How to Save Money on Air Conditioning by Understanding EER

WA1010E Image2If you've decided to get ahead of the heat by adding a portable air conditioner to your summer shopping list, you may have encountered a perplexing array of numbers that leaves you scratching your head. BTUs? Watts? EER?

If you're not familiar with these terms, you may not know how important they are to choosing the right room air conditioner. That's why we're here, to help fill in these puzzling blanks so you can be confident when you make your portable AC purchase.

What's an EER?

EER stands for Energy Efficiency Ratio. Don't let slippery sales people or technical sites confuse you about how simple this really is. Simply put, an EER number basically tells you how much energy the air conditioner uses relative to how much cooling it is capable of.

When you compare EERs on room AC units, you can easily tell which one will save you money on your electricity bill, while still providing all the cold air you need to stay cool.

How do you calculate an energy efficiency ratio?

To figure out an EER, we have to look at both the BTUs and the Ws of a unit.

  • What is a BTU?
    BTU stands for British Thermal Unit, and it is a measure of thermal heat energy used across the heating and air conditioning industry. Most room air conditioners fall in the range of 8,000 to 14,000 BTUs per hour.
  • What is a W?
    W is an abbreviation for Watt. A watt is a standard unit of electricity - you've probably seen the word when buying light bulbs. For electrical power, one watt is equal to one ampere of current per second.

Once you know these two numbers, you can easily calculate the EER for any portable AC by dividing the number of BTUs by the number of Watts.

AC-10000E Image1Example Scenario

Let's say that you're shopping online and you find two great AC units, Unit A and Unit B. Both A and B are listed as 10,000 BTU air conditioners, capable of cooling rooms up 325 square feet.

When you check the specifications, you discover that Unit A uses 1,200 W and that Unit B uses 1,000 W.

 Unit AUnit B
BTUs10,000 BTU10,000 BTU
Watts1,200 W1,000 W
EER
 (BTU / W)
8.310.0

Now you have two choices: should you choose Unit A with an EER of 8.3? Or Unit B with an EER of 10?

Which energy-efficiency rating is better?

The higher EER is always better. If you go with unit B, you'll have a more energy efficient system. Not only will this save you money on your monthly utility bills, you will be helping the environment by reducing greenhouse emissions.

The national appliance standard requires all room air conditioners to have a minimum EER of 8. An EER of 10 and above is considered good, but newer models can reach outstanding energy efficiency ratios of 13 and above.

cashhouseWhat about cost?

It's true, portable air conditioners with higher energy-efficiency ratings cost more to buy than less efficient models. So the next question you want to ask yourself before you make a final decision is: Which unit is a better investment over time?

Let's assume the price difference between Unit A and Unit B is $100. A hundred dollars may seem like a lot, but is it really? If you take into consideration how much energy the more efficient air conditioner will be saving you in the long run, the answer is not so clear-cut. Remember that less energy used means a lower electricity bill, and a lower electricity bill means less money coming out of your wallet every month.

The unit with the better EER may seem like an expensive purchase, but it is actually a money-saving investment that will keep you cool and fresh throughout sweltering hot summers.

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