10 Best Energy Efficient Window Air Conditioners 2026 in the United States

The Midea 12,000 BTU Smart Inverter Air Conditioner is a solid choice if you need to cool or heat a room up to about 550 square feet. It offers multi-season comfort by providing both cooling and supplemental heat, though the heat feature won’t work when it’s very cold outside (below 41°F). It stands out for its energy efficiency with an Energy Star rating and inverter technology that can save up to 35% on electricity compared to standard models, which helps lower your energy bills. The unit is fairly quiet at around 45 to 58 dB, meaning it won’t be too disruptive whether you’re working, watching TV, or sleeping.

You’ll find it easy to operate thanks to its electronic controls, remote control, and smart features that let you adjust settings from an app or with voice commands via Alexa or Google Assistant. The 24-hour timer and multiple modes (heat, cool, dry, fan) add flexibility for different needs. Maintenance is straightforward with a washable front panel filter, helping keep the air clean and the unit running efficiently. Installation fits standard double-hung windows between 24 and 38.5 inches wide, and the unit’s size is typical for this power level.

A potential drawback is that the noise level can reach up to 58 dB on higher settings, which might be noticeable in very quiet spaces. The heat function has limitations in colder climates, and the unit weighs 58 pounds, so installation may require some effort. Priced competitively, the advanced features and energy savings make this unit an excellent option for those seeking reliable, year-round climate control with smart convenience.

The Midea MAW12V1QWT U-Shaped Window Air Conditioner stands out for its energy-saving capabilities, boasting over 35% savings thanks to advanced DC inverter technology and a strong 5-star energy rating. With a cooling capacity of 12,000 BTUs, it effectively cools rooms up to about 550 square feet, making it a solid choice for medium-sized spaces. One of its most notable features is the ultra-quiet operation at just 32 decibels, which is much quieter than typical window ACs, ensuring minimal noise disturbance.

The unique U-shaped design is clever, as it allows you to keep your window partially open for fresh air and a better view, while also including an anti-theft lock for safety. Smart controls are another plus, allowing remote adjustments through a phone app or voice assistants like Alexa and Google Assistant, adding convenience for modern users. Installation is straightforward with a quick-snap bracket, suitable for most single or double-hung windows between 22 and 36 inches wide. The unit includes a dust filter with a clean filter indicator to help maintain air quality.

While the unit is efficient and packed with features, it weighs nearly 59 pounds, which might be a bit heavy for some users to handle during installation. Also, the warranty is limited to two years, shorter than some competitors offer. This Midea model is well suited for those wanting an energy-efficient, quiet, and smart window AC with easy installation and a fresh-air friendly design.

The LG 18,000 BTU Heat and Cool Window Air Conditioner is designed for medium to large rooms up to 1,000 sq. ft., offering strong cooling and heating capabilities with a decent 11.1 SEER rating, which means it's reasonably energy efficient for its size. The 18,000 BTU power is quite effective in managing room temperature, whether you want to cool or add warmth during cooler days, thanks to its supplemental heat feature. With a noise level of 57 dB, it’s moderately quiet—not whisper silent but should be acceptable for most living spaces.

One of its standout features is smart control via LG ThinQ technology, allowing you to adjust settings remotely with your phone or voice commands through Alexa and Google Assistant, which adds convenience for everyday use. It also includes practical touches like a 24-hour timer, auto-restart after power outages, and a filter light reminder that helps keep maintenance straightforward. Installation fits standard windows, and the included kit makes setup easier. However, it’s a relatively heavy unit at about 126.5 pounds, which could make installation tricky if you’re doing it alone.

This LG model is suitable for those who want a powerful, versatile air conditioner with smart features for easy control, especially in larger rooms, while being prepared for a moderate noise level and a heavier installation.