I have a japanese folding organ which is stored in its original wooden trunk. It is kept at the bottom of my bed, on carpet with plenty of air circulating around it. I have a small throw on top of the trunk, to protect the wood. I have placed moisture crystals inside the trunk as I found that mould was beginning to appear inside, and the outside of the wooden trunk was also showing signs of mould growth. I would obviously like to keep this item in good condition as it is a family heirloom and was my mothers pride and joy. I have spoken to various friends and colleagues and can find no answer to why I have this problem, and as the wood is a warm substance, and it is standing on a warm surface(carpet with wood flooring underneath) and is well ventilated all around, dont know what else I can do. Our flat is well ventilated and have no real problems with damp elsewhere. comments and replies would be most appreciated.