Window air conditioners and portable a/c units have their respective advantages and disadvantages. For example, window units are generally more efficient because they're sealed tightly in a window ...

An air conditioner’s size—which is an indicator of its cooling capacity—is measured in British thermal units per hour (Btu/hr.) or in “tons.” One ton of cooling equals 12,000 Btu/hr.

In reality, it’s all about cooling capacity. In the context of air conditioners, “ton” doesn’t mean how heavy the unit is — it refers to the amount of heat the AC can remove from a room ...