This house would not pass a Board of Health inspection. I regret that I didn’t take a picture of the fan blades on the DC Inverter before I cleaned the mold off them. I doubt the inside of the inverter is mold free. I could only get to the blades that open and close based on operation.
It’s my opinion that the moldy/musty smell is coming from the basement, in fact at one point it even smelled like sewage. Noticed this one night after having used the washer/dryer. Especially when you lay down at night in the main bedroom, as the head of the bed next to the wall is closest to the basement. The smell just comes up through the old wood floors. I slept with a mask on. I didn’t know what I was breathing in.