Best air conditioners by size
98 shortlists cover the standard UK sizes, and the quietest 3.5 kW (12,000 BTU) list has 981 models. If the room is a different size, use that row; a registration under 1.0 kW is left out.
computed
Size by what you are optimising
13 standard sizes have at least one list. Each number is the model count.
| Size | Quietest | 37 dB at 3 m | 37 dB at 4 m | R290 | R32 | SEER | SCOP | £ / summer | 2 rooms | Price |
|---|---|---|---|---|---|---|---|---|---|---|
| 1.5 kW (≈5,000 BTU) | 13 | — | — | — | 11 | 13 | 9 | 13 | 4 | — |
| 2 kW (7,000 BTU) | 130 | — | 21 | — | 105 | 131 | 129 | 131 | 6 | 9 |
| 2.5 kW (9,000 BTU) | 750 | 8 | 36 | 10 | 652 | 753 | 750 | 753 | 17 | 9 |
| 3.5 kW (12,000 BTU) | 981 | — | 15 | 13 | 840 | 984 | 974 | 984 | 41 | 5 |
| 4.2 kW (14,000 BTU) | 418 | — | — | — | 378 | 419 | 419 | 419 | 123 | — |
| 5 kW (18,000 BTU) | 1322 | — | 11 | — | 1170 | 1324 | 1321 | 1324 | 255 | 5 |
| 6 kW (21,000 BTU) | 457 | — | — | — | 391 | 458 | 458 | 458 | 86 | — |
| 7.1 kW (24,000 BTU) | 1523 | — | — | — | 1176 | 1523 | 1523 | 1523 | 181 | — |
| 8 kW (≈27,000 BTU) | 679 | — | — | — | 536 | 679 | 679 | 679 | 150 | — |
| 10 kW (≈34,000 BTU) | 1637 | — | — | — | 1147 | 1638 | 1636 | 1638 | 300 | — |
| 12.5 kW (≈43,000 BTU) | 252 | — | — | — | 63 | 253 | 253 | 253 | — | — |
| 14 kW (≈48,000 BTU) | 39 | — | — | — | 39 | 39 | 39 | 39 | — | — |
| 16 kW (≈55,000 BTU) | 22 | — | — | — | 22 | 23 | 23 | 23 | — | — |
Lists with no size cut
4 lists cover every family at 1.0 kW and above.
| List | Models |
|---|---|
| Quietest split air conditioners in the UK | 6686 |
| R290 air conditioners in the UK | 355 |
| Highest-SEER air conditioners in the UK | 8275 |
| Cheapest air conditioners to run in the UK | 8275 |
EPREL manufacturer-declared registrations and the shop snapshot · snapshot 25 Sep 2026 · n=98 · Families map to the nearest standard size when the gap is within 15%. · updated 25 Sep 2026 · version 1.0.0 · CSV of the values on this page
How this page was calculated
Families map to the nearest standard size when the gap is within 15%.
Better than a bare directory: the first sentence is a number you can check on the linked page.