Central air conditioners come in two form factors: split systems or packaged units. These systems have significant differences and there are pros and cons associated with each.
Split Systems
These systems consist of two main parts: a metal cabinet that sits on a concrete slab outdoors and another cabinet that is installed inside the building, hence the term “split.” The indoor cabinet may be inside a closet, basement or in an attic and will often include a furnace. The indoor and outdoor parts of the split system are connected to each other via a refrigerant line.
The outdoor cabinet houses the compressor and condenser, while the indoor cabinet houses the evaporator.
Split systems have the potential to be far more efficient (as high as 25 SEER), though installation involves two units instead of one like with a packaged unit. Two units may be more difficult to install than one; it’s also important to note that unlike a packaged unit, a split system cannot be charged until it’s installed. Homeowners should also note that proper installation is crucial for optimal performance. If a split unit isn’t installed properly, this can severely reduce its lifespan.
Packaged Units
The air conditioner’s main components like the evaporator and condenser are all in one cabinet, and are thus “packaged.” Most of the time, the cabinet is located somewhere outside the building, usually on the roof. In some cases, a packaged unit will include electric heating coils or a natural gas furnace.
Since packaged units are installed outdoors, installation is easier and they save on space in the building. Packaged systems may also work better once installed since they’re assembled in a controlled factory environment and come pre-charged with refrigerant; both factors can ensure optimal function once they are installed. However, their efficiency potential is much less than that of split systems (15 SEER at most). Another drawback comes from the fact that packaged units are placed in a harsh environment; the elements along with wild animals such as raccoons can cause problems. Animals can chew on wires or nest in the cabinet.
Costs
Price could be considered another factor. Packaged units are usually slightly more expensive than split systems but since the installation of split systems is more labor intensive, they both wind up costing roughly the same overall. A split system may be less expensive if the home is already equipped with a furnace and the property owner is replacing an older air conditioning unit.
When choosing between the two, the determining factor may be the building in which the system is to be installed. While larger and newer buildings may have room for the indoor part of a split system, a packaged unit may be the only option in a smaller or older one.