10 Best Wall Mounted Ductless AC Units 2025 in the United States

The PIONEER Diamante Series Ductless Mini-Split Air Conditioner offers a robust solution for both cooling and heating with its 12000 BTU/hour capacity. Its high energy efficiency is highlighted by a 19 SEER, making it an attractive option for those looking to save on energy costs. Additionally, the noise level is relatively low at 40 dB, which means it operates quietly, a significant plus for indoor comfort.

The included installation kit, which features a 16 ft. line set and other accessories, simplifies the installation process, although some users might still prefer professional installation for optimal performance. This unit is capable of servicing areas up to 450 square feet, making it suitable for small to medium-sized rooms or light commercial spaces. The remote control feature adds convenience, allowing users to adjust settings without having to interact directly with the unit.

However, its voltage requirement of 230V means it may not be compatible with all residential wiring setups without modification. Another consideration is the unit's weight of 81 pounds, which might necessitate additional support during mounting. Those seeking an efficient and relatively quiet ductless AC unit with ease of use and installation features will find the PIONEER Diamante Series a compelling choice.

The COSTWAY 9000BTU Mini Split Air Conditioner & Heater is a solid choice for cooling and heating rooms up to about 450 square feet. With a cooling capacity of 9000 BTU and a SEER rating of 17, it is energy efficient compared to many basic models, helping keep electricity bills lower. The inverter technology means the compressor runs more smoothly, which also improves energy use and reduces wear. This model offers five modes—including cooling, heating, dry, fan, and auto—plus multiple fan speeds, sleep mode, and eco mode, making it flexible for year-round comfort.

Noise-wise, it runs at around 53 decibels, which is noticeable but not overly loud; it might be slightly distracting in very quiet rooms but generally tolerable during normal use. The unit comes with useful extra features like a self-cleaning function, washable filters, and auto-defrost for the outdoor part, which helps with maintenance and prolongs the unit's life.

Installation must be handled by a licensed HVAC professional, which is common for ductless systems but adds to upfront costs and effort. The unit uses the modern R32 refrigerant, which is better for the environment than older types. The included remote control is easy to use, and the timer and quiet display enhance convenience. This makes the COSTWAY unit a reliable, energy-saving mini split AC that also provides heating with good control options and environmental benefits, although the noise level might be noticeable in very quiet settings.