Final answer:
Variable-speed compressors, single-stage compressors, and advanced air filtration systems are innovations found on new high efficiency units.
Step-by-step explanation:
One of the innovations that may be found on new high efficiency units is variable-speed compressors for precise temperature control. These compressors adjust their speed according to the cooling needs, which can lead to energy savings and improved comfort.
Another innovation is the use of single-stage compressors for consistent cooling. These compressors operate at a fixed speed and provide a constant level of cooling without fluctuations. Lastly, new high efficiency units often come with advanced air filtration systems that include features such as HEPA filters and air purifiers to improve indoor air quality.