They don't need it, they just don't get all their rated efficiency, which is much higher than single-speed systems. Single-speed systems commonly have cooling e

They don't need it, they just don't get all their rated efficiency, which is much higher than single-speed systems. Single-speed systems commonly have cooling efficiencies around 10-14 SEER, the Gree Sapphire is 38 SEER. If you ran it at only full power, it'd probably only be 30 SEER.