If you are starting your research to buy an AC for your home needs, check out this guide on Best AC’s in India. This article will give further insights to what is becoming the most important factor in choosing ant electronic appliance, the ‘Star rating’.
The thumb rule for Tonnage
Before we get to the ‘Star rating’, let’s look at another major factor while choosing an Air Conditioner, the ‘tonnage’. The Bureau of Energy Efficiency (BEE) gives us the basic thumb rule for selecting appropriate sized AC for our needs.
0.75 Ton (AC capacity) – 75 to 100 sft (Room size)
1 Ton – 100 to 150 sft
1.5 Ton – 150 to 225 sft
2 Ton – 225 to 325 sft
3 Ton – 325 to 450 sft
3.5 Ton – 450 to 575 sft
You will find the salesperson pushing you to go for a higher Ton AC’s citing faster cooling. Although that’s correct (and mean more revenue to the sales company and higher power bill to you), you should stick to this guide for overall efficiency.
The Star rating effect
Now couple that thumb rule with the ‘Star rating’, you almost have the perfect energy saving AC for your room. The Star ratings start from 1 to 5, with 5 being the most energy efficient. Ask any sales person in any AC showroom regarding 5 stars rated AC’s, they will all say the same thing ‘go for the 5 star, if you use your AC for at least 10 hours a day’. While that is almost a correct statement, lets get more practical and see how much you can save ‘per year’, when you use a 1 star, 3 star and a 5 star AC under some fixed conditions.
Higher ratings Higher savings
For this purpose, I’m going to consider the most common household choice of AC (Split, that is) which is 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 city like Hyderabad.
For a 1 Star AC, the annual Electricity bill you will incur is about Rs.16341 (Rs.1361/month).
For a 3 stars AC, the annual Electricity bill could be Rs.14002 (Rs.1166/month).
For a 5 stars AC, the annual Electricity bill could be Rs.12249 (Rs.1020/month).
For most of the household, those bills per month could be quite burdensome, but the thing to look here is the difference in savings between 1, 3 and 5 star rated AC’s.
The fixed things that I took (12 hours a day for 150 days a year) here is the maximum that it could get for most. Most of the AC’s these days are intelligent enough to lower their performance according to the room temperature which will further cut the bills.
Update: On popular request from the readers, we are adding the savings details for a 1 Ton AC too.
1 TON AC (for 12 hours a day and 150 days a year)
1 star rated AC can bill up to Rs.10894 per year (Rs.907/month)
3 stars rated AC can bill to Rs.9335 per year (Rs.777/month)
5 stars rated AC can bill up to Rs.8166 per year (Rs.680/month)