10 Best Thru Wall Ac Units 2026 in the United States

The Keystone 18,800 BTU Window-Wall Air Conditioner is a versatile unit that combines cooling, supplemental heating, dehumidification, and fan circulation, making it suitable for large rooms up to 1,000 square feet. With a cooling capacity of 18,800 BTUs and a supplemental heating capacity of 16,000 BTUs, it can provide comfort year-round. The unit includes a smart remote with an LCD screen that helps maintain the desired room temperature by sending signals to the air conditioner every three minutes. It offers energy-saving modes like 'Energy Saver' and 'Sleep' to help reduce electricity bills, although its SEER rating of 10.7 is relatively average, and it is not Energy Star certified.

The noise level is 55 dB, which is moderate and may not be the quietest option available but should be manageable for most users. Installation is straightforward with the included window installation kit, and the space-saving design helps free up floor space. Additional features include a filter light reminder and a 4-way swing for better air distribution. However, it weighs 117.3 pounds, making it quite heavy and potentially challenging to install without assistance.

While it performs well in cooling and supplemental heating, it’s important to note that the heating function is not meant to replace a primary heat source, especially in extremely cold conditions. The product comes with a 1-year parts and labor warranty and an additional 4-year warranty for the sealed system, providing some peace of mind regarding durability.

The Keystone 12,000 BTU through-wall air conditioner is designed to cool medium-sized spaces up to 550 square feet, making it suitable for bedrooms, nurseries, or bathrooms. With a solid cooling capacity of 12,000 BTUs, it efficiently manages temperature and includes a built-in dehumidifier that removes about 2.3 pints of moisture per hour, helping improve comfort on humid days. In terms of energy use, it has an Energy Efficiency Ratio (EER) of 10.5, supported by energy-saving modes like 'Energy Saver' and 'Sleep' that help reduce electricity bills without compromising comfort.

The noise level sits at around 56.5 decibels, which is average for this type of unit—noticeable but not overly loud for most rooms. Installation requires mounting through a wall, which keeps your window space free and maintains a clean look inside, though some effort is needed to fit it properly using the included trim kit. The unit also comes with a smart remote control that measures the room temperature and adjusts settings accordingly every few minutes, making it easy to use.

Additional helpful features include adjustable airflow louvers, programmable timer, and a filter light reminder to keep maintenance on track. The unit’s weight at over 78 pounds means installation may require assistance. Though it doesn’t have a star energy rating, its combination of features and reasonable energy efficiency make it a solid choice for those seeking a reliable, quiet, and space-saving air conditioner for moderately sized rooms.

The COSTWAY 12000BTU Mini Split Air Conditioner & Heater is a versatile unit designed for both cooling and heating spaces up to 750 square feet. With a high Seasonal Energy Efficiency Ratio (SEER) of 20.0, it promises excellent energy efficiency, which can lead to lower utility bills. The unit operates relatively quietly at 51 dB, which is generally considered acceptable for residential use, ensuring it won't disrupt your peace and quiet significantly.

The included remote control and multiple modes (auto, cool, dry, heat, and fan) provide flexibility and convenience for year-round comfort. The self-cleaning feature at high temperatures and auto-defrost function contribute to maintaining air quality and system longevity. However, installation must be done by a licensed HVAC installer, which could add to the initial cost and complexity. Additionally, the product uses R32 refrigerant, which is more environmentally friendly but might require specific inquiries about its availability for future maintenance.

With a robust warranty covering parts for 5 years and the compressor for 8 years, this unit offers long-term reliability. Potential buyers should consider the installation requirements and ensure compatibility with their existing setup. This unit is ideal for those looking for an energy-efficient, multi-functional air conditioning solution for medium-sized rooms.