Tougher federal energy standards for window air conditioners make newer models cheaper to run. Look for a unit with an Energy Star label and an energy-efficiency ratio (EER) of 10 or above.

An curved arrow pointing right. Each year, we keep hitting record-high temperatures around the world, which has sparked a new wave of air conditioner purchases. This may pose a serious threat.

With the sun intermittently peering through the clouds and rain, transforming our living spaces into veritable ovens, the thought of buying an air conditioner ... models with high EER ratings ...

These air conditioners are designed to provide ... This efficiency is measured by the Energy Efficiency Ratio (EER), which indicates how much cooling an AC unit provides per unit of electricity ...