I arrived for a red member ac pm. I first spoke with the homeowner and found that the return filters make a sucking noises when the system comes on. I inspect the system located in the attic and found the the 4 ton system to be rusted on two 14†returns. I recommend to have both existing returns increased and to add one more return to the home. I gave the homeowner option on doing one or both as recommendations to correct the noise issue with the returns grills. I inspected the condenser and found to issue with the systems operation. I checked the furnace and evaporator coil and for no issues. This systems or running to the best of its abilities at this time.