How is the Sizing Capacity of an AC Unit Measured


Thinking of buying a new air conditioning unit this year? If so, it’s important to understand how the sizing capacity of an AC unit is measured. As a leading provider of AC service, Del-Air offers the following information about choosing the right AC model for your home’s size and family’s needs.

Understanding AC Capacity

Capacity is the ability of an AC system to heat or cool a given amount of space. Typically, heating capacity is expressed in BTUs, or British Thermal Units. A BTU is the amount of energy needed to change the temperature of one pound of water by one Fahrenheit degree. On the other hand, cooling capacity is specified in tons, or a measure of the system’s ability to cool. Manufacturers size heating and cooling systems according to their tonnage, with one ton being equal to 12,000 BTU/H. Most residential systems range from one to five tons.

If you want to ensure your family’s comfort throughout all four seasons, the correct sizing of AC equipment is crucial. The Del-Air technicians will consider the size of your house, as well as the number of residents, when recommending new AC units. Additionally, they might take into account factors like the amount of sun or shade rooms get.

While homeowners are often tempted to buy the biggest AC available, the truth is that oversized systems don’t improve cooling capacity. In fact, the opposite is often true. Not only does oversized equipment cost more to purchase, but operational rates are also higher. Further, oversized equipment will not run as frequently or as long when it does run, a situation known as short cycling, which accelerates the wear and tear on your equipment. ACs that are too big tend to be less energy efficient than properly-matched capacity units. Finally, systems that are too big cool the room too quickly, without removing the accompanying humidity from the air. The end result is a room that is damp and generally unpleasant.

Just as buying oversized AC units is a mistake, homeowners should avoid purchasing undersized equipment. Systems that are too small work longer and harder to meet your comfort demands during temperature extremes. This results in lower energy efficiencies, less comfort, and the potential for premature equipment failure.

Contact Del-Air for AC Service

Trust the professionals at Del-Air to perform a home “load calculation” to determine the correct size heating and cooling system for your home. Call us today for expert AC service at (855) 972-9943, or schedule your consultation online.