Store Refrigerator, Keeps Doors Open How Often
I have an unused fridge in our shop that my son always closes.  I open it but it may not be until a weekend when I find it. So I can say it has been out there for 3 years and regularly is closed on a Monday or Tuesday and I find it on Friday or Saturday. It is a backup we had repaired so I don’t need it, but may so I want it clean. 1 time it started growing mold but sure how long it was closed. I added a bowl of baking soda to each side and doors are open at least 2 days per week, result with no mold for ~3 years. The one time mold did grow, I was gone for 2 months. I added baking soda after that with no issues so far (I did add new baking soda about a year ago and probably should again. I live in Oregon so relative humidity is not high like back East. But I would say a few days a week of being open have worked so far.