Air conditioners at home or in the workplace often cause disputes between those who crave a well-chilled environment and others who start to display cold symptoms at the slightest drop in temperature. But a properly maintained air conditioner can make everyone happy. Experts recommend professional service once a year for air conditioners in workplaces with smokers and every two years in smaller spaces such as bedrooms, where people usually don’t smoke. Beyond that, people who own air conditioners should remove, clean and reinstall the filters regularly every two weeks. As for the ideal temperature, opinions vary and there is no official limit. Experts recommend 25-26 Celsius (77-79 Fahrenheit), while some doctors suggest 22C (72F), but all of them advise that there not be a huge difference from the external temperature. For instance, if it is 40C (104F) outdoors, the unit should be set at 26-28C (79-82F) and not at 20C (68F), because the transition from a very warm to a very cool atmosphere is not good for the body. Poorly maintained air conditioners can harm the health, especially of the elderly and the chronically ill. «If units – especially those in public places or workplaces – leak, there is a risk of germs which can cause serious respiratory diseases such as legionnaire’s disease,» Vassilis Polychronidis, head of the Third Pneumonology Clinic at the Sismanogleio Hospital, told Kathimerini. Other diseases that may affect the lungs due to poorly maintained air conditioners are allergic bronchitis or bronchiolitis, which cause heavy coughing and dyspnea and are treated with oxygen and cortisone. These illnesses often require hospital treatment. People with bronchial asthma or chronic bronchitis could see their symptoms worsen if they are exposed to poorly maintained units. Inhaling very cold air can cause asthma attacks even in those who are not predisposed to them. Other effects of bad air conditioning are chills in the neck, chest and face. «Luckily, we have few cases of illnesses that can be attributed directly to air conditioners,» Polychronidis said. Legionnaire’s disease was first described some decades ago in the US when there was a mass outbreak of pneumonia at a hotel. The Legionella microbe had infested the air-conditioning system. The disease is contracted by inhaling or ingesting microscopic droplets of water containing Legionella. There is no evidence that it can be transmitted from one person to another. Diseases such as this can be prevented by proper planning, maintenance and disinfecting of water pipes in large buildings and air conditioners that use water.