Free tool
What size air conditioning do I need?
Enter your room to get the right size in kW and BTU, using the same factors our engineers check.
Free, written quotes
Call us, ask for a call back or send a two-minute video of the room.
Quote by video 0330 520 2935Quick guide
Typical sizes by room
| Floor area | Typical room | Unit size |
|---|---|---|
| Up to 15 m² | Small bedroom, study | 2.0–2.5 kW |
| 15–25 m² | Double bedroom, home office | 2.5–3.5 kW |
| 25–35 m² | Living room, kitchen-diner | 3.5–5.0 kW |
| 35–50 m² | Open-plan living, small office | 5.0–7.1 kW |
| 50 m²+ | Large open-plan, shop floor | 7.1 kW+ or several units |
Based on a 2.4 m ceiling and average sun. Loft rooms, conservatories, big glazing and rooms full of computers need more.
We confirm the size before quoting, from a video or a visit anywhere in Cambridge and Cambridgeshire.
FAQs
Sizing questions
What size air conditioner do I need for a bedroom?
Most bedrooms need 2.0 or 2.5 kW. A loft bedroom or one with big south-facing windows may need 3.5 kW.
Is it bad to oversize air conditioning?
Yes. It cycles on and off, dries the air less, costs more to buy and can be noisier.
What is the difference between kW and BTU?
1 kW is about 3,412 BTU per hour. UK installers quote kW; portable units often use BTU.