Dual-hose portable ACs cut energy use 20-40% versus single-hose models by avoiding continuous outdoor air intake

The New Scientist analysis correctly identifies the pressure-driven infiltration flaw but understates measured performance gaps. Field tests in the 2022 ACEEE portable AC study (n=24 units, 30-35°C ambient) found single-hose SEER-equivalent efficiency 22-38% lower than dual-hose equivalents once infiltration was included; the gap widened above 32°C. European Ecodesign labels report only internal heat transfer, omitting this penalty and leaving consumers without data equivalent to the U.S. Energy Star portable AC test procedure that explicitly measures room pressure effects.

Dual-hose units or simple external-intake modifications keep conditioned air inside the envelope. A 2023 Building Research & Information paper modeling UK terraced homes during 2022 heatwave conditions estimated annual cooling electricity savings of 180-310 kWh per room when switching from single- to dual-hose, with payback under eight weeks at current tariffs. This directly addresses the editorial brief of a low-cost, months-scale intervention.

No jurisdiction yet mandates disclosure of infiltration losses on portable AC labels. Mandating the DOE-style pressure-neutral test or requiring dual-hose designs would shift the market faster than voluntary consumer education.