2 systems AC performance tuneup. Inspect blowers, evaporators and ductwork. The furnaces are 2001 models. Downstairs evaporator coil and condenser are 2018. Upstairs evaporator and condenser are 2022 models. There is no mastic seal on the ductwork to the equipment. There is much air leakage coming out into the attic and attic air is being introduced into the condition space. verified primary drain lines are clear and flowing at this time. Check outdoor units. Refrigerant levels are good at this time. Tested run capacitors and contactors. Washed condenser coils. Changed out filters client supplied. The 20 x 25 by one Rex rack do not have doors. I used black duct tape to stop the infiltration of attic air into the conditioned space. I am recommending a 20 x 25 x 4 filtration.