Ideally, portable air conditioners should only operate 8 to 12 hours daily. This shouldn’t be an issue if you size your unit correctly for the floor area you’re trying to cool. Signs that your air conditioner is being overworked include high humidity, leaks, strange noises, and extremely high electric bills. Choose models like the De’Longhi EX390LVYN to ensure adequate cooling capacity. With 700 square feet of cooling capacity, energy efficiency, and smart technology, it’s a better choice for large spaces.