9,000–12,000 BTU air conditioners ranked by cost to run
The most popular home size. 9,000–12,000 BTU suits bedrooms, home offices and average living rooms — roughly 20–28 m² (215–300 sq ft). We rank every unit in this bracket by what it costs to run per hour.
- Suits room
- ~20–28 m²
- Power draw
- ~750–1,400 W
- Cost/hr (UK)
- ~£0.18–£0.34
- Cheapest type
- Mini-split
Typical ranges for 9,000–12,000 BTU at UK rates (£0.245/kWh) — see the live listings below for exact specs per model.
Guides for 9,000–12,000 btu air conditioners
9,000–12,000 BTU air conditioners: frequently asked questions
What room size does 9,000–12,000 BTU cool?
Roughly 20–28 m² (about 215–300 sq ft) — a typical bedroom, home office or average living room. As a rule of thumb, allow about 450 BTU per m² (20 BTU per sq ft), then add capacity for sunny rooms, high ceilings or extra heat sources.
How much does a 9,000–12,000 BTU air conditioner cost to run?
It depends on the type. A mini-split in this range draws around 750–1,000 W (about £0.18–£0.25/hr at the UK average), while a single-hose portable of the same capacity can draw 1,200–1,400 W (about £0.29–£0.34/hr). Sort the table by cost per hour to see the cheapest.
Is 9,000 or 12,000 BTU better?
Match BTU to the room: 9,000 BTU suits smaller bedrooms (~20 m²), 12,000 BTU larger rooms (~28 m²). Oversizing wastes money and cools unevenly; undersizing runs the unit flat out. Use our BTU calculator, then compare units here.
