Pausing call. On arrival thermostat was not functioning. I replaced the thermostat and checked refridgerant levels. Found a superheat of 4 with a saturated temp of 30 (evaporator coils temp). Blower is very dirty and is likely why the system is having performance issues. Ran inspection camera in supply plenum / coil and found bacterial growth on coil drip pan and top of coil. The dust and bacterial growth in the system is resulting in poor air quality.