On the Bureau of Energy Efficiency (BEE) star label, is a 5 star window air conditioner (AC) better than a 1 star split AC?
Yes, on the Ministry of Power release's July 2022 to December 2024 table. A 5 star window or unitary unit needs an Indian Seasonal Energy Efficiency Ratio (ISEER) of 3.5, above the 3.3 of a 1 star split unit. But 3.5 only equals a 2 star split unit, and a 5 star split sits at 5.0. Stars do not compare.
The two tables, July 2022 to December 2024
- Split: 1 star 3.3, 2 star 3.5, 3 star 3.8, 4 star 4.4, 5 star 5.0.
- Window or unitary: 1 star 2.7, 2 star 2.9, 3 star 3.1, 4 star 3.3, 5 star 3.5.
- The figure in each row is the ISEER.
What to take from it
- Same stars, different machines. At 1 star the split is 0.6 above the window; at 5 star it is 1.5 above (5.0 minus 3.5).
- A 5 star window unit (3.5) is better than a 1 star split (3.3) but equal to a 2 star split (3.5).
- The release says split units saw frequent and substantial revisions compared with window units, due to technological and size constraints.
How to compare in kilowatt hours (kWh)
Use the ISEER on each label, not the star count. Electricity for a season is the seasonal cooling load divided by ISEER, which is my reading of how the release defines the ratio. Two units with the same load and hours can then be compared directly.
Same room, seasonal cooling load 6,000 kWh, at the band minimums (example)
- 5 star window at 3.5: 6,000 / 3.5 = 1,714 kWh
- 1 star split at 3.3: 6,000 / 3.3 = 1,818 kWh
- 5 star split at 5.0: 6,000 / 5.0 = 1,200 kWh
- 5 star window against 5 star split: 1,714 minus 1,200 = 514 kWh more
- For the financial year (FY) 2025-26 grid, 0.675 kilograms of carbon dioxide (CO2) per kWh: 514 x 0.675 = 347 kilograms of CO2 more a season
The 6,000 kWh load is an example. Real use depends on hours, room and weather. The 3.5 and 5.0 are band minimums, and a real label can sit above its minimum.
What Senseible does here
Senseible reads fuel invoices and electricity bills into monthly records, so the kilowatt hours on your bills before and after a change sit in one place.
- Split AC star bands, July 2022 to 2024
- Office AC replacement: CO2 saved
- AC at 24 C: energy saved
- Free calculators
Last reviewed 2026-11-05. Both band tables are from the Press Information Bureau release of 10 May 2023 and run to 31 December 2024. The release does not give later tables. The kWh comparison is arithmetic on those figures.