Most of us have heard about star ratings for home appliances. We have read about it on the web, and even heard people talking about higher star rating being better. Terms such as EER and ISEER are used especially for air conditioners and refrigerators but what do they mean?
In comparison, using star ratings is one of the easiest ways to determine and compare energy efficiency of home appliances. We shed some light on the different aspects of EER, ISEER, star rating standards and tell you why they are so important when you are buying an air conditioner.
What is EER? Why is it called ISEER?
The Bureau of Energy Efficiency (BEE) has a grading system called Energy Efficiency Ratio (EER). This is meant for home appliances such as air conditioners, refrigerators and other electrical equipment. Air conditioners are rated in BTU (short for British Thermal Unit) regardless of their capacities and tonnage. This BTU number tells you how fast an air conditioner can cool a room, with a fixed temperature outside.
Since the temperatures across India vary and see extreme changes through the seasons, the EER standards method of calculating performance were less than ideal. Air conditioners consume a lot of energy, resulting in high electricity bills. Thus, BEE defined a new seasonal EER rating standard called ISEER in India.
BEE – What the label means?
There aren’t any major changes to the BEE power savings label, except the word ISEER on it. This new label has star ratings listed on the top and other details such as the star ratings, annual electricity consumption units, manufacturer unique identification number, product details and a BEE logo below.
How is ISEER different?
The ISEER (Indian Seasonal Energy Efficient Ratio) rating standard was made mandatory from 2018. On the newly introduced ISEER rating standard, the existing EER star ratings brackets were revised. Also, keep in mind that ratings are different for Window and Split air conditioners. Given below are BEE defined, ISEER ratings valid from 1st January 2018 to 31st December 2019.
ISEER ratings for Window ACs(Fixed and Variable speed ) |
ISEER ratings for Split ACs(Fixed and Variable speed ) |
|||||
Star level |
Minimum |
Maximum |
Star level |
Minimum |
Maximum |
|
|
1 Star |
2.50 |
2.69 |
1 Star |
3.10 |
3.29 |
|
|
2 Star |
2.70 |
3.89 |
2 Star |
3.30 |
3.49 |
|
|
3 Star |
2.90 |
3.09 |
3 Star |
3.50 |
3.99 |
|
|
4 Star |
3.10 |
3.29 |
4 Star |
4.00 |
4.49 |
|
|
5 Star |
3.30 |
|
5 Star |
4.50 |
|
|
Remember that it’s not fair to compare the star ratings of a split air conditioner with a window air conditioner. For example, a 4 star window air conditioner will not have the same efficiency as a 4 star split air conditioner. Most manufacturers are reducing their Window ACs line-ups and focusing more on Split ACs, many of which are inverter based. The manner in which they function leads to better energy efficiency compared to non-inverter models.
How is ISEER calculated?
The idea behind EER and ISEER star ratings is the same. Star ratings is the simplest component when it comes to comparing different AC models. If you are curious to know how ISEER ratio is calculated, we have tried to make the concept simpler for you. You can also read more about it on the official BEE web site.
ISEER rating is the total cooling load (amount of heat removed) to the total amount of energy consumed by the air conditioner. This means, ISEER = Cooling seasonal total load (CSTL) / Cooling seasonal energy consumption (CSEC). The ratio calculated is then used to select the correct star ratings.
Regardless, if you are planning to buy an air conditioner, you can search and compare from a list of air conditioners, click here. The Bureau of Energy Efficiency (BEE) has made it simpler, giving you all the details on cooling capacity, power consumption, seasonal energy consumption and star ratings of the AC model you are looking for.
