What Size Air Conditioner Do I Need? (Bigger Is Not Always Better)

Summer is on the horizon, and the question looms: What size air conditioner do you need to keep your home comfortable without breaking the bank? While you might think bigger is better, that’s not always the case. Finding the right size air conditioner is crucial for efficient cooling and energy savings. At Hearn Plumbing, Heating & Air, we can help you make the right choice for your cooling needs. Call us today at (440) 428-3905 to schedule an AC sizing consultation with straightforward pricing.

The Importance of Proper Sizing

Choosing the correct size air conditioner is essential for various reasons. An incorrectly sized AC unit can lead to:

  • Energy Inefficiency: Both oversized and undersized units will consume more energy, increasing your electricity bills.
  • Ineffective Cooling: An undersized unit will struggle to cool the home, while an oversized one will cycle on and off too quickly, failing to remove humidity effectively.
  • Shortened Lifespan: Incorrect sizing puts additional stress on the AC unit, leading to frequent repairs and a shorter lifespan.
  • Discomfort: Poorly sized AC units can create uneven temperatures and humidity issues, making your home less comfortable.

The Science Behind Sizing

When it comes to air conditioner sizing, professionals use the term “tonnage” to describe the unit’s cooling capacity. Contrary to popular belief, this doesn’t refer to the weight of the AC unit, but rather its ability to remove heat. One ton of cooling capacity can remove 12,000 British Thermal Units (BTUs) of heat per hour.

Factors That Affect AC Sizing

Here are some factors that HVAC experts consider while determining the appropriate AC size for your home:

Square Footage

The most basic variable is the total area you need to cool. A simple calculation based on square footage can give you a rough estimate of the required tonnage.


Hotter climates demand higher cooling capacity, while milder climates may require less.


Well-insulated homes can get by with a slightly smaller unit because they are better at retaining the cool air.

Windows and Doors

The number, type, and placement of windows and doors in your home also affect how much cooling is needed.


More people in the home mean more metabolic heat, which in turn requires more cooling.

How to Calculate the Right Size

To get an accurate size requirement, many professionals use Manual J load calculations, which take into account all the aforementioned factors. It provides the most reliable way to determine the optimal AC size for your home.

Straightforward Pricing

Once you’ve determined the right size, the next step is installation. At Hearn Plumbing, Heating & Air, we offer straightforward pricing for all our services, including AC installation. You’ll receive a detailed estimate upfront, so there are no surprises later.

Why Bigger Isn’t Always Better

It might be tempting to go for a bigger unit, thinking it will cool your home faster. While it may cool quickly, it will cycle on and off frequently, leading to energy inefficiency and failing to dehumidify your home adequately.

The Benefits of Proper Sizing

  • Energy Savings: A correctly sized unit operates at peak efficiency, saving you money on your energy bills.
  • Comfort: Properly sized AC units deliver more consistent temperatures and better humidity control.
  • Longevity: A unit that isn’t constantly cycling on and off will generally have a longer lifespan, requiring fewer repairs.
  • Environmental Impact: Energy-efficient units are not only good for your wallet but also better for the environment.

Choosing the right size air conditioner for your home is a decision that will affect your comfort, energy bills, and the longevity of your unit. By understanding the factors that go into this decision and working with a trusted professional, you can ensure that you make the best choice for your home and your family. At Hearn Plumbing, Heating & Air, we’re committed to helping you find the perfect fit.