What Size Air Conditioner Do I Need?

May 16, 2022

If you’re looking for a new split-system air conditioner, its size should be based on your home’s square footage and a few other factors. Since an HVAC system that’s too small will struggle to cool your home and a system that’s too large will break down faster, it’s important you know how to pick an air conditioner in the right size. Before you splurge on a full AC replacement, review a few sizing tips to make sure you purchase the best system possible.

3 Tips for Picking the Right Sized Air Conditioner

Once you know the basics of air conditioner sizing, choosing the right-sized air conditioner for your home isn’t difficult. To ensure you pick the best AC possible, use the following three tips:

1. Understand BTU Ratings and Tonnage

As you look for an AC system, you need to know two key measurements—British thermal units (BTUs) and tonnage. Learn more about these measurements and why they matter below:

  • BTU: A BTU refers to the amount of heat required to increase a pound of water’s temperature by a single degree Fahrenheit. In an AC system, a BTU rating will show how much heat your system can remove within an hour. 
  • Tonnage: Any AC you look for will have a tonnage measurement. Instead of referring to the system’s weight like you might expect, an AC’s tonnage measures its cooling ability. For example, a single-ton system will cool 12,000 BTUs over an hour, while a three-ton system will cool 36,00 BTUs per hour. As a result, an AC system with a higher tonnage is better for larger homes, while an AC system with a lower tonnage is more appropriate for smaller homes.

2. Calculate Your Needed Tonnage and BTU Rating Using Your Home’s Square Footage

Your home’s square footage is the primary factor that determines your needed tonnage and BTU rating. Since a larger home will require more cooling power from an AC and a smaller one will need less, it’s critical you take your home’s square footage into account while picking a new system. 

Once you know your home’s square footage, you can use a simple calculation to get a better idea of the right size you’ll need for an AC. To calculate your needed AC size, multiply your house’s square footage by 25, and then divide that number by 12,000 (the amount of BTUs in one ton). Finally, take the result and subtract 0.5 from it to receive the required tonnage for your AC. 

For example, if you have a 1,000-square-foot home,  multiply 1,000 by 25, and your result will be 25,000. After dividing 25,000 by 12,000, the total will be 2.083, and after subtracting by 0.5, you’ll get 1.583. This final result means you’ll need at least a 1.5-ton unit to cool your home. 

3. Schedule a Professional Inspection

While the calculation found above can give you a general idea of your needed AC size, it won’t take into account a few other factors that can affect proper sizing. For example, a home’s ductwork, amount of sun exposure, quality of insulation, and geographic climate can all impact the amount of BTUs an HVAC system requires to properly cool your home.

Due to all these factors that can affect your needed HVAC system, it’s a good idea to schedule an inspection from an HVAC professional. One of these professionals will evaluate your home’s needs based on all the factors that can impact the effectiveness of a new HVAC system. This inspection will likely reveal different features of your home that you’d likely never spot on your own and help you choose the perfect HVAC system for your home’s unique needs.

Choose Newcomb and Company for Air Conditioner Installation in Raleigh

If you need a new AC system and live in Raleigh, Wilmington, or the surrounding areas, turn to Newcomb and Company. Once you schedule an appointment, our team will perform a full inspection of your home, ensuring your new AC is properly sized and ready to cool your home effectively all year long. Alongside recommending standard AC units, we can even design a custom system for you to maximize your home’s energy efficiency and your AC’s performance.

Find out more about our AC replacement and installation services today. If you have any questions or are ready to schedule an appointment, please contact us.

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