What Size Air Conditioner Do I Need?

Whether you’re building a new home or replacing your existing air conditioning system, there is one question you're guaranteed to ask: what size air conditioner do I need? Buying the ideal air conditioner size is a balancing act. Too large, and you could face poor humidity control and excessive energy bills. Too small, and the unit might not be able to provide comfortable temperatures on sweltering hot days. Proper 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 air conditioning produces the right cooling capacity is a matter of comfort and cost savings. Here’s why you shouldn’t merely guess the ideal air conditioning system size:

Humidity control: An oversized unit cools too rapidly, reducing humidity removal and making your home clammy. A right sized air conditioner will control indoor humidity levels more successfully.
Even temperatures: An efficiently functioning air conditioner circulates cool air evenly and reduces uncomfortable temperature variations between cycles.
Peak day performance: Systems that don't have enough cooling capacity struggle to reach the target temperature on hot summer afternoons, so you need a unit big enough to keep up with cooling demand.
Proper cycling: Air conditioners turn on and off with sufficient run time per cycle. Units that are too large cycle too quickly, resulting in40 additional wear and tear. Conversely, an undersized system runs continuously, which may cause it to get too hot.
Manageable utility bills: Cycling issues caused by installing the wrong size of air conditioner cause higher utility bills. However, a unit that is the proper size will function as designed and keep your utility bills in check.

Understanding Air Conditioner Size

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

Sizing a Room Air Conditioner

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

A room measuring 150 to 350 square feet usually will need to have a 5,000 to 8,000 BTU air conditioner.
A room that is around 350 and 550 square feet should 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 recommendations don’t take into account factors like interior heat gain or sun exposure. For a more precise calculation, seek expert advice from Strogen's Service Experts.

Sizing a Central Air Conditioner

Figuring out the right size of central air conditioner begins with the home’s square footage, but accurate sizing involves a more in-depth look. HVAC professionals rely on load calculations outlined in Manual J to determine a home’s unique cooling requirements. Here are the factors that professionals consider:

Square footage: How large of a home you have significantly affects its cooling requirements, with more sizeable homes generally requiring more cooling capacity.
Local climate: Where you live impacts your cooling preferences as well. Parts of the country with very hot, humid summers naturally demand a higher cooling capacity than cooler, drier areas.
Interior heat gain: The heat released inside your home is made by people, lights, electronics and appliances. Higher internal heat increases your home’s cooling needs.
Insulation levels: The quantity of insulation in your walls, attic and floors impacts how much heat gets inside. Well-insulated homes retain 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 into the 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 home with sprawling south-facing windows absorbs more heat and necessitates a bigger 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 essential121 to select a reputable brand for durability and longevity.
Efficiency rating: The seasonal energy efficiency ratio (SEER) signifies how much heat an air conditioner can remove per unit of electricity it consumes. Higher SEER ratings represent greater efficiency, decreasing your utility bills.
Maintenance requirements: Regular maintenance keeps your system running efficiently. Most air conditioning manufacturers encourage yearly tune-ups to find and fix small problems before they turn into expensive repairs.

Get Expert Help Sizing Your Air Conditioner from Strogen's Service Experts

Selecting139 the best air conditioner size can be stressful. The Experts at Strogen's Service Experts are here to help. We can provide you with custom cooling remedies to optimize home comfort, efficiency and energy savings.

From calculating your exact cooling requirements to helping you browse different brands and efficiency ratings, we’re at your side at every step. For help choosing the perfect air conditioner for your home in Rochester, call 603-923-4570 today to schedule your appointment with Strogen's Service Experts.