Best Mini Split Air Conditioners (2026)

This Rellytech is a conventional inverter heat pump: the outdoor compressor varies its speed to hold the setpoint instead of cycling on and off, which is where the efficiency rating and the steady room temperature come from. It lists 12,000 BTU of cooling and 12,500 BTU of heating, so it does not lose capacity when you flip it to heat, and it runs on 115V, which keeps the electrical work simple.

The tradeoff is that it is still a split system. Someone has to mount the indoor head, drill a three-inch class wall penetration, run the line set and make the refrigerant connections. Next to the 9,000 BTU Rellytech or the ROVSUN it covers a noticeably larger room, but its higher rating buys you nothing if the room is a small bedroom. Match it to a living room or open studio.

Ownership is routine. The indoor filter needs a rinse every month or two in a dusty house, the condensate drain must stay sloped, and the outdoor coil needs clearing of leaves and cottonwood. Parts for these value-brand units come from the same few factories, so expect to buy the remote or a circuit board from the seller instead of a local supply house.

Albott builds this unit around an inverter heat pump with an 18 SEER2 rating, and the listing states heating operation down to 5F outdoors. That is the number to care about if the system will be your winter heat source, because plain heat pumps lose output quickly as the outdoor temperature drops and cheaper ones simply stop heating.

It gives up a little on paper efficiency to the Rellytech 12,000 BTU at 19 SEER2, a one-point gap that will not show up on your electric bill. What it offers instead is a low-temperature rating and the usual four modes. Treat the 5F figure as a lower operating limit, not a promise of full capacity, and plan on a supplemental heat source if your design temperature is near zero.

Outdoors, the main job is keeping the unit elevated above snow line on a wall bracket or pad and keeping the defrost drain from freezing into an ice mound. Indoors, the filter and condensate line are the same chores as any head. If you are shopping for the same capacity in a cold region, this is the one I would start with.

The ROVSUN 9,000 BTU is the sensible size for a bedroom, home office or small addition, and it lists 20 SEER2 efficiency, the highest rating among the 9,000 and 12,000 BTU units that I am comparing apart from the Temprium 22 SEER2 model. Its 28 dB figure applies to mute mode, which runs the fan at its lowest speed, so you should expect more sound whenever the compressor is working hard.

Its limits are capacity and support. At 9,000 BTU it has about three-quarters of the cooling capacity of the 12,000 BTU Rellytech, which is the correct answer for roughly a 350 to 450 square foot room but a poor one for an open plan. Wi-Fi control is convenient, but the app is the part most likely to age out, so make sure you are happy with the physical remote.

Installation and upkeep match the other single-zone systems here. The indoor head wants a monthly filter rinse in summer, and the outdoor unit needs a level pad and clear airflow on all sides. It is the cheapest way into a true heat pump in this lineup, so the question is only whether 9,000 BTU is enough for your room.

Temprium's 12,000 BTU system carries the highest efficiency rating of the group at 22 SEER2, ahead of the 19 SEER2 Rellytech of the same capacity and the 18 SEER2 Albott. A higher SEER2 comes from a more tightly controlled inverter compressor and a larger coil, so in a room that runs the system for many months the savings are real, though the gap against 19 SEER2 is modest.

The 23 dB claim is the lowest sound figure in the lineup, but it is measured at the lowest fan speed, and indoor head noise rises quickly as you move up the fan steps. Coverage is listed up to 750 square feet, which is generous for 12,000 BTU, and I would treat it as a mild-climate, well-insulated figure.

On the ownership side this is a newer brand, so lean on the written warranty terms more than on forum history. Keep the indoor coil clean, keep the drain line sloped and clear, and keep the invoice, because warranty claims on split systems often require proof of correct installation.

This is the same Rellytech platform scaled up to 18,000 BTU of cooling and 18,400 BTU of heating. The step up demands 208 to 230V, which means a dedicated two-pole breaker and the proper wire gauge, so factor an electrician into the project. In exchange, you get half again the capacity of the 12,000 BTU model, enough for a large living room or a basement with a lot of glass.

Capacity is the point, but so is restraint. If the room is only 700 square feet of well-insulated space, this will cycle on low and be less efficient than a correctly sized 12,000 BTU system. It makes the most sense for a big open area or a poorly insulated garage conversion.

The outdoor unit is heavier and wants a proper pad or heavy-duty wall bracket. The care is identical to the smaller units: monthly filters in season, a sloped drain, and a clear coil. Compared with the Temprium 24,000 BTU model it uses a smaller compressor, which saves a little on wiring size.

At 24,000 BTU this is a two-ton system, listed for up to 1,500 square feet. That is the capacity to look at for an open ground floor, a big shop or a long great room where one head must throw air a long distance. It uses 230V and a larger line set, so the project cost climbs along with the capacity.

A single indoor head on one wall still limits what it can do. In a house with closed doors and several rooms the far bedrooms will stay warm, so I would only buy this size for a space that is truly open. Against the 18,000 BTU Rellytech it adds one third more capacity, and against the 12,000 BTU Temprium it doubles it.

Expect a heavy outdoor unit and a meaningful installation job. Plan the pad, a service disconnect, and drain routing before you order, and keep a record of the line set length, since the charge is set for a standard run.