BTU Sizing Guide: Matching AC Capacity to West African Rooms

2026-08-15

Start with room size

As a working rule for West African conditions: 9,000 BTU covers about 12–18 m², 12,000 BTU about 17–25 m², 18,000 BTU about 25–35 m², and 24,000 BTU about 35–45 m². Larger open spaces — shops, churches, restaurants — usually need 36,000 BTU and above, or several units zoned across the space.

Adjust for climate and building

Add 20–30% capacity for top-floor rooms under a hot roof, large west-facing glass, busy shops with door traffic, and humid coastal cities like Lagos, Accra or Cotonou where latent load is high. Kitchens and server rooms need their own allowance on top.

Undersizing vs oversizing

An undersized unit runs non-stop, wears out early and never quite cools — the most common complaint in the market. An oversized unit short-cycles: it cools the air fast but leaves humidity behind and stresses the compressor. Recommending the right size is the cheapest way to build a reputation for quality.