The A/C tonnage figure refers to the amount of cooling your air conditioner can supply to maintain optimum comfort. When you hear HVAC contractors or others referring to the sizing of an air conditioner, they’re not talking about its physical dimensions in feet and inches. They’re referring to its BTU tonnage—the actual volume of cooling it’s designed to generate under controlled conditions.

Why Tonnage Matters

It’s useful to know the tonnage specification for your air conditioner if you’re about to start shopping for a replacement. It helps you comparison shop among different makes and models of a similar specification.

However, the tonnage of your present unit should never be the only factor in choosing an adequate replacement. Conditions and cooling requirements in a home change over the years. Therefore, the tonnage of an older, existing air conditioner may not be right for your house today.

Because both over-sized and under-sized A/C units tend to run far less efficiently and cool less effectively, a formal cooling load calculation should be performed by a qualified HVAC professional to accurately determine the A/C tonnage currently required in your home for optimum energy-efficiency and cooling performance.

Finding The Tonnage Spec

To locate the tonnage of your existing air conditioner, look at the manufacturer’s data plate, usually affixed to the side of the A/C outdoor condenser unit. The Model Number listed on the plate will usually be a string of numbers and letter, separated into sections. Look for a section that begins with “0” followed by a two-digit even number between 18 and 60. Divide that two digit number by 12—which stands for 12,000 BTUs, a “ton” of cooling—to determine the tonnage. For example, if the section in the Model Number reads 048, dividing 48 by 12 produces 4. This means your air conditioner was a 4-ton unit at the time it was manufactured.

For more about determining A/C tonnage—and making sure it’s adequate for your home cooling requirements today—contact the pros at Powers Heating & Air.

Our goal is to help educate our customers in Peachtree City, Georgia and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 770-487-2040.