Efficiency | Up to 22+ SEER | Up to 17 SEER |
| Noise (indoor) | Quieter | Can be louder |
| Install complexity | Moderate | Simpler (one connection) |
| Common in | GA, FL, NC (Southeast) | AZ, TX (Southwest) |
How to Identify Which You Have
You have a Split System if:
- Outdoor unit on a concrete pad beside the house
- Separate indoor unit (closet, attic, or garage)
- Copper lines run between indoor and outdoor units
You have a Package Unit if:
- Single large unit on the roof or ground
- No indoor unit — ductwork connects directly
- Common on single-story AZ homes
Still not sure?
Use our Dataplate Scanner— snap a photo and we'll identify your system type instantly.
Important: Replace Like for Like
When replacing your AC, you should generally replace with the same system type. A split system should be replaced with a split system, and a package unit with a package unit. Switching types requires significant ductwork modifications and additional labor — it's rarely worth the cost.
The exception is if you're doing a major renovation or building addition that changes your home's layout. In those cases, your contractor may recommend a different system type. Our free jobsite inspection will confirm the best option for your home.
Keep Learning
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SEER Ratings Explained
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