For 2026, compare MRCOOL and Zone Air: 24 SEER2 vs 23 SEER2. MRCOOL is best...

https://oliviamaids.com/can-a-multi-zone-diy-system-heat-and-cool-a-whole-house/

For 2026, compare MRCOOL and Zone Air: 24 SEER2 vs 23 SEER2. MRCOOL is best value above -15°F. Need heat in deeper cold? Zone Air’s Hyper Heat runs down to -22°F. Pick based on your winter lows, not just the small efficiency gap.