The 18RLXS is an 18,000-Btu, 19 SEER, 10 HSPF heat pump. The 24RLXS is a 24,000-Btu, 18 SEER, 10 HSPF unit. The 30RLX is a 30,000-Btu, 16 SEER, 9.5 HSPF unit. Three ductless wall-mount mini-split ...