Air Conditioner Selection: Understand Tonnage, EER, COP, and Star Rating

It’s a common principle in marketing; that if you can’t make someone understand it, make sure you have confused them.

Every business industry uses this principle. Thus, you see manufacturers using various forms of technical jargon while selling their services or products. A large majority of people cannot even understand what the manufacturer is talking about. It’s an unpalatable reality. Whether you accept it or not, but unfortunately, it’s a fact.

Let’s be honest! Do you know what the meaning of EER, COP, Tonnage, and star ratings is? Thus, the government is helping people with star ratings, high for good and low for poor. In this article, we are trying to explain the expressions that rule these star ratings, so that whenever you plan to choose an air conditioner for your home, you have complete knowledge about the working of the air conditioner system.

Let’s start with the tonnage.

Tonnage

You must have seen people using these “jargons” “I have bought a 1.5-ton AC for my house”. What does that mean? Do you think that means the weight of your AC is 1.5 tons? In that scenario, your wall wouldn’t be able to bear it. The word “ton” refers to the total heat that the conditioner can remove in one hour. The tons are used to measure heat. The heat in some countries is measured in BTUs (British thermal units). The more BTU, the more heat will be removed from the room.

1 ton+ 12.000 BTU per hour. Historically, the term ton was used to refer to the amount of area cooled by 1 ton of ice.

What is the right tonnage to buy an air conditioner?

Right tonnage: there’s no such concept of it. It relies on various factors like the number of appliances, and people in the room, size of the room, season, and the city of usage. In summers, you need higher tonnage because of severe heat. So, consider an AC with higher tonnage if you live in a city where summers are scorching.

What is EER?

Energy Efficiency Ratio, you will hear a lot about this. EER represents the amount of heat removed in 1 hour / the power consumed by the air conditioner. The formula that shows EER is= BTU/hr/Watt

This shows that a good amount of heat is removed by the air conditioner per watt; the functionality is good. The higher EER of an air conditioner, the better.

What is COP?

COP stands for coefficient of performance. The higher COP your air conditioner has, the lesser would be the operating cost. This ratio calculates the energy efficiency of heating performance while the EER calculates the energy efficiency of cooling performance. Both the terms are extremely important while choosing an air conditioner. COP has no unit. The connection between COP and EER can be measured with this formula;

EER= COP x 3.412

Star ratings

It is a fact that everything has its price. High star ratings explain the high cost of an AC, excellent efficiency, and higher BEE (bureau of energy efficiency). At the same time, an AC with 1 star shows less cost, low efficiency to cool, and poor performance. So, decide wisely.

In conclusion

We have tried to cover maximum details for you to make an intelligent choice while buying an air conditioner. Now you are equipped with the knowledge to ask the dealer to make sure you have purchased the perfect air conditioner for yourself. Give us a call at 1300 730 896 if are looking for an affordable service to install the air conditioner. QuickAir has expert technicians across Australia who are well experienced with all major brands and types of air conditioning systems.

Ready when you are

Book a licensed technician — same-day, every capital city.

$239 call-out inc GST · fixed price, no surprises · 4.9★ (128 Google reviews)

Other Related Resources

Is It Cheaper to Repair or Replace an AC in Sydney?

In most cases, repairing your air conditioner is cheaper than replacing it when the unit is under 10 years old and the fault is minor. Replacement usually works out cheaper over time when the unit is old, keeps breaking down, or the repair quote climbs past about half the price of a new system. At

Read More »

How Much Does It Cost to Install an Aircon in Sydney? (2026 Guide)

Installing a new air conditioner in Sydney usually costs between $1,800 and $4,800 for a single split system, $4,200 to $8,000 for a multi-split, and $12,000 to $17,000 or more for ducted air conditioning across a whole home. The final price comes down to three things: the type of system you choose, the size of

Read More »

Is It Cheaper to Repair or Replace an AC in Hobart?

In most cases, repairing an air conditioner is cheaper upfront than replacing it. A minor fix often costs a few hundred dollars, while a new system installed in Hobart usually runs into the low thousands. The catch is that repair is not always the cheaper option over time. If your unit is old, breaking down

Read More »