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Home cooling accounts for nearly 20 percent of household electricity consumption, so an energy-efficient air conditioner could be a real money saver. High-efficiency appliances typically cost more than the cheapest options, but payback comes in the form of smaller power bills every month. Those in warmer climates and areas with higher electricity rates realize those savings even faster.
Energy efficiency in window air conditioners starts with proper sizing: 15 to 20 BTUs per square foot of space. Deviating from that formula risks overworking the air conditioner in a space that is too big, or cooling the air before it is properly dehumidified if the appliance is too powerful. Next, check out units that feature inverter technology, display the Energy Star seal, and feature combined energy efficiency ratio (CEER) ratings of 12 or higher. We fell in love with the Windmill 8,000 BTU WhisperTech Window Air Conditioner, which is the right size for cooling rooms from 250 to 533 square feet. It’s easy to install, looks great, and boasts a CEER 15 rating.
Best Overall
Windmill 8,000 BTU WhisperTech Window Air Conditioner
Buy at The Home Depot Buy at Lowe's Buy at Staples
What We Like
- Energy Star certified
- Pre-assembled for installation
- Double-walled insulation
- Dual air intake filtration system
What We Don’t Like
- Fixed airflow angle
- More expensive than similar options
Product Specs
- CEFR: 15
- Dimensions: 13.2 inches by 19.3 inches by 23 inches
- Weight: 60 pounds
There’s more to an air conditioner than its energy efficiency rating, and the Windmill 8,000 BTU WhisperTech Air Conditioner has a lot to offer. It features a high-efficiency CEER 15 rating and low-noise operation, all made possible by state-of-the-art industry inverter technology. Plus, it has a sleek, modern appearance complemented by convenient smart controls.
The Windmill window air conditioning unit exploded in popularity thanks in part to its unconventional appearance that looks great from inside or outside the home. The mesh vent cover gives it a clean-lined look, more like a built-in speaker than an AC window unit. It draws less visual attention than other air conditioner designs, but its 45-degree upward-facing supply vent cools rooms quickly and thoroughly.
We also like that this unit is WiFi-ready, allowing for remote control via iOS or Android mobile app, or voice control with Google Assistant or Amazon Alexa. Choose from three cooling modes (normal, eco, or fan) and three fan settings. As for installation, it could not be much easier. The installation kit is factory assembled in the box, with crystal clear instructions for quick setup in single-hung or double-hung windows.
Get the Windmill energy-efficient air conditioner at Home Depot, Lowe’s, Staples, or Best Buy.
More Energy-Efficient Air Conditioners Worth Your Money
Our top pick may not suit every reader’s needs, so we’ve listed more great options below. All of these air conditioning units include high-efficiency CEER 15 ratings. Most of them also come with smart technology for improved operating convenience.
- Whirlpool 8,000 BTU Inverter Window Air Conditioner, available at Tractor Supply Co., The Home Depot, Best Buy, or Sylvane.
- Frigidaire Gallery 12,000 BTU Window Air Conditioner, available at The Home Depot, Wayfair, or Frigidaire.
- LG 12,000 BTU Dual Inverter Smart Window Air Conditioner, available at Lowe’s, Best Buy, or LG.
- GE Profile 14,000 BTU Inverter Smart Window Air Conditioner, available at Amazon, Lowe’s, GE, or Plesser’s.
How We Chose the Best Energy-Efficient Air Conditioners
Technology constantly changes and improves, so it is important to update efficiency standards from time to time. Before choosing products for this guide, we reviewed the most recent United States Department of Energy room air conditioner criteria for Energy Star certification. We determined that CEER 15-rated models would qualify as “best” with regard to energy efficiency. We shopped for established brands with outstanding track records for quality and customer service. Since 8,000 BTU is the most popular window air conditioner size, our top recommendation would fall into that size range. We also wanted to include other available sizes, popular features, and designs to showcase the variety of energy-efficient options that are available. After vetting more than 30 air conditioners, we narrowed our list to the 5 in this guide.
FAQs
Understanding how to maintain and operate an air conditioner to get the most out of it is key to ensuring home energy efficiency during the summer months. Ahead, learn about the most efficient way to run a window air conditioner and learn how upgrading your aging AC unit to a newer model can save you money.
A new air conditioner generally uses less electricity because it is more technologically advanced than older models. Air conditioner compressors also cool less efficiently as they get older, forcing them to work harder and use more energy to cool the room.
There are several ways to reduce the power consumption of an air conditioner. The most obvious is turning up the thermostat to a higher temperature. Clean the air conditioner and replace the filter regularly to ensure the air conditioner is in peak condition. If possible, switch to a smart thermostat that allows you to schedule on/off times for the air conditioner so it isn’t running when it doesn’t have to.
It is cheaper to leave the air conditioner on all day if it’s hot outside. Turning off the air conditioner during hot and humid weather can allow heat and humidity to quickly build up in the home. Re-cooling the home places excessive strain on the air conditioner. A better option is to adjust the air conditioner by a few degrees when you’re not home.
Fans are much cheaper to operate than air conditioning systems because they do not use a compressor. It’s a good idea to use fans in combination with a room air conditioner to make the air feel cooler, allowing you to increase the thermostat a few degrees.
A 20-year-old air conditioner is much less efficient than today’s models. An older air conditioner may use 6 kilowatt-hours of electricity to cool an average house, while a modern power power-efficient air conditioner system can use less than 2 kilowatt-hours to cool the same space.
Mini-split air conditioners or wall air conditioning units are much more efficient than window units. The average mini-split wall mount air conditioner consumes 40 percent less energy than a window air conditioner to cool the same space.
Air conditioner types depend on what you’re trying to cool. If your goal is single room air condition, then a window unit air conditioner is the best option. If you need to cool an entire home, it’s more economical to use a central air conditioner than to place a window unit in every room of the home.
