If you have an air conditioner (AC), and you want to save energy, it is vital to consider its energy-efficiency ratio (EER). You can check the EER on the air conditioner’s specification sheet. The rating is invaluable in helping you know whether the device meets your efficiency requirements or not.
Note that you will be incurring unnecessary expenses when your AC efficiency is poor. That is why knowing about the energy-efficiency ratio is so useful, as it can inform you if your AC is energy efficient or not.
Checking Energy Efficiency the Right Way: Homeowner Edition
Before we answer “How to check energy efficiency rating,” it’s important to know that the higher the EER of an AC, the greater the amount of cooling it will generate per kWh of energy supplied. In other words, it provides more cooling with lower energy consumption. That makes an AC with a higher EER rating more efficient and sustainable.
The question now is, “How do you compute the EER rating of your air conditioner?” It’s simple, but it depends on whether the air conditioner’s cooling capacity is rated in BTU or kW. Firstly let’s look at BTU.
Calculating EER With BTU
Divide an AC’s capacity (e.g., 6000 BTU, 18,000 BTU) by its power (e.g. 1000W, 1,400W, 1,800W) with following formula:
EER rating = Capacity (in BTU) / Power (in W)
Here is an example. You have a 14,000 BTU mini split air conditioner powered by 1,400W. Compute the EER in the following way:
EER rating = 18,000 BTU / 1,400W = 12.86
The calculation says that the air conditioner provides a 12.86 BTU of cooling for every 1.4W of energy supplied. You can say that is better than an 18,000 BTU, 1,800W AC with an EER rating of 10. That means that the AC would only provide 10 BTU of cooling instead of 12.86 BTU for every 1.4W of energy.
Note that the recommended EER rating is at least 14. So if your AC’s ratio is higher than that, then it is energy efficient. On the other hand, if your AC had a EER ratio of well below 14, you should consider replacing it with a better AC with a higher EER.
Calculating with COP With the Cooling Capacity Stated in kW
Now let’s look at an air conditioner where the cooling capacity is rated in kW. We are interested in the coefficient of performance (COP) instead of the EER.
COP = Cooling capacity (kW) / Power in (kWh)
We would consider a good COP to be one higher than 4. If you are mathematically inclined, you can convert a COP to an EER by multiplying the COP by 3.4.
You should understand that the EER is calculated via a standard set of parameters. These are relative humidity (50%), outdoor temperature (95F or 35C), and indoor temperature (80F or 26.7C). That means that the calculated EER isn’t constant all the time. The EER is also based on the air conditioner being fully loaded. In reality, most air conditioners operate in part-load conditions most of the time.
You can buy an AC at the benchmark of an EER of 14 or COP of 4, but its not advisable to go lower than this. If you can find one with an even higher EER rating and at an almost similar price, go for it!
Too Technical for the Average Homeowner
But what if you don’t want to bother computing for the EER rating? You can always inquire at the company or store where you bought the unit. Don’t hesitate to ask their technician or sales person. If you’re buying from an online platform, it’s not wrong to hit their question tab or send them an email for recommendations. Besides, most manufacturers already publish the EER rating for each of their models.
Why Is Checking for Energy Efficiency Ratings Important
Checking your AC’s energy efficiency comes with several benefits that shouldn’t be ignored. Here are some of them:
Reduce Electrical Bills
An energy-efficient air conditioner consumes much less power compared with conventional models. That means it will have lower electricity costs and help you save money for other purposes. Using efficient ACs can lessen your costs by as much as 30%.
Helps in Environmental Preservation
One of the simplest ways to help save the environment is to use more energy-efficient devices such as air conditioners. Since these devices do not consume as much energy, the use of fossil fuels in generating electricity is reduced. That means fewer greenhouse gases polluting the atmosphere. With lower greenhouse gas emissions, efficient ACs play a significant role in mitigating climate change.
Some countries or states offer rebates and incentives to those who install energy-efficient air conditioners. This is a trend, especially in Western countries leading the global campaign for sustainable living. Of course, you have to do your part by researching these perks available in your locality. You can also seek assistance from AC providers.
Be a Better Purchaser
In most cases, consumers look at the price first before buying an item and nothing else. Sadly, cheap products commonly lack in quality and can incur higher total lifetime costs for the buyer. Keep in mind that cheap models may also not last as long. That means you could need to spend more to maintain the cheap AC or have to shell out a significant amount to get a replacement. While a high efficiency air conditioner may cost a little more, the lifetime total cost of ownership is usually much lower.
How to check the energy efficiency rating? Again, look at its specification sheet or ask the sales person for advice – they are more than eager to recommend you better alternatives. Remember, a higher energy-efficiency rating means a more environmentally friendly air conditioner. You may need to spend more, but you won’t have to worry so much about your electricity bill. That makes energy-efficient ACs more budget-friendly in the long term.