In the southern United States, regions like Louisiana, Texas, Florida, and Georgia consider keeping the air conditioner "on all the time" to be almost common sense during the summer.

Many people even leave the air conditioner running while they are away on vacation, locking the doors behind them. This is to prevent indoor temperatures from rising excessively, setting it higher than usual at around 80 to 88 degrees. This helps to avoid damage to household structures like furniture, paint, and wallpaper due to high indoor temperatures and humidity while the house is unoccupied.

Additionally, most homes in the southern U.S. have central HVAC systems (Heating, Ventilation, Air Conditioning), which means they are designed to be completely sealed rather than relying on window ventilation, with indoor air circulating only through mechanical means. It is said that keeping the air conditioner on at a low setting all day is more energy-efficient than turning it off and then back on at a high setting. Ultimately, the flow of indoor air, air purification, and temperature maintenance all depend on the air conditioner, making keeping it on more economical.

High Heat and Humidity Day and Night

• In the southern region (e.g., Louisiana, Texas, Florida, Georgia), summer daytime temperatures reach 95 to 107 degrees, with humidity levels rising to 60 to 90%.

• When humidity is high, the perceived temperature can exceed 113 degrees → sweat does not dry, increasing the risk of heatstroke.

Homes Designed Around Air Conditioning

• Most homes in the southern U.S. have HVAC systems as standard (Heating, Ventilation, Air Conditioning: integrated heating and cooling).

• They are designed for sealed structures → mechanical cooling rather than window ventilation.

Mold/Insect/Humidity Prevention

• If humidity remains above 60%, mold on indoor wallpaper, odors, and furniture damage can occur.

• Especially in coastal areas of Florida and Texas, air conditioning serves as a tool to prevent mold.

Relatively Low Electricity Costs

• In some southern states, electricity costs are lower than in the Northeast/West, and the higher the humidity, the more the indoor temperature needs to be lowered for comfort.

  ※ In areas with low humidity (like Arizona), the same temperature feels cooler.

For these reasons, in the southern United States (Texas, Florida, Louisiana, Georgia, etc.), air conditioning is kept on all day during the hot weather season.