DFW(817) 226-2665 Request Service

How to Choose the Right AC Size

For first-time air conditioner buyers, the process can be a bit overwhelming. If you’re in the market for a new AC unit, you’ve likely heard about different AC sizes and might have seen “BTU” a couple of times. But what does it all mean when it comes to choosing your AC?

What does AC size mean?

The size of your AC unit actually refers to its cooling capacity rather than its physical dimensions. This is measured in British Thermal Units (BTUs) based on the cooling needs of your home. Having a well-sized AC means your system will operate at maximum efficiency, lowering your operating costs and making your home as comfortable as possible.

Manual J Calculations

To calculate the size of your home’s ideal AC unit, we use a Manual J calculation. Some HVAC professionals can do this calculation as well as professional energy auditors. Manual J calculations consider many factors to ensure accuracy, including:

  • House size in square feet
  • Climate/location
  • Number of residents
  • Type and number of windows
  • Heat-generating appliances
  • Insulation
  • Ductwork
  • Sun exposure

As a rule of thumb to get you started on your AC unit search, you can calculate the BTU requirement of your new AC unit using only square footage by multiplying the square footage by 20 BTUs. There are also dozens of free BTU calculators available online. However, calculating AC size is a job best left to professionals to avoid the risk of improperly sizing your new system.

Bigger Isn’t Always Better

Bigger usually means better, but it’s important to understand that this isn’t true for air conditioners. It’s tempting to get a bigger AC using the logic that it will cool even better, but oversized AC units actually struggle with cooling spaces that are too small. This will lead to frequent cycling that wears down your AC much faster than it should, which will likely lead to early replacement.

The same goes for those who wish to save money by getting a smaller AC. It won’t be able to adequately cool the space, making the unit work harder for longer to meet your cooling needs. You’ll never be satisfied with its performance, and it can also lead to faster wear and tear on the unit.

For more information about properly sizing an AC unit or to begin a service request for AC installation, contact Air Clinic DFW today.

Why Choose Air Clinic?

team logo
Professional Team
Our team of technicians are licensed, highly trained and trustworthy. You can count on us to get the job done right the first time.
air clinic ac repair logo
Reliable Service
Locally owned and operated, we strive to offer the best customer service with transparent and upfront pricing.
approval logo
Quality Products
Proud to offer the best products from top HVAC brands including Trane, American Standard and Carrier.

What Our Customers Say

Professional and Knowledgeable

Air Clinic has always been fantastic to work with. Honest, reliable and flexible. They have excellent communication and fair prices. I’ve used them for 8 years now!


Outstanding Job

Ryan, Justin, Austin and Kevin did an outstanding job. The communication among us for the H/VAC exchange was right on point. I would highly recommend this company to family members.


Friendly and Helpful

Fantastic company Andrew and Steven did a great job. Very friendly and helpful on set up.


Reliable and Professional

Service was on time technician very clear with our problem and addressed it. Price quoted was the same price at the end of service.


Professional and Punctual

Bought my AC unit through Lowes and was installed by Air Clinic. They did a great job. They were professional and punctual.