Customer had complaints of persistent indoor odors and sinus irritation. I conducted an IAQ inspection and installed a Pure AirX UV light in the air handler to target microbial buildup. Additionally, I treated the drain pan with Pure AirX tablets to prevent bacterial slime and blockages. I also inspected the return plenum for leaks and sealed minor gaps to prevent unfiltered air infiltration. IAQ levels should now improve steadily with active UV sanitation.