A fixed split, without hesitation. Portable air conditioners have a nominal SEER of 2.5 to 3, compared with 6 to 11 for a modern wall-mounted split. For the same floor area, a portable unit consumes 2 to 4 times more electricity. Its structural weakness is sealing. The hot-air exhaust hose passes through a partly open window, creating continuous incoming outdoor (hot) air that divides the effective SEER by ~2 compared with the nominal SEER shown on the product sheet. In actual use, a portable unit therefore operates at a SEER of around 1.3-1.5. It remains a supplementary solution for an occasional room, never a long-term office strategy.
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