Unbearable heat, troublesome humidity and related irritation and frustration is induced by hot and humid weather. The best way to beat extreme heat is to simply install a conditioning device for air otherwise known as Air Conditioner.
As with any purchase there are many things to consider before buying such an appliance. For instance you need to ascertain the cooling requirements, fan speed, form factor needs, budget, and of-course the energy efficiency rating being targeted. However we are going to understand the difference between 2 widely available energy efficiency rated ACs which are 3 star and 5 star.
How are ratings done.
Why are ratings important in appliances such as Air conditioners.
The star ratings is given on a scale of 5 with 5 being the most energy efficient appliance. The BEE (Bureau of Energy Efficiency) assigns a star rating on the basis of its performance relative to its energy consumption to all electronic appliances to help buyers know the energy efficiency and what will be their expected electricity consumption on an average.
The star rating is broadly derived from 2 factors in case of an Air Conditioner.
- What is the cooling capacity or cooling speed ?
- How much power does the AC use achieve the said cooling?
All things remaining same a 5 star rated AC will consumer much less energy and electricity than a 3 star AC to cool down a room.
All appliances such Air Conditioners have a BEE star rating sticker on the front affixed on the front. The colored stars on them denote the star rating. If all the stars have are colored it means the appliance has a full 5 star rating. Similarly 3 colored stars infact mean that the appliance has a 3 star energy efficiency rating.
Understanding the difference between 3-star and 5-star Ac
Higher cooling capabilities
This basically means that the AC would have higher cooling capacity. Although in reality while cooling capacity can be same between 2 Air conditioners their energy consumption could be varied. Usually inverter ACs possess high cooling capabilities besides being able to scaled down the power consumption as per situation.
Low power consumption
Generally speaking a 5 star rated split AC would on an average consume around 25% less electricity from their 3 star rated counterparts. This essentially means that these are highly recommended for extensive usage or for places where Air Conditioner is used more or less through out the year.
Calculation!
To be able to calculate energy consumption of any appliance a few key details are needed, which are as follows.
- The ampere consumption of AC usually denoted by letter ‘A’
- The total hours the AC is used
- cost of 1 unit of electricity consumed for your connection.
Once you have the above information, you can use the following formula to calculate the power consumption of your appliance such as an Air Conditioner.
Units of electricity consumed per month = Amperage x Voltage (usually 200) x daily run time of the unit x no of days in a month. Result to be divided by 1000 to get kWh consumed.
Let’s assume you run your AC for 8 hours a day and its Ampere rating is 7A. So, the total power consumption of the AC as per the above formula will be 7 x 220 x 8 x 30 = 369.6 units in a month.
Therefore the total energy bill for the said Air Conditioner if per unit cost is 5 rupees would be, 369.6 x 5 = Rs. 1848₹/-
Factors affecting Electricity Consumption in Air Conditioners
Lots of factors influence energy utilization and electricity consumption in Air Conditioners such as-
- Air Conditioner Type
- Ambient temperature temperature
- Room size
- Features such as Wi Fi
- Fan speed
So which AC should you buy?
It is obviously clear that a 5 star rated AC be it split or window consumes less electricity than their 3 star variants. It is also evident that the prices of 5 star rated ACs is high compared to 3 star ACs and in some cases these cost upto 40% more than the 3 start rated ACs. Good 5 star Air conditioners cost around 40000 rupees in India. LG makes some wonderful Split ACs. View best AC brands here.
Therefore it is not easy to offset the initial extra expenditure on a 5 star AC. Having said that if the AC is to be used extensively and for a larger share of the year then buying a 5 star AC would make more sense.
However if AC usage is limited to a few hours a day for a few months a year or if the per unit electricity cost is low for your electricity connection then it makes sense to save money and a 3 star rated Air Conditioner.