A dirty AC coil will make it cost more to cool your home and get less cooling than you are paying for. The way an air conditioner cools your home is by taking heat out, not adding coolness. The condenser coil and evaporator are then components that make the heat transfer happen and since they are exposed to outside and inside elements, its easy for them to get full of dust and dirt inhibiting optimal heat transfer. The inside evaporator is constantly wet, which provides great breeding ground for mold and mold growth can eventually obstruct airflow. Cleaning the inside coil is not something that you can do unless you are a certified HVAC technician because of the way it is set up and sealed off. Leaving your coils dirty will make the system work harder and break more often so call Bartlett Heating and Air today to schedule your clean and check!