Arrived on site to perform diagnostic on 4 year old unit. States that unit is not working or reaching setpoint inside the house. Also noticed that pipe outside has been freezing over. Target setpoint in the house is 64 degrees. Advised that unit is realistically not designed to reach that temperature. Also, it is unclear if thermostat is reading the correct temperature. System still has all original Ducting, and unit is in the garage leaving little room for return air. Found that filter had not been changed since the day the unit was installed, which was causing a airflow and refrigeration restriction. This would cause the unit to run inefficiently all day and eventually ice up. Refrigerant pressures and all electrical components are within range. Went over findings and recommendations.