A refrigerant AC cannot — it must vent outside. If you have no window, use a ventless evaporative cooler (only in dry air) or vent through a wall/door.

Ventless needs no hose and installs anywhere but only cools well in dry climates (and adds humidity); window-vented refrigerant AC delivers real, strong cooling.

Dual-hose is more efficient — it pulls outside air for cooling instead of sucking conditioned air out. Single-hose is cheaper and fine for small rooms.

They blow cooler, moistened air, not true refrigeration; comfort comes from evaporation. In humid rooms they barely help.

Sliding and double-hung windows fit standard kits; casement/crank windows need an adapter panel. Seal any gap so warm air cannot leak back in.