When you are looking for a self storage checking the condition of the gasket (rubber tube on the bottom of the door) is very important.  This seemingly useless piece of material actually helps to seal your belongings tightly behind the rollup door.

The first photo shows a dry cracked and deteriorating gasket.  If you are planning to store your items for a long period it may be worth it to check this annually.  Your self storage provider should change this out for you if needed.  If your gasket is not in good condition it will allow dust, debris, and even pests into your unit.  The second photo shows a gasket that does not extend the entire length of the door.  This will allow dust and debris into your storage unit. The final photo shows a storage unit that has a new gasket.  If you notice how it is compressed that is a good indication that there is a tight seal on your unit.  If you do have concerns about dust in your storage unit you can take additional steps to keep your items clean such as using furniture covers.  At Around the Corner Self Storage we always replace our gaskets as soon as they show any signs of wear.
deteriorating door gasket
Short door gasket
Quality new Door Gasket