What BTU for which area? Portable air conditioner calculation guide

Which BTU to Choose for Which Area?

Quick calculation of the ideal BTU based on your room, with concrete examples for apartments, houses, and offices in France.

Answer in One Sentence

Multiply the area of your room (in m²) by 400 to get the required BTU. Example: 23 m² × 400 = 9,200 BTU → choose 9,000 BTU.

Quick Reference Table

Area Recommended BTU Coldest Breeze Model Typical Use
10 m² 4,000 BTU Mini Silent Air Conditioner (€49) Small office, child's bedroom
15 m² 6,000 BTU Mini or USB (depending on use) Adult bedroom, studio
20 m² 8,000 BTU Coldest Breeze™ Lite Standard bedroom
23 m² 9,000 BTU Coldest Breeze™ Pro Medium room, living room
25 m² 10,000 BTU Ultra Standing Air Conditioner Large living room
30 m² 12,000 BTU Coldest Breeze™ Max Open space, family living room

Factors That Increase Required BTU

  • High ceiling (>2.5 m): +10% BTU
  • South-facing exposure: +15% BTU
  • More than 2 people in the room: +600 BTU per additional person
  • Kitchen room: +4,000 BTU (heat from appliances)
  • Lots of electronic equipment: +1,000 BTU (TV, PC, console)

Concrete Examples

Case 1: Adult Bedroom 16 m² in Attic

16 m² × 400 = 6,400 BTU + 10% (low ceiling but south-facing) = 7,040 BTU → ideal 9,000 BTU model (comfort margin).

Case 2: Living Room 28 m² with Open Kitchen

28 m² × 400 = 11,200 BTU + 4,000 BTU (kitchen) = 15,200 BTU → minimum 12,000 BTU model, ideally two air conditioners.

Case 3: Home Office 12 m² with PC + 2 Screens

12 m² × 400 = 4,800 BTU + 1,000 BTU (electronics) = 5,800 BTU → 6,000 BTU model or mini USB air conditioner.

Common Mistake: Undersizing

An undersized air conditioner runs constantly without reaching the desired temperature: high consumption, constant noise, premature wear. Better to have a 10% BTU margin than exactly on target.

What About Oversizing?

Too powerful = short on/off cycles = poor humidity control and peak consumption. Stay within the recommended range + 10%.

See Our Models by BTU

Free Delivery in France + 2-Year Warranty

All Coldest Breeze portable air conditioners are delivered free in France within 4 to 7 business days, with free 14-day returns and a 2-year warranty against manufacturing defects.