The Two Critical Facts You Must Know About Your Air Conditioner

For the vast majority of the United States, air conditioners are a near necessity. As the years have progressed, a higher percentage of homes have gotten them, and older homes have been retrofitted.

If you have an air conditioner to cool your house, there are two critical specifications that you must know. These facts are important when you are shopping for a new AC unit, and are equally important when trying to get a handle on your current electricity bills.

Further, these two facts are often confused, resulting in homeowners spending too much on a AC replacement.
What are these two facts? Well, these facts are actually specifications (specs) on your AC unit.
The first you must know is the cooling capacity of your AC, measured in tons. A “ton” is equivalent to 12000 BTU/hour. That value is pretty abstract (i.e. how do you know how many BTU/hour your house needs to keep cool?), but it is a useful comparative metric. Common central AC units range from 3 to 5 tons.

The second key spec is the efficiency, rated in SEER (Seasonal Energy Efficiency Ratio). This ratio is actually pretty basic – it measures the total cooling produced over a typical season, divided by the amount of energy consumed. Thus, a higher SEER value means a more efficient unit.

State of Confusion, and a Simple Definition

Many homeowners confuse these values and end up asking for too large of an AC. And some unscrupulous contractors try to turn a homeowners limited familiarity with these terms into sales opportunities.

To avoid these pitfalls, think of it this way:

Tons directly relates to the size of your home. Unless you’ve added on or your AC unit was previously undersized, you should never have to buy a large AC unit.

SEER directly relates to the efficiency of a unit. It does NOT mean more cooling capability. It does allow you to compare the efficiency of units of equal size (tons).

Put It To Practice

If you are looking for a new AC unit, it is important to understand the current size (tons) and efficiency of your unit. With a little luck the model information will still be readable on the unit itself, and Google can help you figure it out. If you can’t read the model, you should be able to ask your servicer.

When its time to get a new AC, you’ll likely want to get the same size (tons) as your older unit.

My AC has trouble keeping my house cool. What now?

But what if your current AC has trouble keeping your house cool? This may be a sign that you need a larger AC unit, but you may also have other problems. The questions to consider are:

• Has your AC always had trouble 'keeping up' on hot days? If not, then the size is probably OK, and the recent problems might be something else.

• Has your AC been serviced recently? Perhaps there is a coolant blockage or it needs to be recharged. Older units should be checked annually to keep them running at their most efficient levels.

Its time for me to replace my AC unit. How can I lower my electricity bills at the same time?

And if you want to lower your electricity bills, you should look into a higher SEER AC unit, and NOT a larger (higher tonnage) unit. In fact, stretching your budget to get an extra SEER or two usually pays for itself within a few years.