Choose a mini split by the room's heating and cooling needs, then confirm the electrical requirements. Square footage helps start the conversation, but it cannot tell you which system to order on its own.
What 9K, 12K and 18K mean
Mini splits are labeled in thousands of BTU per hour: 12K means a nominal capacity of 12,000 BTU/hr. That label is a size category, not a promise to cover a particular number of square feet. Your installer should compare the model's heating and cooling performance with the loads in your space.
Prepare your room details
- Room dimensions and ceiling height. Note open doorways and which rooms need separate temperature control.
- Windows, sun and insulation. Include large windows, afternoon sun, drafty areas and any planned insulation improvements.
- Location and use. Share your ZIP code, whether you need heating as well as cooling, and how you use the room.
- Installation layout. Identify possible indoor and outdoor locations and the route between them.
Ask for a room-by-room heating and cooling load calculation, commonly called Manual J. ENERGY STAR's ductless buying guidance recommends this check before choosing a system. A square-foot rule or an automatic step up for a sunny room is not a substitute.
Why bigger is not better
An oversized system can cycle on and off too often and struggle with humidity control. A smaller system can also fall short. If two sizes look close, have your installer check the calculated load against the equipment's capacity range instead of automatically choosing the larger or smaller unit.
115V or 220V: confirm the exact model
Capacity does not determine voltage. For example, NG offers SAJA 12K systems in both 115V and 220V versions. Check the exact product's electrical specifications and linked documents with your installer or electrician before ordering. A 115V label does not mean you can assume an existing household outlet or circuit is suitable.
Confirm the supply voltage, circuit and breaker requirements, wiring and disconnect for that model. Professional installation and job-specific materials are separate from the equipment price; see how installation is arranged.
Compare matching systems
These are options to compare once your installer has confirmed the requirements, not sizing recommendations for an unmeasured room:
Need another capacity? Compare all single-zone systems. For several rooms, discuss separate single-zone systems, a matched multi-zone system or ducted equipment with your installer. Room layout and the calculated loads matter more than a fixed whole-house square-foot cutoff.
For help finding the NG model and documents that match your installer's requirements, contact NG Trade. You can also browse the full catalogue.
