Maintaining your air conditioner is crucial if you want it to function properly. The first step is to locate your condenser unit, which is typically on a concrete slab just outside of the home. It looks like a big, boxy unit. This is the first component of your air conditioning system. The second component is the evaporator. It is not as easy to find as the condenser. The evaporator coil is mounted inside of your air conditioner’s main duct, usually right above the furnace.