Hi. I have not used these, however I was curious after reading your post and was reading through their website.

I believe that, as long as the individual humidipaks are left in their individual wrappers. they can be stored anywhere. You probably wouldn't want to store them near a computer, light, appliance or anything else that generates heat because they will dry out faster inside the wrappers. I also believe that you would not need to use these around seeds because you want to keep seeds in a cool, dry place. I believe these would cause too much humidity for seeds.