← All articles

What Size Ductless AC Do I Need For My Texas Home?

May 07, 2021

Ductless AC units operate very differently from a central AC system, which changes the requirements for determining the proper size model.

You’ll want to hire an expert HVAC technician who will do a proper “load calculation” for your room or area. It is the best way to go to make sure it’s done correctly because many factors go into sizing a ductless AC unit.

In this article, we will break down the benefits of properly sizing the AC unit as well as the process that an HVAC tech will use for the sizing.


Want to have a licensed expert properly perform a load calculation for your new ductless AC system? You can trust our experts to install your ductless AC the right way—the first time.


Benefits of sizing

The importance of having your ductless AC unit correctly sized cannot be overstated. If the sizing is incorrect, your AC will not be able to thoroughly keep your home or room comfortable and you’ll have to spend money resizing and reinstalling the system.

If you get a unit that is too small, the unit will have to run constantly because it is straining itself to cool the room. This means:

On the other extreme, if you get a unit that is too large, the ductless AC system will turn on and quickly cool the room, and then shut itself off. Due to this short-cycling (i.e. constantly turning on and off), the oversized unit produces the same consequences as a unit too small.

  • Uneven temperature throughout the room
  • Extreme humidity in some rooms because it can’t properly pull moisture out of your indoor air
  • High utility bills
  • Frequent repair
  • Decreased unit life expectancy

In short, you can see that units that are too large or too small have similar consequences.

What is a “load calculation?”

A “load calculation” is a bunch of variables that an HVAC technician evaluates to determine the BTUs—or size—of the ductless AC unit.

Here are some of the variables an experienced HVAC tech will take into account to determine the size of your ductless AC unit:

  • The orientation of the room (ie north or south)
  • How many windows and doors are in the room
  • Carpet versus hardwood floors in the room
  • Ceiling height
  • The quality of insulation
  • Whether or not the room gets direct sunlight
  • Any additional heat sources in the room
  • If it is near a kitchen area

Texas HVAC technicians should also uniquely take into account the humid climate of the area and how that impacts heat dissipation requirements during their load calculations.

You’ll also want to determine how many rooms you want to have cooled. Ductless AC units are designed to cool a single room or area. So, while the number of rooms won’t determine the BTU size of the unit you need, it will help the technician to know how many units you need to have installed to meet your cooling demands.

What are BTUs?

BTU stands for British Thermal Unit and is a unit of heat. In technical speak, it is the amount of heat (in Fahrenheit) that can be produced by burning a single kitchen match.

When we refer to the size of the unit, we are generally referring to the BTUs required. That is why a load calculation is so important, which allows you to get the correct power or heat dissipation needed for a specific room.

How does square footage factor in?

The average ductless AC unit size for a home can vary depending on square footage. You could see a range between 18,000 to 30,000 BTUs for a home of 600 to 1,650 square feet.

By performing a load calculation, an HVAC technician ensures that you will get a correctly sized ductless AC unit for the specific room or area you’re having checked out.

However, as seen above, there are a lot of variables to take into account during the load calculation. Be warned: a technician that purely goes off of square footage could be grossly underestimating or overestimating the size of the unit you need.

Ready to get started on your ductless AC installation?

We know installing a ductless AC unit can be a big decision. That is why our technicians are ready to help you every step of the way, from the in-home estimate and load calculation, all the way to the final installation. Contact us for a hassle-free estimate and installation.