All new room air conditioners are required to carry an EER, or Energy Efficiency Rating, which ranges from 8 to 11.5. The ranking is important for consumers because air conditioners with higher EERs yield the most savings in monthly electric bills.

The higher EER also helps the environment by reducing greenhouse emissions. Check the yellow Energy Guide label on new room air conditioners when you’re shopping. A rating of 10 or higher will produce the most in energy savings, though these models are likely to cost a little more.

Many of the energy-efficient features in room air conditioners also offer greater convenience and comfort and include:

Variable fan speeds. More speed settings give you greater control of air flow. The lower settings also help save money.

Digital temperature control. The ability to control temperature by degrees—instead of with simple HIGH or LOW settings as previous models had—allows for greater comfort as well as increased energy savings.

Why we like it: • 8,000 BTUs--great size for mid-sized rooms • Remote control • Energy Star rating

Programmable thermostat. Though it comes as a premium, you may want to pay a little more for an AC unit that lets you program desired settings for different times of the day and night.

Easy-to-access filters. Slide-out filters are easy to clean and remove dust and other allergens from the air. Regular maintenance will extend the service life of your air conditioner and keep it operating at full efficiency.

Sleep setting/energy-saving setting. The unit operates at a very low setting during nighttime hours, making the room more comfortable for sleeping and at the same time saving on energy costs.

Timer. Timers are a simpler and less costly alternative to programmable thermostats. Just set the time you want the AC to start or stop. Timers let you come home to a house that already is cool without continuously running the air conditioner while you’re away.