AC Sizing Guide: What Size AC Unit Do I Need?

AC units aren't one-size-fits-all. Even two houses with similar square footage can require different sizes based on several factors, from how many people live in each one to the direction the home faces.

Some people make the mistake of assuming a physically larger AC unit is stronger than a smaller one. However, the real way to size an AC is based on its British thermal units (BTU) rating. Even then, because houses can have such different BTU needs, the best way to determine the right AC size is by seeking out a certified technician to perform a Manual J load calculation.

Understanding what goes into a J-load calculation is helpful when assessing what size AC unit you need. This guide dives into several key topics, including:

• What a J Load calculation is
• How a J Load calculation is done
• Why proper AC sizing is necessary
• Things to look for in a reputable AC company

Some people may insist that you can get the right AC size by comparing the BTU to your home size, but true HVAC pros know this doesn't give you the most accurate answer.

Find the perfect size AC unit for your home. Give Jon Wayne a call today!

At Jon Wayne, we stand for integrity, honesty, and convenience. That's why our NATE-certified technicians are trained to do the job right the first time. Let them guide you in choosing the best AC unit size for your home and help with its installation from start to finish!

Sometimes referred to as an “HVAC load calculation”, a Manual J load calculation determines the correct size of an HVAC unit to sufficiently control a home's climate. It looks beyond the square footage and considers other factors that may impact heating and cooling.

A skilled technician will look at all aspects of your home and provide insight into which HVAC units you should consider.

Because a Manual J load calculation typically utilizes specialized software and extensive considerations about your home's construction, it should be performed by a professional. Your trained technician will weigh factors such as:

• The number, size, and types of doors and windows in the home
• How well-insulated your home is
• The height and type of ceilings
• The materials used to construct your home and roof
• The surrounding climate
• How many people live in the home
• Appliances that may heat up the home

Technicians follow several steps when calculating the load on the home, including:

1. Taking measurements of rooms, levels, ceiling heights, windows, and doors
2. Identifying the materials used in home construction
3. Performing a blower door test to determine air infiltration (a home with more air infiltration may need a larger system)
4. Entering measurements into specialized software that calculates the load and determines a home's recommended AC size

A properly sized AC unit is crucial. If you choose one that's too small, it will struggle to keep up and may run much longer or constantly without reaching the temperature set on the thermostat. If it's too big, the AC will short cycle. Both problems lead to excessive wear and tear and higher operating costs due to extra energy use.

A properly sized AC runs efficiently, reducing your energy bill. It's also more likely to keep the temperature in your home consistent and is designed to help reduce the wear and tear of your unit, potentially extending the unit's longevity and minimizing the risk of needing costly AC repairs.

Hot Texas summers are no laughing matter, especially if you don't have a reliable AC. Choosing a reputable AC company is one of the best ways to ensure you get a unit suitable for your home's unique needs, along with proper installation. Consider factors such as:

• Good reviews
• Valid licensing and insurance
• Certified technicians
• Solid warranties
• Free estimates
• A high BBB rating
• Quick response times

In case you were wondering, Jon Wayne Service Company checks all these boxes. We’re also home to a professional team of engineers, whose sole function is verifying load calculations and sizing units for our customers before they’re installed.

Thousands of 5-star reviews can't be wrong. If it's time for a new AC installation, trust the team with 200 trucks on the road. Our skilled technicians are so confident in their work that we offer a 100% satisfaction guarantee.