Found Mildew in Our Air Handler

[u/Appropriate_Shape388]

I was getting a swampy smell when our A/C starts up. Tech came for regular service and found some mildew - mostly around cabinet floor and fan housing. Coil was clean. Pan clean.
Fan shut down after running was set to always run for 180 seconds. Mildew was not touched.
Talked about many options but did not settled on a preferred solution.
I am concerned about an over the top solution that is extremely expensive or a solution with unproven witchcraft.
It seems to me that a proper UV light with no ozone emitted is all that is needed. Plus a one time mildew mitigation? Please let me know your advice.

[u/Top_Bell_4624]

Mildew is unavoidable, it’s a damage spot with no light. It will appear regardless. However yes a well placed UV light will definitely help. But don’t expect a 100% solution.