AC System not reaching desired temperature in home. Did a thorough evaluation of AC system. Noticed that the indoor and outdoor coils were slightly dirty, pressures are off, getting a low superheat and V stat temperature which fluctuates to a higher superheat and then drops back down to a lower superheat. Checked airflow, air filters, clean, and client using a Merv 5 air filter. Duct sizing is OK, however, the evaporator coil is in very poor condition. There is a restriction in evaporator coil. One side is getting colder than the other side. System is 18 years old and uses R 22 refrigerant which is obsolete. Advised client that system needs to be replaced. Gave client estimates for replacement, however, homeowner who is the father is not there to make decision. Emailed estimates and client will get back to us.