For 2026, MRCOOL delivers 24 SEER2 efficiency, while Zone Air offers 23 SEER2....

https://lilysuniquethoughtss.urbanvellum.com/posts/what-does-single-zone-vs.-multi-zone-mean-for-diy-mini-splits

For 2026, MRCOOL delivers 24 SEER2 efficiency, while Zone Air offers 23 SEER2. The choice comes down to your winter lows: choose MRCOOL for value when temperatures stay above -15°F, or Zone Air Hyper Heat for heating down to -22°F.