10 Best Energy Efficient Window Air Conditioner 2025 in the United States

The Midea 12,000 BTU Smart Inverter Window Air Conditioner is a solid choice for anyone needing to cool or heat a medium to large room up to 550 square feet. Its inverter technology and Energy Star rating mean it uses electricity efficiently, potentially saving you up to 35% on energy costs compared to less efficient models. With a Seasonal Energy Efficiency Ratio (SEER) of 13.3, it performs well in cooling without running up your electric bill. This unit is also versatile since it offers heating and dehumidifying modes, making it useful beyond just summer.

One of the standout features is its quiet operation, running as low as 45 dB, which is ideal if you want a peaceful room for work or sleep. It includes multiple fan speeds, a 24-hour programmable timer, and can be controlled via a remote, an app, or even voice commands with Amazon Alexa or Google Assistant, adding convenience. The washable front filter is easy to access, helping maintain good air quality and unit efficiency.

Keep in mind that the heating function won’t work if outdoor temperatures drop below 41°F, so it’s not designed for very cold climates. Also, the noise level is noted as 58 dB in specs but described as 45 dB in marketing—expect quiet operation, but actual noise may vary depending on settings. Installation requires a double-hung window with specific dimensions, so make sure your window fits. This AC unit suits those who want a combination of cooling, heating, and energy efficiency with smart features, but it may be less ideal for strong heating needs in freezing conditions or incompatible window sizes.

The Amazon Basics 5000 BTU window air conditioner is a compact and affordable option designed for small rooms up to 150 square feet, such as bedrooms or home offices. It offers decent cooling power for its size and includes both cooling and fan-only modes, providing flexibility depending on your needs. The unit operates quietly at up to 56 dB, making it suitable for sleeping or working without much disturbance. It comes with a washable pre-filter that helps capture dust and allergens, which is easy to maintain and a plus for cleaner air. The air conditioner features 7 temperature settings and 2 fan speeds, allowing some customization, along with adjustable airflow direction.

Installation is straightforward with adjustable side panels to fit most standard windows, although basic tools and some effort are required. The product has an Energy Efficiency Ratio that supports reasonable energy use, but it lacks a programmable timer and remote control, which might limit convenience for some users. The mechanical controls are intuitive but less advanced compared to digital or smart models. This air conditioner suits those who want simple, reliable cooling for a small space and prefer easy maintenance, but it might not be ideal if you want advanced features like remote operation or precise scheduling.

The Amazon Basics Window Air Conditioner with 6000 BTU is a solid choice for cooling and dehumidifying rooms up to 250 square feet. For those seeking an energy-efficient solution, this unit stands out with a CEER of 12.1, which ensures cost-effective operation.

It comes equipped with convenient controls, including a remote, a 24-hour programmable timer, auto restart, and sleep mode, allowing you to customize your cooling experience easily. The built-in filter is both removable and washable, making maintenance easy and keeping the air clean.

Installation is designed to be straightforward, with adjustable side panels to fit standard windows, adding to its versatility. However, at 41.89 pounds, it may be a bit heavy for some users to install alone. The 6000 BTU cooling power is adequate for small to medium rooms, but those with larger spaces may need a unit with higher BTU.