In the southern region of the United States, Louisiana, Texas, Florida, and Georgia are areas where it is almost common sense to keep the air conditioning "on all the time" during the summer.

Even when leaving home for a trip, many people leave the air conditioning on and lock the doors. This is to prevent the indoor temperature from rising excessively, setting it higher than usual at around 80 to 88 degrees. This is to prevent damage to household structures like furniture, paint, and wallpaper due to excessive heat and humidity while the house is empty.

Moreover, most homes in the southern United States 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 conditioning on at a low level throughout the day is more energy-efficient than turning it off and then back on at a high level. Ultimately, the flow of indoor air, air purification, and temperature maintenance all depend on the air conditioning, making keeping it on more economical.

High Temperature and Humidity Day and Night

  • In the southern region (e.g., Louisiana, Texas, Florida, Georgia), summer daytime temperatures reach 35 to 42 degrees, with humidity rising to 60 to 90%.

  • When humidity is high, the perceived temperature exceeds 45 degrees → sweat does not dry, increasing the risk of heatstroke.

Homes Designed Around Air Conditioning

  • Most homes in the southern United States are equipped with HVAC systems as standard (Heating, Ventilation, Air Conditioning: integrated heating and ventilation).

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

Mold/Insect/Humidity Prevention

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

  • Especially in Florida and coastal 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 lower the indoor temperature needs to be 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.), when the hot weather season arrives, people keep the air conditioning on all day.