3 Best Keystone Air Conditioners 2025 in the United States

The Keystone 14,000 BTU Wall Mounted Air Conditioner is well-suited for large rooms up to 700 square feet. Its cooling capacity ensures effective temperature regulation during hot months, while the 10,600 BTU supplemental heating capacity provides some warmth when it's cooler outside, though it's not intended to replace primary heating systems. The dehumidifier function adds to its versatility, making it a useful year-round appliance.

However, it requires a specific 230V/20-amp outlet, which might be a limitation for some users. The unit operates relatively quietly at 61.5 dB, which is manageable but not the quietest on the market. The included remote control enhances convenience by measuring room temperature and adjusting settings accordingly. Energy-efficient modes like 'Energy Saver' and 'Sleep' can help reduce electricity costs, though it's worth noting that the unit does not have an Energy Star rating.

The Seasonal Energy Efficiency Ratio (SEER) of 9.3 indicates moderate efficiency but may not be the most cost-effective over time compared to higher-rated units. The unit's bright white color and compact, wall-mounted design allow it to blend into most living spaces without obstructing window views or taking up floor space. It also comes with a 1-year parts and labor warranty, plus an additional 4 years for the sealed system, providing some peace of mind. Potential buyers should weigh the need for a special electrical outlet and the moderate energy efficiency against its robust cooling and supplemental heating capabilities.

The Keystone 12,000 BTU Window-Wall Air Conditioner is a solid choice for cooling medium-sized rooms up to 550 square feet, making it suitable for living rooms or apartments. With a strong cooling capacity of 12,000 BTU and an added 11,000 BTU supplemental heating feature, it offers flexible year-round comfort, though the heating mode is meant only as a backup, not a primary heat source. Its energy efficiency rating (SEER) of 10.9 is decent, helping manage electricity costs especially when using energy-saving modes like 'Sleep' or 'Energy Saver.' Noise level is around 55 decibels, which is average for window units—not completely silent but unlikely to be too disruptive for most users.

The unit includes helpful extras like a smart remote that reads and adjusts the room temperature automatically, a dehumidifier, and a 4-way swing feature for better air distribution. Installation is straightforward with the included window kit, and the design saves floor space since it fits in a window or wall opening. On the downside, it weighs about 72 pounds, which may require some effort to install, and the heating function is limited to moderate outdoor temperatures. Also, the 1-year warranty with an extra 4 years on the sealed system offers some peace of mind.

If you need a versatile unit that can handle cooling and occasional heating efficiently in medium rooms without breaking your budget, this Keystone model is a worthy option.

The Keystone 8,000 BTU Slider Window Air Conditioner is a solid choice for cooling bedrooms or living rooms up to 350 square feet. Its 8,000 BTU capacity is well suited for small to medium-sized rooms, providing effective cooling without being overpowered. The unit includes a built-in dehumidifier that removes 0.9 liters of moisture per hour, which helps improve comfort in humid conditions. With a Seasonal Energy Efficiency Ratio (SEER) of 10.8, it offers decent energy efficiency, and features like 'Energy Saver' and 'Sleep' modes help reduce electricity costs. Noise-wise, it operates at about 57 decibels, which is moderate—noticeable but generally not disruptive during normal use.

Installation is flexible thanks to the removable chassis and adjustable window kit, fitting standard sliding or casement windows. The 4-way air direction control and multiple fan speeds allow you to tailor airflow where you need it most. On the downside, the noise level might be noticeable in very quiet rooms, and the cooling power limits it to smaller areas, so it’s not ideal for larger spaces.

The 1-year warranty provides basic coverage, but some users might want longer protection. If you need a budget-friendly, easy-to-install window unit for a smaller room that also tackles humidity, this Keystone model is a practical option.