When it comes to staying cool and comfortable in St. Louis during the summer, choosing the right size air conditioner is crucial. An improperly sized AC unit can lead to inefficiency, uneven cooling, higher energy bills, and more frequent repairs. At Galmiche & Sons, we specialize in helping homeowners choose the perfect air conditioner size for their space. This air conditioner size guide is designed to help you understand what goes into sizing an AC system and why it matters.
To learn more or for help selecting the best air conditioner unit for your home, contact our St. Louis heating and air conditioning experts today.
Why Air Conditioner Size Matters
One of the most common mistakes homeowners make is assuming that bigger is better. However, an oversized air conditioner unit will cycle on and off frequently, leading to poor humidity control, higher energy consumption, and unnecessary wear and tear. Conversely, an undersized unit will struggle to cool your space, running continuously and still not delivering adequate comfort.
Getting the right size air conditioner ensures:
- Optimal energy efficiency
- Consistent indoor comfort
- Lower maintenance and repair needs
- Longer system lifespan
Factors That Determine the Right AC Size
Several key variables go into determining the correct AC size for your home. These include:
Home Square Footage
The size of your home is one of the first considerations. As a general rule of thumb, it takes about 20 BTUs (British Thermal Units) per square foot to cool a space effectively. However, this can vary based on your climate and insulation levels.
Approximate Sizing Chart:
- 600 – 1,000 sq. ft. = 1.5 to 2 tons
- 1,000 – 1,500 sq. ft. = 2 to 2.5 tons
- 1,500 – 2,000 sq. ft. = 3 to 3.5 tons
- 2,000 – 2,500 sq. ft. = 4 to 5 tons
Insulation Quality
Homes with excellent insulation will retain cool air more efficiently, possibly requiring a smaller system than homes with poor insulation. This is especially important in older St. Louis homes, which may have outdated insulation.
Ceiling Height
Standard ceiling heights are 8 feet. If your home has vaulted or higher ceilings, you will need a larger unit to account for the extra air volume.
Window Size and Exposure
Homes with large windows or many windows facing the sun will heat up faster, requiring a more powerful AC unit. Window treatments and shading options can help offset this effect.
Local Climate
In St. Louis, where summers are hot and humid, your AC system needs to not only cool but also dehumidify your home. This increases the demand on your air conditioner and must be factored into sizing.
Number of Occupants and Appliances
People and appliances generate heat. Homes with more residents or electronics may require additional cooling capacity.
Professional Load Calculation Is Key
While charts and estimates from this air conditioner size guide are helpful, the best way to determine your ideal AC size is with a Manual J load calculation performed by a licensed HVAC professional. At Galmiche & Sons, we use industry-standard tools and years of experience to accurately assess your home and recommend the perfect air conditioning system.
FAQs About AC Sizing
Can I install a larger AC unit for faster cooling?
What happens if my AC is too small?
Is a ductless system sized differently?
Need Help Choosing the Right AC Size in St. Louis?
Don’t guess when it comes to your comfort. Galmiche & Sons has been helping St. Louis homeowners with accurate HVAC sizing, installation, and service for decades. Let our experts guide you through every step of the process, from load calculations to equipment selection and installation.
Contact us today to schedule a consultation and find out what size air conditioner you really need to keep your home cool and energy efficient all summer long.
