What Size Air Conditioner Do I Need?

Whether you’re building a new home or upgrading your existing heating and cooling system, there is one question you’re definitely going to consider: what size air conditioner do I need? Selecting the right air conditioning size is a balancing act. Too large, and you could experience poor humidity control and exorbitant energy bills. Too small, and the unit might fail to reach comfortable temperatures on extremely hot days. Correct air conditioner sizing is crucial to enjoy an efficient, cost-effective and comfortable cooling experience.

The Importance of Sizing Your Air Conditioner Correctly

Ensuring your AC produces the right cooling capacity is a matter of comfort and cost savings. Here’s why you shouldn’t simply guess the correct air conditioner size:

    • Humidity control: An oversized unit cools too rapidly, preventing humidity removal and making your home clammy. A correctly sized air conditioner will manage indoor humidity levels more efficiently.
    • Even temperatures: A properly sized air conditioner circulates cool air evenly and reduces uncomfortable temperature fluctuations between cycles.
    • Peak day performance: A system that is too small can struggle to reach the target temperature on hot summer afternoons, so you need a unit powerful enough to keep up with cooling demand.
    • Proper cycling: Air conditioners turn on and off with adequate run time for each cycle. Units that are larger than you need cycle too quickly, causing increased wear and tear. On the other hand, an undersized system runs continually, which may cause overheating.
    • Manageable utility bills: Cycling troubles caused by installing the wrong size of air conditioner result in higher electricity bills. However, a unit that is the recommended size will work as designed and keep your utility bills in check.

Understanding Air Conditioner Size

Cooling capacity is measured in British thermal units (BTUs). A BTU is a standard unit of energy that conveys the amount of heat an air conditioner can remove in one hour. The majority of room air conditioning units range from 5,000 to 18,000 BTUs. Because central air conditioners are bigger, they’re usually measured in tons. A one-ton system is proportionate to 12,000 BTUs. Many central air conditioning models range from 1 to 5 tons.

Sizing a Room Air Conditioner

For window or portable air conditioners, the right size mostly depends on the room’s square footage. Measure the area—length x width—and match it to the appropriate BTUs:

    • A room measuring 150 to 350 square feet usually will require a 5,000 to 8,000 BTU air conditioner.
    • A room measuring between 350 and 550 square feet may need an 8,000 to 12,000 BTU unit.
    • A large room or open area of 550 to 1,000 square feet may necessitate a 12,000 to 18,000 BTU unit.

These general guidelines don’t account for factors like interior heat gain or whether or not you have any shade trees around your home to block out the sun. For a more exact calculation, contact a cooling specialist at Service Experts Heating, Air Conditioning & Plumbing.

Sizing a Central Air Conditioner

Choosing the right size of central air conditioner begins with the home’s square footage, but specific sizing involves a more in-depth look. HVAC specialists rely on load calculations explained in Manual J to determine a home’s specific cooling requirements. Here are the elements that technicians will examine:

    • Square footage: The size of your home greatly affects its AC requirements, with more sizeable homes generally requiring more cooling capacity.
    • Local climate: Where you live impacts your cooling preferences as well. States with very hot, humid summers normally demand a higher cooling capacity than cooler, drier regions.
    • Interior heat gain: The heat released inside your home is made by people, lights, electronics and appliances. Increased internal heat raises your home’s cooling requirements.
    • Insulation levels: The amount of insulation in your walls, attic and floors influences how much heat gets into your living space. Well-insulated homes keep cool air more efficiently, which lowers the cooling load.
    • Air infiltration rate: This relates to how much outside air penetrates through leaks or cracks in the exterior of your home. Homes with a high air infiltration requires more cooling to combat the warm, humid outdoor air that sneaks through the walls and into your home.
    • Home orientation and window layout: The direction your home faces determines its sun exposure, which in turn can change the required cooling load. A single-family dwelling with very large south-facing windows absorbs more heat and requires a larger air conditioner than a north-facing condo.

Other Factors to Consider When Buying an AC

Besides knowing what size air conditioner you need, consider these additional factors when installing a new air conditioner:

    • Brand: Not all cooling systems are created equal. It’s essential to buy a trusted brand for durability and longevity.
    • Efficiency rating: The seasonal energy efficiency ratio (SEER) indicates the total heat an air conditioner can take out per unit of electricity it consumes. Higher SEER ratings indicate greater efficiency, reducing your utility bills.
    • Maintenance requirements: Regular maintenance keeps your system operating correctly. Most AC manufacturers suggest yearly tune-ups to find and fix small problems before they turn into costly repairs.

Get Expert Help Sizing Your Air Conditioner From Service Experts Heating, Air Conditioning & Plumbing

Finding a suitable air conditioner size can be stressful. The Experts at Service Experts Heating, Air Conditioning & Plumbing are here to assist with all your cooling and heating needs. We offer custom cooling strategies to optimize home comfort, efficiency and energy savings.

From establishing your unique cooling needs to helping you browse different brands and efficiency ratings, we’re with you at every step. For help choosing the perfect air conditioner for your home in the U.S., call 866-397-3787 today to schedule your appointment with Service Experts Heating, Air Conditioning & Plumbing.

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