AC in Florida: 5 myths that cost you money
In Florida the AC runs almost all year, so small habits add up on the power bill. Here are five things a lot of people believe, and what the experts actually say.
Myth 1: “Closing vents in empty rooms saves money”
A Lawrence Berkeley National Laboratory study of forced-air systems found the opposite in a typical house with the ducts outside the living space, like in the attic: closing registers made energy use go up, because more air leaked out of the ducts. The same study warns that with too many closed, the AC coil can freeze. Keep vents open and free of furniture and curtains.
Myth 2: “A bigger AC cools better”
An oversized unit cools the air fast and shuts off before it can pull the moisture out, so the house feels damp and clammy. The U.S. Department of Energy warns that this on-and-off cycling hurts both efficiency and humidity control, and a Florida study it cites found that units 50% or more oversized used about 9% more electricity for cooling.
Myth 3: “Ceiling fans cool the room”
Fans cool people, not rooms: the breeze makes your skin feel cooler. With a ceiling fan on, the University of Florida’s extension experts say you can set the AC about 4°F higher and feel just as comfortable. Turn the fan off when you leave the room.
Myth 4: “The filter can wait”
A dirty filter makes the whole system work harder. ENERGY STAR says to check it every month, especially in the summer, and to change it at least every three months.
Myth 5: “If it still cools, it doesn’t need a checkup”
ENERGY STAR recommends a tune-up once a year, the way you’d service a car. In Florida, also keep the drain line clear: a clogged line can leak water into the ceiling or the floor, and many systems shut off when it backs up.
Have an older AC?
Some older systems use a refrigerant called R-22. Its production and import in the U.S. ended on January 1, 2020. You can keep using your system, but it runs on recycled refrigerant from now on, so ask your technician to check for leaks during maintenance.
When to call an AC pro
- It blows warm air, or the airflow is weak.
- There’s ice on the copper lines or the indoor unit.
- Water is leaking around the indoor unit.
- It turns on and off every few minutes.
- It makes new noises, smells like something burning or keeps tripping the breaker. Turn it off first.
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Sources
- Lawrence Berkeley National Laboratory: register closing effects on forced air heating system performance
- U.S. Department of Energy: right-size heating and cooling equipment (PDF)
- University of Florida IFAS Extension: energy efficient homes, ceiling fans
- ENERGY STAR: heating and cooling tips
- U.S. EPA: residential air conditioning and the phaseout of R-22 (PDF)
This guide is general information, not legal or professional advice. Rules change, so check the sources and ask a licensed pro about your home.
