What Size Air Conditioner Do I Need?

Whether you’re building a new home or upgrading your existing HVAC system, there is one question you're bound to consider: what size air conditioner do I need? Selecting the ideal air conditioning size is a balancing act. Too large, and you could encounter poor humidity control and exorbitant energy costs. Too small, and the unit might struggle to reach comfortable temperatures on extremely hot days. Appropriate air conditioner sizing is essential to enjoy an efficient, cost-effective and comfortable cooling experience.

The Importance of Sizing Your Air Conditioner Correctly

Ensuring your air conditioning can generate the perfect cooling capacity is a matter of comfort and cost savings. Here’s why you shouldn’t just guess the appropriate air conditioning system size:

  • Humidity control: An oversized unit cools too quickly, reducing humidity removal and rendering your home clammy. A right sized air conditioner will manage indoor humidity levels more successfully.
  • Even temperatures: A properly sized air conditioner disseminates cool air evenly and reduces unpleasant temperature changes between cycles.
  • Peak day performance: An undersized system will struggle to achieve the target temperature on hot summer afternoons, so you need a unit powerful enough to keep up with cooling demand.
  • Proper cycling: Air conditioners start up and turn back off with sufficient run time during each cycle. Units that are larger than you need cycle too quickly, causing40 unnecessary wear and tear. On the other hand, an undersized system runs constantly, which may cause overheating.
  • Manageable utility bills: Cycling issues caused by selecting the wrong size of air conditioner lead to higher electricity bills. However, a unit that is the proper size will work effectively and keep your utility bills in check.

Understanding Air Conditioner Size

Cooling capacity is calculated in British thermal units (BTUs). A BTU is a standard unit of energy that conveys the amount of heat an air conditioner can remove every hour. Most room air conditioning units range from 5,000 to 18,000 BTUs. Because central air conditioners are more powerful, they’re typically measured in tons. A one-ton system is equivalent to 12,000 BTUs. Generally, central air conditioning models range from 1 to 5 tons.

Sizing a Room Air Conditioner

When considering 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 between 350 and 550 square feet may need an 8,000 to 12,000 BTU unit.
  • A spacious room or open area of 550 to 1,000 square feet may require a 12,000 to 18,000 BTU unit.

These general recommendations don’t consider additional 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 precise calculation, reach out to an HVAC professional from TML Service Experts.

Sizing a Central Air Conditioner

Choosing the perfect size of central air conditioner begins with the home’s square footage, but accurate sizing requires a more in-depth look. HVAC specialists rely on load calculations detailed in Manual J to determine a home’s specific cooling requirements. Here are the factors that professionals consider:

  • Square footage: The size of your home significantly affects its AC requirements, with more sizeable homes generally requiring more cooling capacity.
  • Local climate: Where you live affects your cooling preferences as well. Parts of the country with sweltering hot, humid summers naturally demand a higher cooling capacity than cooler, drier areas.
  • Interior heat gain: The heat created inside your home is made by people, lights, electronics and appliances. Additional internal heat increases your home’s cooling needs.
  • Insulation levels: The level of insulation in your walls, attic and floors impacts how much heat gets into your home. Well-insulated homes hold cool air more efficiently, which lowers the cooling load.
  • Air infiltration rate: This refers to how much outside air enters through leaks or cracks in the exterior of your home. Homes with a high air infiltration requires more cooling to counteract the warm, humid outdoor air that makes its way into the home.
  • Home orientation and window layout: The direction your home faces determines its sun exposure, which in turn impacts your home’s cooling load. A single-family home 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 ACs are created equal. It’s vital121 to choose a trustworthy brand for durability and longevity.
  • Efficiency rating: The seasonal energy efficiency ratio (SEER) signifies the amount of heat an air conditioner can remove per unit of electricity it consumes. Higher SEER ratings indicate increased efficiency, decreasing your utility bills.
  • Maintenance requirements: Regular maintenance keeps your system working efficiently. Most AC makers suggest yearly tune-ups to catch small problems before they turn into pricey repairs.

Get Expert Help Sizing Your Air Conditioner from TML Service Experts

Choosing139 a suitable air conditioner size can be overwhelming. The Experts at TML Service Experts are here to assist with all your cooling and heating needs. We provide custom cooling strategies to boost home comfort, efficiency and energy savings.

From establishing your exact cooling specifications to helping you browse different brands and efficiency ratings, we’re with you at every step. For help picking out the perfect air conditioner for your home in Boise, call 208-488-4892 today to schedule your appointment with TML Service Experts.

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