Uses the same engine as the full calculator (occupants 2, one large window assumed).
| Cooling load | — |
Common 600 sq ft room dimensions: 20×30 ft, 24×25 ft, 15×40 ft. The load depends on area, not shape.
US (single room): at roughly 22 BTU per sq ft, 600 sq ft carries about 13,200 BTU/hr, which the DOE room air conditioner chart matches to a 14,000 BTU window unit or mini-split. The smallest residential central system is 18,000 BTU — installing one here would oversize the room by 1.4× and cause short-cycling.
| US climate zone | Cooling load | Room unit |
|---|---|---|
| Zone 1 — Hot (FL, S.TX, AZ desert) | 16,800 BTU/hr | 18,000 BTU |
| Zone 2 — Warm (Deep South, TX) | 15,000 BTU/hr | 15,000 BTU |
| Zone 3 — Moderate (TN, NC, MO) | 13,200 BTU/hr | 14,000 BTU |
| Zone 4 — Mild (Mid-Atlantic, PNW) | 12,000 BTU/hr | 12,000 BTU |
| Zone 5 — Cool (Upper Midwest, New England) | 10,800 BTU/hr | 12,000 BTU |
India (room by room): Indian homes are cooled one room at a time, so 600 sq ft is not one big unit — it is 3 splits — 1.5T + 1.5T + 1.5T, about 4.5 ton in total. A typical layout at this size breaks down as:
| Room | Approx. area | Split size |
|---|---|---|
| Hall / living | ~168 sq ft | 1.5 ton |
| Bedroom 1 | ~138 sq ft | 1.5 ton |
| Bedroom 2 | ~138 sq ft | 1.5 ton |
Only cool the rooms you use. Sizing every room at once is how Indian households end up with two unused units and a higher connected load than the sanctioned supply allows — check your meter's sanctioned load before adding the last unit.
Figures assume 8 ft ceilings (9.5 ft for India), average insulation and normal sun. Your real number can swing ±30% — run the full tonnage calculator with your actual room data.
0.75 ton 1 ton 1.5 ton 2 ton 2.5 ton 3 ton 3.5 ton 4 ton 5 ton
About 13,200 BTU/hr in a moderate US climate, which matches a 14,000 BTU window unit or mini-split.
No. The smallest residential central system is 18,000 BTU, which is 1.4× the load of a 600 sq ft room. It would short-cycle and leave the room cold and humid.
3 splits — 1.5T + 1.5T + 1.5T — about 4.5 ton in total, cooling room by room.
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How these figures are derived: BTU per square foot, honestly · refine for your exact room with the full tonnage calculator.