RV load is higher per sq ft
RVs and campers have thin walls, minimal insulation, and large window area relative to floor space. Calculators apply a higher BTU factor than a stick-built room of the same size.
A 200 sq ft living area in a travel trailer often calculates 7,000–9,000 BTU — buy 9,000 BTU minimum. Full-timing in Arizona or Florida commonly uses 12,000 BTU for 250+ sq ft.
Sizing by RV type
Roof AC replacement projects sometimes downsized incorrectly — mini-splits are more efficient but still need honest load math, not roof-unit BTU copied blindly.
- Class B van: 100–150 sq ft cooled — 9,000 BTU typical
- Travel trailer 25–30 ft: 150–250 sq ft — 9,000–12,000 BTU
- Fifth-wheel or skoolie 30–40 ft: 250–350 sq ft — 12,000 BTU common
- Slide-outs add area and leak points — include them in dimensions
Power and generator planning
9,000 BTU inverter mini-splits often draw 800–1,200W running on 110V. Startup surge matters for inverter generators. Shore power at 30A service is usually sufficient for one head.
Verify amperage on the label before boondocking — these are rough planning numbers, not electrical engineering sign-off.
RV sizing by interior length
Enter slide-out dimensions in the RV mini-split calculator. Thin walls mean you will land at the high end of BTU per sq ft ranges.
- 20–24 ft trailer: 120–180 sq ft living → 9,000 BTU typical
- 25–30 ft trailer: 180–250 sq ft → 9,000–12,000 BTU
- 32–40 ft fifth-wheel: 250–350 sq ft → 12,000 BTU common
- Class A/C motorhome: measure actual cooled sq ft, not vehicle length