10 Best Energy Efficient Window Air Conditioners 2025 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 GE Profile PHNT12CC Clearview Air Conditioner is a strong choice for medium-sized rooms up to about 550 square feet. Its 12,200 BTU cooling capacity is suitable for this space, offering efficient cooling without overworking the unit. It stands out with inverter technology, which adjusts cooling power smoothly to save energy—this helps it achieve a solid Seasonal Energy Efficiency Ratio (SEER) of 12.1, meaning lower electricity costs compared to less advanced units. Noise is kept low at around 40 decibels, making it one of the quietest window ACs available, so it won't disturb your daily activities or sleep. The unique full-window view design is a nice touch, preserving natural light and letting you open and close your window normally after installation.

Installation is also flexible thanks to the adjustable depth feature, accommodating different window sill thicknesses for a secure fit. On the smart features side, the built-in WiFi and compatibility with Alexa and Google Assistant make controlling the unit from your phone or voice commands convenient. It also includes a filter light reminder to help you maintain air quality easily.

The main drawbacks include its weight—about 76 pounds—which might make installation tricky without help. The warranty is fairly standard at one year, which is on the shorter side for a premium product. Some users might find the price a bit higher than basic models. This AC is ideal for those seeking a quiet, energy-efficient, and smart-controlled window unit for medium rooms and who are willing to invest a bit more upfront for these benefits.

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.