UV lighting in air conditioner units help to kill unseen pollutants, micro bacterial germs, before they get the chance to circulate around the house. Mold and other contaminants like to grow around the cooling coils in the air conditioner unit. The UV lighting system can kill unwanted particles that float around the unit and house. This helps to eliminate allergies, colds and other viruses from your home. These UV lights are extremely important to keep the air in coming out of the air conditioner clean. It is important to make sure these are working correctly. The bulbs effectiveness lasts about a year. If you think your lights need to be replaced, it is best to call Air America and they can come out and change them.