Call for system not keeping up. On arrival system was off. I turned on to check operation and the system did energize. I checked the filter and blower wheel and found the blower wheel completely dirty, clogged and negatively impacting air flow and system performance. I pulled the blower out to see evaporator coil and it is also very dirty. would need to start with the blower cleaning and evaporator coil to get a accurate refrigerant readings, this is a 2 technician job, due to the age, condition, efficiency, amount of cleanings and the fact that R22 started phase out January 1, 2020.