The Maytag M1200 PSA4BI iQ Drive, Carrier Infinity 21 24ANB1 and Trane XV20i are some highly-rated AC systems. The Amana ASXC18 is also a highly-rated AC system, according to ConsumerSearch.
The Maytag M1200 PSA4BI iQ Drive is Energy Star qualified with a seasonal energy efficiency ratio, or SEER, rating that can reach 25.5 and is quiet with a noise level of 59 decibels. The thermostat has multifaceted programming features, notifies for maintenance and gives diagnostic information. The Carrier Infinity 21 24ANB1 has a SEER up to 21 and runs at a quiet 65 decibels. It is Energy Star qualified and there is an optional thermostat that can be controlled by an Android or Apple smartphone or tablet. The Trane XV20i is Energy Star qualified and has a SEER up to 21.
It has a modulating compressor for temperature control, an air-cleaning module can be added and there is an optional Internet capable thermostat. The Amana ASXC18 has a top SEER rating of 18 and a two-stage compressor for humidity control. It can use smart or standard thermostats.