Mini split systems make good retrofit add-ons to houses and can also be a good choice for room additions where extending or installing distribution ductwork is not feasible. Mini splits have no ducts, so they avoid the energy losses associated with the ductwork of central forced air systems. Duct losses can account for 30% of energy consumption for space conditioning.

Their compact size allows for greater flexibility in temperature zoning and they run quieter than central air conditioning systems. Ductless systems are more efficient than central systems and have a higher energy efficiency rating.