We're in the process of reducting our house for a central HVAC system.
We have an insulated "cold room" in the basement that had an outbreak of green mold in the past, probably from an old fridge but we're not sure. The room still smells funny after cleaning and humidity always peaks above 60% relative humidity each summer. There are no visible spores but we're pretty sure the problem is still there.
We want to leverage the HVAC system to permanently solve this mold problem by trying to lower the humidity in the room but we're afraid that installing a return duct in the room will spread mold spores into the insulated HVAC ducts (which are impossible to clean) and infect the rest of the house.