Get Familiar With Tonnage And Efficiency To Buy The Right Air Conditioner

Summer is round the corner and heat is increasing each season. People seek to buy a good AC that suits their comfort and budget. It is crucial to get familiar with tonnage and efficiency for saving on power and utility bills.

Size and tonnage

Tonnage does not mean weight of the AC unit. Ton is referred to the unit’s capacity of removing heat within an hour. Heat removes is calculated in BTU or British thermal Unit. High BTU means great cooling capacity suitable to cool large space.

Generally, 1 ton unit = 12,000 BTU/hr and 3 ton = 36,000 BTU/hour and so on.

Now, you will need to determine right tonnage. This depends on factors like room size, appliances in room, number of people using that space, location of your home and more.

Even climatic changes need to be considered like in peak summers, more tonnage is required to handle the increased heat. Even day and night tonnage needs differ. When you select tonnage, keep peak summer heat in mind during choosing.

AC size selection matters because undersized unit does not cool efficiently and oversized unit consumes extra power. If you opt for fixed speed AC designed with peak summer day in mind then it will be oversized most of the times.

Use to compare tonnage difference between fixed speed and inverter AC. It helps to make a purchase decision, for example if you invest in 5-star BEE rating 1.5 ton Voltas split AC for a room that really needs 1.2 tons cooling capacity then you can buy BEE 3 star 1.2 ton unit to avoid over-sizing and extra electricity usage.


Efficiency of ACs use the terms

EER or Energy Efficiency Ratio

EER = heat amount eliminated in an hour in proportion to electricity consumed.

EER = BTU/hr/Watt

1kW = 3412 BTU/hr

COP = heat removed in Watt proportionate to power consumption in Watt.

Just like EER, the higher the COP, for better performance.

BEE or Bureau of Energy Efficiency mandates each AC to hold this label.  Stars are given from one to five. High star numbers indicates high EER or efficiency. BEE revises each ACs star rating periodically. Therefore a 5- star AC sold last year turns into 3-star in existing year after revision. Label validity is also printed. When you check the BEE-star rating then also check EER. For example, it is possible that AC having 3.39 EER has 3-star BEE label and another unit with 3.4 EER has 4-star BEE label. You see with increase in every star rating, the chances of saving 14% also increases.

Inverter technology split AC is flexible and can save 15% to 20% more than BEE 5-star rating. Therefore manufacturers claim 60% savings on AC units with inverter technology.

More stars more savings and more capital cost

Obviously, 5-star AC price will be more than 1-star AC cost, even if company is same. Inverter technology AC will cost even more. 5-star AC uses less power in comparison to 1-star AC of same tonnage to cool a room of same size. You save on operation cost, so the upfront cost of buying the high star AC gets balanced.