Refers to a machine or device that cools the air, typically an air conditioning unit. Not used for a simple fan.
夏は冷房機がないと眠れない。
In summer, I can't sleep without an air conditioner.
この部屋の冷房機は古くて効きが悪い。
The air conditioner in this room is old and doesn't work well.
Standard kanji spelling for an air conditioning unit.
Alternate kanji spelling; 器 is a general character for devices, but 冷房機 is more common.
Compound of 冷房 (cooling, air conditioning) and 機 (machine, device).