A few years ago my neighbor had a small barn built on his property.
He said that it was going to be used for storage and within no time he had it filled to the brim. He had stuff from his parents’ house and his grandparents too that needed to be kept and he said he didn’t want to pay for a climate controlled storage unit any longer. He assumed that the items would be fine so long as they were kept up off the ground on shelves. Many of the items were keepsake ones and photos too. I warned him that the change of temperature from summer to winter and back to summer could damage these things but he insisted that it would be fine. After a year or so he wanted to go through some of the boxes and pass items on to his kids. When he started looking through things he realized that many had mildewed because of the humidity that had built up in the shed when it constantly heated and cooled. This is why his parents had kept the items in a climate controlled space. Precious memories were now lost and items ruined that could not be replaced. I felt bad for him when he told me about it and suggested that he put in some sort of small dehumidifier at the very least to help control the humidity. The barn has electricity anyway so it wouldn’t be hard to do this and it could help to preserve the items that were not lost. Either that, or, he could move all of the stuff into his basement where it would be safe too. Of course he doesn’t want to give up his man cave for that.