Star rating is a technique adopted by BEE (Bureau of Energy Efficiency) India to calculate the energy efficiency of an electronic appliance like window ac or split air conditioners. Depending on their energy efficiency they are rated on a scale of 1 – 5. More the number of stars, better is the energy efficiency of an air conditioner.
AC Star rating Calculation
The energy efficiency of an AC depends on two factors: Cooling capacity (in BTU) and Power consumption (in Watts)
The cooling capacity of one ton AC should be 12000 BTU, 1.5 ton AC should be 18000 BTU. Some companies rate their air conditioners as 1 ton but actually their cooling capacity is less than 12000 BTU. SO the BEE has brought into force star rating system so that the manufacturers cannot misguide the consumers
You should go for 5 stars rated AC’s, if you use your AC for at least 10 hours a day’. Check below and see practically how much you can save ‘per year’, when you use a 1 star, 3 star and a 5 star AC under same conditions.
I have choosen a 1.5 TON AC that is used for a 150 – 225 sft sized room and lets just say that you use the AC for 12 hours a day for 150 days in a year in a hot and humid season
For a 1 Star AC, the annual Electricity bill you will incur is about Rs.16000 (Rs.1333/month).
For a 3 stars AC, the annual Electricity bill could be Rs.13000 (Rs.1083/month).
For a 5 stars AC, the annual Electricity bill could be Rs.12000 (Rs.1000/month).
So decide yourself which ac you should buy ? While it is important to choose an AC with higher star rating, it is equally important not to compromise on the cooling capacity..