Arrived to do a dual system performance maintenance. Set each system for cooling. Measured both systems static pressure measured a temperature split between return and supply air. Found that the upstairs system is operating with failing static pressure. Reached out to a field supervisor to finsih the diagnosis on this system. Went outside and verified refrigerant levels. Verified operation of all electronic and mechanical components. Rinsed coils free of debris. Went back inside and checked interior of the furnaces for cleanliness. Spoke with homeowner about the system. Air conditioning systems are operational at this time.