noun
room cooler; air conditioner
A loanword from English, used for a device that cools a room. In Japanese, エアコン is more common for air conditioning in general, while ルームクーラー specifically emphasizes a cooling-only unit.
夏はルームクーラーがないと眠れない。
In summer, I can't sleep without a room cooler.
このルームクーラーは冷房専用です。
This room cooler is for cooling only.