Is a dual-hose portable AC really better than a single-hose model?

The strongest consensus across specialist communities (r/phoenix, r/hvacadvice, r/AirConditioners) is yes. Single-hose units pull conditioned air out and create negative pressure that sucks hot air back into the room, while dual-hose models use separate intake and exhaust paths for more efficient cooling. Reviewers consistently recommend dual-hose units for anything above roughly 12,000 BTU or for rooms in hot climates.