Upon arrival client stated system will run and cool decently on mild days but when the temperature outside increases in the heat of the day it struggles to cool home. Investigated entire system to find the air handler is badly debris up with biological growth and suet from previous house fire. Performed magnohelic test to find System is struggling for air and having a difficult time distributing the air on supply and return side. System needs to be pulled and chemically cleaned but made client aware of system being 16 yrs old and could potentially cause major issues (manhandling) system outside to be chemically cleaned. I advised replacement and gave options for repairs, repairs with duct cleaning, and system replacement options. Client stated he needs to talk with wife and will contact us back if he chooses to proceed with any work.