Summer’s here in many regions. Suddenly, you find that your current air conditioning system isn’t working anymore and a replacement is needed. Or, you’ve never had more than room or window air conditioners and want to invest in central air to help cool your home without requiring a unit in each bedroom and the main living areas.
The big question is, how much are you going to spend? How big of an AC system do you need? Use a Florida AC unit sizing calculator to be sure you don’t get a system that’s too big or too small for what you need.
The Risks of an Oversized System
When a unit is oversized, it turns on quickly, runs for a short time, and turns back off again. The more it turns on and off, the faster components wear out. You may think that you’re going to save money by having an AC that’s bigger than you need. Because it wears out faster, you’re actually wasting money on repairs and replacements.
It’s also not running long enough to properly remove humidity, so you risk the build-up of mold and mildew from having a damp home. The impact mold has on your health is alarming. Asthma, skin rashes, nasal congestion, fatigue, and headaches are just a few of the symptoms you can experience.
What About an Undersized System?
If an oversized system is bad, how can a system that’s smaller than you need be just as detrimental? The system never shuts off. It’s running all of the time to cool your home down, but it can’t do what it’s supposed to. You end up with warm spots within your home, and your power bills will be higher because your system is running constantly.
You also experience the same wear and tear from excessive use. Parts will wear out fast and require replacement. The AC unit won’t last as long, so you spend more cash on repairs and replacements.
Many people find themselves in the fairy-tale Goldilocks situation where it’s too big, too small, and nothing seems just right. How do you find the right size air conditioner for your home’s size and build quality?
Use Our Florida AC Unit Sizing Calculator to Best Understand the Size You Need
Most people believe the best way to determine AC size is simply by looking at the square footage in the home. They take the square footage and subtract, if needed, the basement and garage area. Divide that number by 600 to determine the AC’s Ton size. If your home is 1,800 square feet after you subtract the garage space, you’d want a 3 Ton system.
The formula to determine AC unit sizing in Florida is trickier than that. It involves your home’s square footage, the insulation grade, sun exposure, number of windows and what type they are, the height of your ceilings, and the SEER rating of the AC unit. It also considers the number of heat-generation appliances in the home, people living in the home, etc. This is known as the Manual J professional load calculation. It’s not an easy formula for a layperson.
What is the SEER Rating? It stands for Seasonal Energy Efficiency Ratio. It’s the maximum efficiency rating that tells you exactly how efficient the AC system is. Most air conditioners fall in the range of 13 to 21.
To be an ENERGY STAR model, the SEER rating must be 14.5 or higher. Florida AC systems have to be rated 14 SEER or higher to meet the U.S. Department of Energy minimum standards.
An AC unit can only be as efficient as your home’s ductwork and vents allow. If you haven’t had them cleaned and sealed or restored if needed, make sure that’s part of the installation process.
The other number to pay attention to is the AC’s BTUs and Tons. A British Thermal Unit (BTU) is a measurement of the energy that’s needed to increase one pound of water by one degree (Fahrenheit). A Ton is 12,000 BTUs. In terms of air conditioners, the BTUs help calculate how much airflow is needed to keep the indoor temperature at 78 degrees F.
Most homes need a central AC unit that is 2 or 2.5 Tons. A 1.5 Ton system is the smallest central air conditioning size you’ll come across. Air conditioner sizes are as follows:
- 18,000 BTUs – 1.5 Tons
- 24,000 BTUs – 2 Tons
- 30,000 BTUs – 2.5 Tons
- 36,000 BTUs – 3 Tons
- 48,000 BTUs – 4 Tons
- 60,000 BTUs – 5 Tons
Knowing the right size air conditioner requires some information. You first need to know the size of your home or the area of the home you plan to cool. When was your home built? If it’s an ENERGY STAR qualified home, it’s insulated to keep outside air from getting into the home.
EnergyStar.gov also breaks things down by the area you live in. Average humidity and temperatures in Florida also impact the work an air conditioner does to keep your home cool and dehumidified. In coastal regions where there is plenty of airflow, an air conditioner may not run as much as in an inland zone where the humidity builds up quickly.
This Florida AC sizing chart can help you better understand the size of the air conditioner that’s right for your home. It’s not anywhere near as precise as a Manual J. calculation by an air conditioning professional, but it’s a start. When you’re right on the cusp between measurements, a lot of the decision to size up or down depends on your home’s windows, insulation quality, and ceiling heights.
|Florida Home Size||Tons||BTUs|
|600 to 900 sq. ft.||1.5||18,000|
|901 to 1,200 sq. ft.||2||24,000|
|1,201 to 1,500 sq. ft.||2.5||30,000|
|1,501 to 1,800 sq. ft.||3||36,000|
|1,801 to 2,100 sq. ft||3.5||42,000|
|2,101 to 2,400 sq. ft.||4||48,000|
|2,401 to 3,000 sq. ft.||5||60,000|
It’s time to replace your air conditioning unit or you want to add one to your home. Work with professional air conditioner technicians to ensure you get an air conditioner that isn’t too large or too small. An oversized or undersized unit wastes energy and wears out faster.
By choosing professionals from All Year Cooling, your system matches your needs and avoids frustrating malfunctions. Ask us about our limited-time AC coupon offer for same-day installations for new customers.